From 0eea8c885743575b0e93a98846b3663e9903aa66 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Coutable?= <remy@rymai.me>
Date: Thu, 30 Jun 2016 17:34:19 +0200
Subject: [PATCH 01/25] Support slash commands in noteable description and
 notes
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Some important things to note:

- commands are removed from noteable.description / note.note
- commands are translated to params so that they are treated as normal
  params in noteable Creation services
- the logic is not in the models but in the Creation services, which is
  the right place for advanced logic that has nothing to do with what
  models should be responsible of!
- UI/JS needs to be updated to handle notes which consist of commands
  only
- the `/merge` command is not handled yet

Other improvements:

- Don't process commands in commit notes and display a flash is note is only commands
- Add autocomplete for slash commands
- Add description and params to slash command DSL methods
- Ensure replying by email with a commands-only note works
- Use :subscription_event instead of calling noteable.subscribe
- Support :todo_event in IssuableBaseService

Signed-off-by: Rémy Coutable <remy@rymai.me>
---
 CHANGELOG                                     |   1 +
 ...o_complete.js => gfm_auto_complete.js.es6} |  38 ++-
 app/assets/javascripts/notes.js               |   7 +-
 .../stylesheets/framework/markdown_area.scss  |   5 +
 app/controllers/projects/notes_controller.rb  |   2 +-
 app/controllers/projects_controller.rb        |   3 +-
 app/finders/todos_finder.rb                   |   2 +-
 app/services/issuable_base_service.rb         |  81 +++++--
 app/services/issues/create_service.rb         |  20 +-
 app/services/merge_requests/create_service.rb |  25 +-
 app/services/notes/create_service.rb          |  50 +++-
 app/services/projects/autocomplete_service.rb |   4 +
 .../slash_commands/interpret_service.rb       | 133 +++++++++++
 doc/workflow/README.md                        |   1 +
 doc/workflow/slash_commands.md                |  28 +++
 lib/gitlab/email/handler/base_handler.rb      |   1 +
 lib/gitlab/slash_commands/dsl.rb              |  76 ++++++
 lib/gitlab/slash_commands/extractor.rb        |  59 +++++
 .../issues/user_uses_slash_commands_spec.rb   |  59 +++++
 .../user_uses_slash_commands_spec.rb          |  59 +++++
 spec/fixtures/emails/commands_only_reply.eml  |  40 ++++
 .../email/handler/create_note_handler_spec.rb |   9 +
 spec/lib/gitlab/slash_commands/dsl_spec.rb    | 110 +++++++++
 .../gitlab/slash_commands/extractor_spec.rb   | 177 ++++++++++++++
 spec/services/issues/create_service_spec.rb   |   2 +
 .../merge_requests/create_service_spec.rb     |  11 +-
 spec/services/notes/create_service_spec.rb    |  23 +-
 .../slash_commands/interpret_service_spec.rb  | 217 ++++++++++++++++++
 ..._service_slash_commands_shared_examples.rb |  83 +++++++
 ...issuable_slash_commands_shared_examples.rb | 170 ++++++++++++++
 ..._service_slash_commands_shared_examples.rb | 116 ++++++++++
 31 files changed, 1553 insertions(+), 59 deletions(-)
 rename app/assets/javascripts/{gfm_auto_complete.js => gfm_auto_complete.js.es6} (86%)
 create mode 100644 app/services/slash_commands/interpret_service.rb
 create mode 100644 doc/workflow/slash_commands.md
 create mode 100644 lib/gitlab/slash_commands/dsl.rb
 create mode 100644 lib/gitlab/slash_commands/extractor.rb
 create mode 100644 spec/features/issues/user_uses_slash_commands_spec.rb
 create mode 100644 spec/features/merge_requests/user_uses_slash_commands_spec.rb
 create mode 100644 spec/fixtures/emails/commands_only_reply.eml
 create mode 100644 spec/lib/gitlab/slash_commands/dsl_spec.rb
 create mode 100644 spec/lib/gitlab/slash_commands/extractor_spec.rb
 create mode 100644 spec/services/slash_commands/interpret_service_spec.rb
 create mode 100644 spec/support/issuable_create_service_slash_commands_shared_examples.rb
 create mode 100644 spec/support/issuable_slash_commands_shared_examples.rb
 create mode 100644 spec/support/note_create_service_slash_commands_shared_examples.rb

diff --git a/CHANGELOG b/CHANGELOG
index 96965a20f69..63ee7b91dcb 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -53,6 +53,7 @@ v 8.11.0 (unreleased)
   - Update version_sorter and use new interface for faster tag sorting
   - Optimize checking if a user has read access to a list of issues !5370
   - Store all DB secrets in secrets.yml, under descriptive names !5274
+  - Support slash commands in issue and merge request descriptions as well as comments. !5021
   - Nokogiri's various parsing methods are now instrumented
   - Add simple identifier to public SSH keys (muteor)
   - Admin page now references docs instead of a specific file !5600 (AnAverageHuman)
diff --git a/app/assets/javascripts/gfm_auto_complete.js b/app/assets/javascripts/gfm_auto_complete.js.es6
similarity index 86%
rename from app/assets/javascripts/gfm_auto_complete.js
rename to app/assets/javascripts/gfm_auto_complete.js.es6
index 2e5b15f4b77..21639c7c084 100644
--- a/app/assets/javascripts/gfm_auto_complete.js
+++ b/app/assets/javascripts/gfm_auto_complete.js.es6
@@ -223,7 +223,7 @@
           }
         }
       });
-      return this.input.atwho({
+      this.input.atwho({
         at: '~',
         alias: 'labels',
         searchKey: 'search',
@@ -249,6 +249,41 @@
           }
         }
       });
+      return this.input.atwho({
+        at: '/',
+        alias: 'commands',
+        displayTpl: function(value) {
+          var tpl = '<li>/${name}';
+          if (value.aliases.length > 0) {
+            tpl += ' <small>(or /<%- aliases.join(", /") %>)</small>';
+          }
+          if (value.params.length > 0) {
+            tpl += ' <small><%- params.join(" ") %></small>';
+          }
+          if (value.description !== '') {
+            tpl += '<small class="description"><i><%- description %></i></small>';
+          }
+          tpl += '</li>';
+          return _.template(tpl)(value);
+        },
+        insertTpl: function(value) {
+          var tpl = "\n/${name} ";
+          var reference_prefix = null;
+          if (value.params.length > 0) {
+            reference_prefix = value.params[0][0];
+            if (/^[@%~]/.test(reference_prefix)) {
+              tpl += '<%- reference_prefix %>';
+            }
+          }
+          return _.template(tpl)({ reference_prefix: reference_prefix });
+        },
+        suffix: '',
+        callbacks: {
+          sorter: this.DefaultOptions.sorter,
+          filter: this.DefaultOptions.filter,
+          beforeInsert: this.DefaultOptions.beforeInsert
+        }
+      });
     },
     destroyAtWho: function() {
       return this.input.atwho('destroy');
@@ -265,6 +300,7 @@
       this.input.atwho('load', 'mergerequests', data.mergerequests);
       this.input.atwho('load', ':', data.emojis);
       this.input.atwho('load', '~', data.labels);
+      this.input.atwho('load', '/', data.commands);
       return $(':focus').trigger('keyup');
     }
   };
diff --git a/app/assets/javascripts/notes.js b/app/assets/javascripts/notes.js
index 9ece474d994..99bc1a640a8 100644
--- a/app/assets/javascripts/notes.js
+++ b/app/assets/javascripts/notes.js
@@ -231,7 +231,12 @@
       var $notesList, votesBlock;
       if (!note.valid) {
         if (note.award) {
-          new Flash('You have already awarded this emoji!', 'alert');
+          new Flash('You have already awarded this emoji!', 'alert', this.parentTimeline);
+        }
+        else {
+          if (note.errors.commands_only) {
+            new Flash(note.errors.commands_only, 'notice', this.parentTimeline);
+          }
         }
         return;
       }
diff --git a/app/assets/stylesheets/framework/markdown_area.scss b/app/assets/stylesheets/framework/markdown_area.scss
index 96565da1bc9..edea4ad00eb 100644
--- a/app/assets/stylesheets/framework/markdown_area.scss
+++ b/app/assets/stylesheets/framework/markdown_area.scss
@@ -147,3 +147,8 @@
     color: $gl-link-color;
   }
 }
+
+.atwho-view small.description {
+  float: right;
+  padding: 3px 5px;
+}
diff --git a/app/controllers/projects/notes_controller.rb b/app/controllers/projects/notes_controller.rb
index 766b7e9cf22..f2422729364 100644
--- a/app/controllers/projects/notes_controller.rb
+++ b/app/controllers/projects/notes_controller.rb
@@ -125,7 +125,7 @@ class Projects::NotesController < Projects::ApplicationController
         id:     note.id,
         name:   note.name
       }
-    elsif note.valid?
+    elsif note.persisted?
       Banzai::NoteRenderer.render([note], @project, current_user)
 
       attrs = {
diff --git a/app/controllers/projects_controller.rb b/app/controllers/projects_controller.rb
index 47efbd4a939..64d31e4a3a0 100644
--- a/app/controllers/projects_controller.rb
+++ b/app/controllers/projects_controller.rb
@@ -145,7 +145,8 @@ class ProjectsController < Projects::ApplicationController
       milestones: autocomplete.milestones,
       mergerequests: autocomplete.merge_requests,
       labels: autocomplete.labels,
-      members: participants
+      members: participants,
+      commands: autocomplete.commands
     }
 
     respond_to do |format|
diff --git a/app/finders/todos_finder.rb b/app/finders/todos_finder.rb
index ff866c2faa5..fd859e134e5 100644
--- a/app/finders/todos_finder.rb
+++ b/app/finders/todos_finder.rb
@@ -17,7 +17,7 @@ class TodosFinder
 
   attr_accessor :current_user, :params
 
-  def initialize(current_user, params)
+  def initialize(current_user, params = {})
     @current_user = current_user
     @params = params
   end
diff --git a/app/services/issuable_base_service.rb b/app/services/issuable_base_service.rb
index 2d96efe1042..b365e19c4a8 100644
--- a/app/services/issuable_base_service.rb
+++ b/app/services/issuable_base_service.rb
@@ -69,14 +69,9 @@ class IssuableBaseService < BaseService
   end
 
   def filter_labels
-    if params[:add_label_ids].present? || params[:remove_label_ids].present?
-      params.delete(:label_ids)
-
-      filter_labels_in_param(:add_label_ids)
-      filter_labels_in_param(:remove_label_ids)
-    else
-      filter_labels_in_param(:label_ids)
-    end
+    filter_labels_in_param(:add_label_ids)
+    filter_labels_in_param(:remove_label_ids)
+    filter_labels_in_param(:label_ids)
   end
 
   def filter_labels_in_param(key)
@@ -85,23 +80,65 @@ class IssuableBaseService < BaseService
     params[key] = project.labels.where(id: params[key]).pluck(:id)
   end
 
+  def process_label_ids(attributes, base_label_ids: [], merge_all: false)
+    label_ids = attributes.delete(:label_ids) { [] }
+    add_label_ids = attributes.delete(:add_label_ids) { [] }
+    remove_label_ids = attributes.delete(:remove_label_ids) { [] }
+
+    new_label_ids = base_label_ids
+    new_label_ids |= label_ids if merge_all || (add_label_ids.empty? && remove_label_ids.empty?)
+    new_label_ids |= add_label_ids
+    new_label_ids -= remove_label_ids
+
+    new_label_ids
+  end
+
+  def merge_slash_commands_into_params!
+    command_params = SlashCommands::InterpretService.new(project, current_user).
+      execute(params[:description])
+
+    params.merge!(command_params)
+  end
+
+  def create_issuable(issuable, attributes)
+    issuable.with_transaction_returning_status do
+      attributes.delete(:state_event)
+      params[:author] ||= current_user
+      label_ids = process_label_ids(attributes, merge_all: true)
+
+      issuable.assign_attributes(attributes)
+
+      if issuable.save
+        issuable.update_attributes(label_ids: label_ids)
+      end
+    end
+  end
+
+  def create(issuable)
+    merge_slash_commands_into_params!
+    filter_params
+
+    if params.present? && create_issuable(issuable, params)
+      handle_creation(issuable)
+      issuable.create_cross_references!(current_user)
+      execute_hooks(issuable)
+    end
+
+    issuable
+  end
+
   def update_issuable(issuable, attributes)
     issuable.with_transaction_returning_status do
-      add_label_ids = attributes.delete(:add_label_ids)
-      remove_label_ids = attributes.delete(:remove_label_ids)
+      attributes[:label_ids] = process_label_ids(attributes, base_label_ids: issuable.label_ids)
 
-      issuable.label_ids |= add_label_ids if add_label_ids
-      issuable.label_ids -= remove_label_ids if remove_label_ids
-
-      issuable.assign_attributes(attributes.merge(updated_by: current_user))
-
-      issuable.save
+      issuable.update(attributes.merge(updated_by: current_user))
     end
   end
 
   def update(issuable)
     change_state(issuable)
     change_subscription(issuable)
+    change_todo(issuable)
     filter_params
     old_labels = issuable.labels.to_a
 
@@ -134,6 +171,18 @@ class IssuableBaseService < BaseService
     end
   end
 
+  def change_todo(issuable)
+    case params.delete(:todo_event)
+    when 'mark'
+      todo_service.mark_todo(issuable, current_user)
+    when 'done'
+      todo = TodosFinder.new(current_user).execute.find_by(target: issuable)
+      if todo
+        todo_service.mark_todos_as_done([todo], current_user)
+      end
+    end
+  end
+
   def has_changes?(issuable, old_labels: [])
     valid_attrs = [:title, :description, :assignee_id, :milestone_id, :target_branch]
 
diff --git a/app/services/issues/create_service.rb b/app/services/issues/create_service.rb
index 5e2de2ccf64..1b03d7f4c05 100644
--- a/app/services/issues/create_service.rb
+++ b/app/services/issues/create_service.rb
@@ -1,25 +1,19 @@
 module Issues
   class CreateService < Issues::BaseService
     def execute
-      filter_params
-      label_params = params.delete(:label_ids)
+      issue = project.issues.new
       request = params.delete(:request)
       api = params.delete(:api)
-      issue = project.issues.new(params)
-      issue.author = params[:author] || current_user
 
       issue.spam = spam_check_service.execute(request, api)
 
-      if issue.save
-        issue.update_attributes(label_ids: label_params)
-        notification_service.new_issue(issue, current_user)
-        todo_service.new_issue(issue, current_user)
-        event_service.open_issue(issue, current_user)
-        issue.create_cross_references!(current_user)
-        execute_hooks(issue, 'open')
-      end
+      create(issue)
+    end
 
-      issue
+    def handle_creation(issuable)
+      event_service.open_issue(issuable, current_user)
+      notification_service.new_issue(issuable, current_user)
+      todo_service.new_issue(issuable, current_user)
     end
 
     private
diff --git a/app/services/merge_requests/create_service.rb b/app/services/merge_requests/create_service.rb
index 96a25330af1..0b592cd5620 100644
--- a/app/services/merge_requests/create_service.rb
+++ b/app/services/merge_requests/create_service.rb
@@ -7,26 +7,19 @@ module MergeRequests
       source_project = @project
       @project = Project.find(params[:target_project_id]) if params[:target_project_id]
 
-      filter_params
-      label_params = params.delete(:label_ids)
-      force_remove_source_branch = params.delete(:force_remove_source_branch)
+      params[:target_project_id] ||= source_project.id
 
-      merge_request = MergeRequest.new(params)
+      merge_request = MergeRequest.new
       merge_request.source_project = source_project
-      merge_request.target_project ||= source_project
-      merge_request.author = current_user
-      merge_request.merge_params['force_remove_source_branch'] = force_remove_source_branch
+      merge_request.merge_params['force_remove_source_branch'] = params.delete(:force_remove_source_branch)
 
-      if merge_request.save
-        merge_request.update_attributes(label_ids: label_params)
-        event_service.open_mr(merge_request, current_user)
-        notification_service.new_merge_request(merge_request, current_user)
-        todo_service.new_merge_request(merge_request, current_user)
-        merge_request.create_cross_references!(current_user)
-        execute_hooks(merge_request)
-      end
+      create(merge_request)
+    end
 
-      merge_request
+    def handle_creation(issuable)
+      event_service.open_mr(issuable, current_user)
+      notification_service.new_merge_request(issuable, current_user)
+      todo_service.new_merge_request(issuable, current_user)
     end
   end
 end
diff --git a/app/services/notes/create_service.rb b/app/services/notes/create_service.rb
index 18971bd0be3..d7531a5d63b 100644
--- a/app/services/notes/create_service.rb
+++ b/app/services/notes/create_service.rb
@@ -11,13 +11,61 @@ module Notes
         return noteable.create_award_emoji(note.award_emoji_name, current_user)
       end
 
+      # We execute commands (extracted from `params[:note]`) on the noteable
+      # **before** we save the note because if the note consists of commands
+      # only, there is no need be create a note!
+      commands_executed = execute_slash_commands!(note)
+
       if note.save
         # Finish the harder work in the background
         NewNoteWorker.perform_in(2.seconds, note.id, params)
-        TodoService.new.new_note(note, current_user)
+        todo_service.new_note(note, current_user)
+      end
+
+      if commands_executed && note.note.blank?
+        note.errors.add(:commands_only, 'Your commands are being executed.')
       end
 
       note
     end
+
+    private
+
+    def execute_slash_commands!(note)
+      noteable_update_service = noteable_update_service(note.noteable_type)
+      return unless noteable_update_service
+
+      command_params = SlashCommands::InterpretService.new(project, current_user).
+        execute(note.note)
+
+      commands = execute_or_filter_commands(command_params, note)
+
+      if commands.any?
+        noteable_update_service.new(project, current_user, commands).execute(note.noteable)
+      end
+    end
+
+    def execute_or_filter_commands(commands, note)
+      final_commands = commands.reduce({}) do |memo, (command_key, command_value)|
+        if command_key != :due_date || note.noteable.respond_to?(:due_date)
+          memo[command_key] = command_value
+        end
+
+        memo
+      end
+
+      final_commands
+    end
+
+    def noteable_update_service(noteable_type)
+      case noteable_type
+      when 'Issue'
+        Issues::UpdateService
+      when 'MergeRequest'
+        MergeRequests::UpdateService
+      else
+        nil
+      end
+    end
   end
 end
diff --git a/app/services/projects/autocomplete_service.rb b/app/services/projects/autocomplete_service.rb
index 23b6668e0d1..e943d2ffbcb 100644
--- a/app/services/projects/autocomplete_service.rb
+++ b/app/services/projects/autocomplete_service.rb
@@ -15,5 +15,9 @@ module Projects
     def labels
       @project.labels.select([:title, :color])
     end
+
+    def commands
+      SlashCommands::InterpretService.command_definitions
+    end
   end
 end
diff --git a/app/services/slash_commands/interpret_service.rb b/app/services/slash_commands/interpret_service.rb
new file mode 100644
index 00000000000..2c92a4f7de5
--- /dev/null
+++ b/app/services/slash_commands/interpret_service.rb
@@ -0,0 +1,133 @@
+module SlashCommands
+  class InterpretService < BaseService
+    include Gitlab::SlashCommands::Dsl
+
+    # Takes a text and interpret the commands that are extracted from it.
+    # Returns a hash of changes to be applied to a record.
+    def execute(content)
+      @updates = {}
+
+      commands = extractor.extract_commands!(content)
+      commands.each do |command|
+        __send__(*command)
+      end
+
+      @updates
+    end
+
+    private
+
+    def extractor
+      @extractor ||= Gitlab::SlashCommands::Extractor.new(self.class.command_names)
+    end
+
+    desc 'Close this issue or merge request'
+    command :close do
+      @updates[:state_event] = 'close'
+    end
+
+    desc 'Reopen this issue or merge request'
+    command :open, :reopen do
+      @updates[:state_event] = 'reopen'
+    end
+
+    desc 'Reassign'
+    params '@user'
+    command :assign, :reassign do |assignee_param|
+      user = extract_references(assignee_param, :user).first
+      return unless user
+
+      @updates[:assignee_id] = user.id
+    end
+
+    desc 'Remove assignee'
+    command :unassign, :remove_assignee do
+      @updates[:assignee_id] = nil
+    end
+
+    desc 'Change milestone'
+    params '%"milestone"'
+    command :milestone do |milestone_param|
+      milestone = extract_references(milestone_param, :milestone).first
+      return unless milestone
+
+      @updates[:milestone_id] = milestone.id
+    end
+
+    desc 'Remove milestone'
+    command :clear_milestone, :remove_milestone do
+      @updates[:milestone_id] = nil
+    end
+
+    desc 'Add label(s)'
+    params '~label1 ~"label 2"'
+    command :label, :labels do |labels_param|
+      label_ids = find_label_ids(labels_param)
+      return if label_ids.empty?
+
+      @updates[:add_label_ids] = label_ids
+    end
+
+    desc 'Remove label(s)'
+    params '~label1 ~"label 2"'
+    command :unlabel, :remove_label, :remove_labels do |labels_param|
+      label_ids = find_label_ids(labels_param)
+      return if label_ids.empty?
+
+      @updates[:remove_label_ids] = label_ids
+    end
+
+    desc 'Remove all labels'
+    command :clear_labels, :clear_label do
+      @updates[:label_ids] = []
+    end
+
+    desc 'Add a todo'
+    command :todo do
+      @updates[:todo_event] = 'mark'
+    end
+
+    desc 'Mark todo as done'
+    command :done do
+      @updates[:todo_event] = 'done'
+    end
+
+    desc 'Subscribe'
+    command :subscribe do
+      @updates[:subscription_event] = 'subscribe'
+    end
+
+    desc 'Unsubscribe'
+    command :unsubscribe do
+      @updates[:subscription_event] = 'unsubscribe'
+    end
+
+    desc 'Set a due date'
+    params '<YYYY-MM-DD> | <N days>'
+    command :due_date do |due_date_param|
+      due_date = begin
+        Time.now + ChronicDuration.parse(due_date_param)
+      rescue ChronicDuration::DurationParseError
+        Date.parse(due_date_param) rescue nil
+      end
+
+      @updates[:due_date] = due_date if due_date
+    end
+
+    desc 'Remove due date'
+    command :clear_due_date do
+      @updates[:due_date] = nil
+    end
+
+    def find_label_ids(labels_param)
+      extract_references(labels_param, :label).map(&:id)
+    end
+
+    def extract_references(cmd_arg, type)
+      ext = Gitlab::ReferenceExtractor.new(project, current_user)
+      ext.analyze(cmd_arg, author: current_user)
+
+      ext.references(type)
+    end
+  end
+end
diff --git a/doc/workflow/README.md b/doc/workflow/README.md
index 49dec613716..17c04377b4c 100644
--- a/doc/workflow/README.md
+++ b/doc/workflow/README.md
@@ -6,6 +6,7 @@
 - [GitLab Flow](gitlab_flow.md)
 - [Groups](groups.md)
 - [Keyboard shortcuts](shortcuts.md)
+- [Slash commands](slash_commands.md)
 - [File finder](file_finder.md)
 - [Labels](../user/project/labels.md)
 - [Notification emails](notifications.md)
diff --git a/doc/workflow/slash_commands.md b/doc/workflow/slash_commands.md
new file mode 100644
index 00000000000..3bfc66309ba
--- /dev/null
+++ b/doc/workflow/slash_commands.md
@@ -0,0 +1,28 @@
+# GitLab slash commands
+
+Slash commands are textual shortcuts for common actions on issues or merge
+requests that are usually done by clicking buttons or dropdowns in GitLab's UI.
+You can enter these commands while creating a new issue or merge request, and
+in comments. Each command should be on a separate line in order to be properly
+detected and executed.
+
+Here is a list of all of the available commands and descriptions about what they
+do.
+
+| Command                    | Aliases             | Action       |
+|:---------------------------|:--------------------|:-------------|
+| `/close`                   | None                | Close the issue or merge request |
+| `/open`                    | `/reopen`           | Reopen the issue or merge request |
+| `/assign @username`        | `/reassign`         | Reassign |
+| `/unassign`                | `/remove_assignee`  | Remove assignee |
+| `/milestone %milestone`    | None                | Change milestone |
+| `/clear_milestone`         | `/remove_milestone` | Remove milestone |
+| `/label ~foo ~"bar baz"`   | `/labels`           | Add label(s) |
+| `/unlabel ~foo ~"bar baz"` | `/remove_label`, `remove_labels` | Remove label(s) |
+| `/clear_labels`            | `/clear_label`      | Clear all labels |
+| `/todo`                    | None                | Add a todo |
+| `/done`                    | None                | Mark todo as done |
+| `/subscribe`               | None                | Subscribe |
+| `/unsubscribe`             | None                | Unsubscribe |
+| `/due_date`                | None                | Set a due date |
+| `/clear_due_date`          | None                | Remove due date |
diff --git a/lib/gitlab/email/handler/base_handler.rb b/lib/gitlab/email/handler/base_handler.rb
index b7ed11cb638..7cccf465334 100644
--- a/lib/gitlab/email/handler/base_handler.rb
+++ b/lib/gitlab/email/handler/base_handler.rb
@@ -45,6 +45,7 @@ module Gitlab
 
         def verify_record!(record:, invalid_exception:, record_name:)
           return if record.persisted?
+          return if record.errors.key?(:commands_only)
 
           error_title = "The #{record_name} could not be created for the following reasons:"
 
diff --git a/lib/gitlab/slash_commands/dsl.rb b/lib/gitlab/slash_commands/dsl.rb
new file mode 100644
index 00000000000..3ded4109f2e
--- /dev/null
+++ b/lib/gitlab/slash_commands/dsl.rb
@@ -0,0 +1,76 @@
+module Gitlab
+  module SlashCommands
+    module Dsl
+      extend ActiveSupport::Concern
+
+      included do
+        @command_definitions = []
+      end
+
+      module ClassMethods
+        def command_definitions
+          @command_definitions
+        end
+
+        def command_names
+          command_definitions.flat_map do |command_definition|
+            [command_definition[:name], command_definition[:aliases]].flatten
+          end
+        end
+
+        # Allows to give a description to the next slash command
+        def desc(text)
+          @description = text
+        end
+
+        # Allows to define params for the next slash command
+        def params(*params)
+          @params = params
+        end
+
+        # Registers a new command which is recognizeable
+        # from body of email or comment.
+        # Example:
+        #
+        #   command :command_key do |arguments|
+        #     # Awesome code block
+        #   end
+        #
+        def command(*command_names, &block)
+          command_name, *aliases = command_names
+          proxy_method_name = "__#{command_name}__"
+
+          # This proxy method is needed because calling `return` from inside a
+          # block/proc, causes a `return` from the enclosing method or lambda,
+          # otherwise a LocalJumpError error is raised.
+          define_method(proxy_method_name, &block)
+
+          define_method(command_name) do |*args|
+            proxy_method = method(proxy_method_name)
+
+            if proxy_method.arity == -1 || proxy_method.arity == args.size
+              instance_exec(*args, &proxy_method)
+            end
+          end
+
+          private command_name
+          aliases.each do |alias_command|
+            alias_method alias_command, command_name
+            private alias_command
+          end
+
+          command_definition = {
+            name: command_name,
+            aliases: aliases,
+            description: @description || '',
+            params: @params || []
+          }
+          @command_definitions << command_definition
+
+          @description = nil
+          @params = nil
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/slash_commands/extractor.rb b/lib/gitlab/slash_commands/extractor.rb
new file mode 100644
index 00000000000..1a854b81aca
--- /dev/null
+++ b/lib/gitlab/slash_commands/extractor.rb
@@ -0,0 +1,59 @@
+module Gitlab
+  module SlashCommands
+    # This class takes an array of commands that should be extracted from a
+    # given text.
+    #
+    # ```
+    # extractor = Gitlab::SlashCommands::Extractor.new([:open, :assign, :labels])
+    # ```
+    class Extractor
+      attr_reader :command_names
+
+      def initialize(command_names)
+        @command_names = command_names
+      end
+
+      # Extracts commands from content and return an array of commands.
+      # The array looks like the following:
+      # [
+      #   ['command1'],
+      #   ['command3', 'arg1 arg2'],
+      # ]
+      # The command and the arguments are stripped.
+      # The original command text is removed from the given `content`.
+      #
+      # Usage:
+      # ```
+      # extractor = Gitlab::SlashCommands::Extractor.new([:open, :assign, :labels])
+      # msg = %(hello\n/labels ~foo ~"bar baz"\nworld)
+      # commands = extractor.extract_commands! #=> [['labels', '~foo ~"bar baz"']]
+      # msg #=> "hello\nworld"
+      # ```
+      def extract_commands!(content)
+        return [] unless content
+
+        commands = []
+
+        content.gsub!(commands_regex) do
+          commands << [$1, $2].flatten.reject(&:blank?)
+          ''
+        end
+
+        commands
+      end
+
+      private
+
+      # Builds a regular expression to match known commands.
+      # First match group captures the command name and
+      # second match group captures its arguments.
+      #
+      # It looks something like:
+      #
+      #   /^\/(?<cmd>close|reopen|...)(?:( |$))(?<args>[^\/\n]*)(?:\n|$)/
+      def commands_regex
+        /^\/(?<cmd>#{command_names.join('|')})(?:( |$))(?<args>[^\/\n]*)(?:\n|$)/
+      end
+    end
+  end
+end
diff --git a/spec/features/issues/user_uses_slash_commands_spec.rb b/spec/features/issues/user_uses_slash_commands_spec.rb
new file mode 100644
index 00000000000..47c4ce306e9
--- /dev/null
+++ b/spec/features/issues/user_uses_slash_commands_spec.rb
@@ -0,0 +1,59 @@
+require 'rails_helper'
+
+feature 'Issues > User uses slash commands', feature: true, js: true do
+  include WaitForAjax
+
+  it_behaves_like 'issuable record that supports slash commands in its description and notes', :issue do
+    let(:issuable) { create(:issue, project: project) }
+  end
+
+  describe 'issue-only commands' do
+    let(:user) { create(:user) }
+    let(:project) { create(:project, :public) }
+
+    before do
+      project.team << [user, :master]
+      login_with(user)
+      visit namespace_project_issue_path(project.namespace, project, issue)
+    end
+
+    describe 'adding a due date from note' do
+      let(:issue) { create(:issue, project: project) }
+
+      it 'does not create a note, and sets the due date accordingly' do
+        page.within('.js-main-target-form') do
+          fill_in 'note[note]', with: "/due_date 2016-08-28"
+          click_button 'Comment'
+        end
+
+        expect(page).not_to have_content '/due_date 2016-08-28'
+        expect(page).to have_content 'Your commands are being executed.'
+
+        issue.reload
+
+        expect(issue.due_date).to eq Date.new(2016, 8, 28)
+      end
+    end
+
+    describe 'removing a due date from note' do
+      let(:issue) { create(:issue, project: project, due_date: Date.new(2016, 8, 28)) }
+
+      it 'does not create a note, and removes the due date accordingly' do
+        expect(issue.due_date).to eq Date.new(2016, 8, 28)
+
+        page.within('.js-main-target-form') do
+          fill_in 'note[note]', with: "/clear_due_date"
+          click_button 'Comment'
+        end
+
+        expect(page).not_to have_content '/clear_due_date'
+        expect(page).to have_content 'Your commands are being executed.'
+
+        issue.reload
+
+        expect(issue.due_date).to be_nil
+      end
+    end
+  end
+
+end
diff --git a/spec/features/merge_requests/user_uses_slash_commands_spec.rb b/spec/features/merge_requests/user_uses_slash_commands_spec.rb
new file mode 100644
index 00000000000..890648f3860
--- /dev/null
+++ b/spec/features/merge_requests/user_uses_slash_commands_spec.rb
@@ -0,0 +1,59 @@
+require 'rails_helper'
+
+feature 'Merge Requests > User uses slash commands', feature: true, js: true do
+  include WaitForAjax
+
+  let(:user) { create(:user) }
+  let(:project) { create(:project, :public) }
+  let(:merge_request) { create(:merge_request, source_project: project) }
+  let!(:milestone) { create(:milestone, project: project, title: 'ASAP') }
+
+  it_behaves_like 'issuable record that supports slash commands in its description and notes', :merge_request do
+    let(:issuable) { create(:merge_request, source_project: project) }
+    let(:new_url_opts) { { merge_request: { source_branch: 'feature' } } }
+  end
+
+  describe 'adding a due date from note' do
+    before do
+      project.team << [user, :master]
+      login_with(user)
+      visit namespace_project_merge_request_path(project.namespace, project, merge_request)
+    end
+
+    it 'does not recognize the command nor create a note' do
+      page.within('.js-main-target-form') do
+        fill_in 'note[note]', with: "/due_date 2016-08-28"
+        click_button 'Comment'
+      end
+
+      expect(page).not_to have_content '/due_date 2016-08-28'
+    end
+  end
+
+  # Postponed because of high complexity
+  xdescribe 'merging from note' do
+    before do
+      project.team << [user, :master]
+      login_with(user)
+      visit namespace_project_merge_request_path(project.namespace, project, merge_request)
+    end
+
+    it 'creates a note without the commands and interpret the commands accordingly' do
+      page.within('.js-main-target-form') do
+        fill_in 'note[note]', with: "Let's merge this!\n/merge\n/milestone %ASAP"
+        click_button 'Comment'
+      end
+
+      expect(page).to have_content("Let's merge this!")
+      expect(page).not_to have_content('/merge')
+      expect(page).not_to have_content('/milestone %ASAP')
+
+      merge_request.reload
+      note = merge_request.notes.user.first
+
+      expect(note.note).to eq "Let's merge this!\r\n"
+      expect(merge_request).to be_merged
+      expect(merge_request.milestone).to eq milestone
+    end
+  end
+end
diff --git a/spec/fixtures/emails/commands_only_reply.eml b/spec/fixtures/emails/commands_only_reply.eml
new file mode 100644
index 00000000000..b64d851a79c
--- /dev/null
+++ b/spec/fixtures/emails/commands_only_reply.eml
@@ -0,0 +1,40 @@
+Return-Path: <jake@adventuretime.ooo>
+Received: from iceking.adventuretime.ooo ([unix socket]) by iceking (Cyrus v2.2.13-Debian-2.2.13-19+squeeze3) with LMTPA; Thu, 13 Jun 2013 17:03:50 -0400
+Received: from mail-ie0-x234.google.com (mail-ie0-x234.google.com [IPv6:2607:f8b0:4001:c03::234]) by iceking.adventuretime.ooo (8.14.3/8.14.3/Debian-9.4) with ESMTP id r5DL3nFJ016967 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=NOT) for <reply+59d8df8370b7e95c5a49fbf86aeb2c93@appmail.adventuretime.ooo>; Thu, 13 Jun 2013 17:03:50 -0400
+Received: by mail-ie0-f180.google.com with SMTP id f4so21977375iea.25 for <reply+59d8df8370b7e95c5a49fbf86aeb2c93@appmail.adventuretime.ooo>; Thu, 13 Jun 2013 14:03:48 -0700
+Received: by 10.0.0.1 with HTTP; Thu, 13 Jun 2013 14:03:48 -0700
+Date: Thu, 13 Jun 2013 17:03:48 -0400
+From: Jake the Dog <jake@adventuretime.ooo>
+To: reply+59d8df8370b7e95c5a49fbf86aeb2c93@appmail.adventuretime.ooo
+Message-ID: <CADkmRc+rNGAGGbV2iE5p918UVy4UyJqVcXRO2=otppgzduJSg@mail.gmail.com>
+In-Reply-To: <issue_1@localhost>
+References: <issue_1@localhost> <reply-59d8df8370b7e95c5a49fbf86aeb2c93@localhost>
+Subject: re: [Discourse Meta] eviltrout posted in 'Adventure Time Sux'
+Mime-Version: 1.0
+Content-Type: text/plain;
+ charset=ISO-8859-1
+Content-Transfer-Encoding: 7bit
+X-Sieve: CMU Sieve 2.2
+X-Received: by 10.0.0.1 with SMTP id n7mr11234144ipb.85.1371157428600; Thu,
+ 13 Jun 2013 14:03:48 -0700 (PDT)
+X-Scanned-By: MIMEDefang 2.69 on IPv6:2001:470:1d:165::1
+
+/close
+/unsubscribe
+
+
+On Sun, Jun 9, 2013 at 1:39 PM, eviltrout via Discourse Meta
+<reply+59d8df8370b7e95c5a49fbf86aeb2c93@appmail.adventuretime.ooo> wrote:
+>
+>
+>
+> eviltrout posted in 'Adventure Time Sux' on Discourse Meta:
+>
+> ---
+> hey guys everyone knows adventure time sucks!
+>
+> ---
+> Please visit this link to respond: http://localhost:3000/t/adventure-time-sux/1234/3
+>
+> To unsubscribe from these emails, visit your [user preferences](http://localhost:3000/user_preferences).
+>
diff --git a/spec/lib/gitlab/email/handler/create_note_handler_spec.rb b/spec/lib/gitlab/email/handler/create_note_handler_spec.rb
index a2119b0dadf..e2339c5e103 100644
--- a/spec/lib/gitlab/email/handler/create_note_handler_spec.rb
+++ b/spec/lib/gitlab/email/handler/create_note_handler_spec.rb
@@ -60,6 +60,15 @@ describe Gitlab::Email::Handler::CreateNoteHandler, lib: true do
     it "raises an InvalidNoteError" do
       expect { receiver.execute }.to raise_error(Gitlab::Email::InvalidNoteError)
     end
+
+    context 'because the note was commands only' do
+      let!(:email_raw) { fixture_file("emails/commands_only_reply.eml") }
+
+      it 'raises a CommandsOnlyNoteError' do
+        expect { receiver.execute }.not_to raise_error
+      end
+
+    end
   end
 
   context "when the reply is blank" do
diff --git a/spec/lib/gitlab/slash_commands/dsl_spec.rb b/spec/lib/gitlab/slash_commands/dsl_spec.rb
new file mode 100644
index 00000000000..f8abb35674d
--- /dev/null
+++ b/spec/lib/gitlab/slash_commands/dsl_spec.rb
@@ -0,0 +1,110 @@
+require 'spec_helper'
+
+describe Gitlab::SlashCommands::Dsl do
+  before :all do
+    DummyClass = Class.new do
+      include Gitlab::SlashCommands::Dsl
+
+      desc 'A command with no args'
+      command :no_args, :none do
+        "Hello World!"
+      end
+
+      desc 'A command returning a value'
+      command :returning do
+        return 42
+      end
+
+      params 'The first argument'
+      command :one_arg, :once, :first do |arg1|
+        arg1
+      end
+
+      desc 'A command with two args'
+      params 'The first argument', 'The second argument'
+      command :two_args do |arg1, arg2|
+        [arg1, arg2]
+      end
+
+      command :wildcard do |*args|
+        args
+      end
+    end
+  end
+  let(:dummy) { DummyClass.new }
+
+  describe '.command_definitions' do
+    it 'returns an array with commands definitions' do
+      expected = [
+        { name: :no_args, aliases: [:none], description: 'A command with no args', params: [] },
+        { name: :returning, aliases: [], description: 'A command returning a value', params: [] },
+        { name: :one_arg, aliases: [:once, :first], description: '', params: ['The first argument'] },
+        { name: :two_args, aliases: [], description: 'A command with two args', params: ['The first argument', 'The second argument'] },
+        { name: :wildcard, aliases: [], description: '', params: [] }
+      ]
+
+      expect(DummyClass.command_definitions).to eq expected
+    end
+  end
+
+  describe '.command_names' do
+    it 'returns an array with commands definitions' do
+      expect(DummyClass.command_names).to eq [
+        :no_args, :none, :returning, :one_arg,
+        :once, :first, :two_args, :wildcard
+      ]
+    end
+  end
+
+  describe 'command with no args' do
+    context 'called with no args' do
+      it 'succeeds' do
+        expect(dummy.__send__(:no_args)).to eq 'Hello World!'
+      end
+    end
+  end
+
+  describe 'command with an explicit return' do
+    context 'called with no args' do
+      it 'succeeds' do
+        expect(dummy.__send__(:returning)).to eq 42
+      end
+    end
+  end
+
+  describe 'command with one arg' do
+    context 'called with one arg' do
+      it 'succeeds' do
+        expect(dummy.__send__(:one_arg, 42)).to eq 42
+      end
+    end
+  end
+
+  describe 'command with two args' do
+    context 'called with two args' do
+      it 'succeeds' do
+        expect(dummy.__send__(:two_args, 42, 'foo')).to eq [42, 'foo']
+      end
+    end
+  end
+
+  describe 'command with wildcard' do
+    context 'called with no args' do
+      it 'succeeds' do
+        expect(dummy.__send__(:wildcard)).to eq []
+      end
+    end
+
+    context 'called with one arg' do
+      it 'succeeds' do
+        expect(dummy.__send__(:wildcard, 42)).to eq [42]
+      end
+    end
+
+    context 'called with two args' do
+      it 'succeeds' do
+        expect(dummy.__send__(:wildcard, 42, 'foo')).to eq [42, 'foo']
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/slash_commands/extractor_spec.rb b/spec/lib/gitlab/slash_commands/extractor_spec.rb
new file mode 100644
index 00000000000..fd1b30052ed
--- /dev/null
+++ b/spec/lib/gitlab/slash_commands/extractor_spec.rb
@@ -0,0 +1,177 @@
+require 'spec_helper'
+
+describe Gitlab::SlashCommands::Extractor do
+  let(:extractor) { described_class.new([:open, :assign, :labels, :power]) }
+
+  shared_examples 'command with no argument' do
+    it 'extracts command' do
+      commands = extractor.extract_commands!(original_msg)
+
+      expect(commands).to eq [['open']]
+      expect(original_msg).to eq final_msg
+    end
+  end
+
+  shared_examples 'command with a single argument' do
+    it 'extracts command' do
+      commands = extractor.extract_commands!(original_msg)
+
+      expect(commands).to eq [['assign', '@joe']]
+      expect(original_msg).to eq final_msg
+    end
+  end
+
+  shared_examples 'command with multiple arguments' do
+    it 'extracts command' do
+      commands = extractor.extract_commands!(original_msg)
+
+      expect(commands).to eq [['labels', '~foo ~"bar baz" label']]
+      expect(original_msg).to eq final_msg
+    end
+  end
+
+  describe '#extract_commands!' do
+    describe 'command with no argument' do
+      context 'at the start of content' do
+        it_behaves_like 'command with no argument' do
+          let(:original_msg) { "/open\nworld" }
+          let(:final_msg) { "world" }
+        end
+      end
+
+      context 'in the middle of content' do
+        it_behaves_like 'command with no argument' do
+          let(:original_msg) { "hello\n/open\nworld" }
+          let(:final_msg) { "hello\nworld" }
+        end
+      end
+
+      context 'in the middle of a line' do
+        it 'does not extract command' do
+          msg = "hello\nworld /open"
+          commands = extractor.extract_commands!(msg)
+
+          expect(commands).to be_empty
+          expect(msg).to eq "hello\nworld /open"
+        end
+      end
+
+      context 'at the end of content' do
+        it_behaves_like 'command with no argument' do
+          let(:original_msg) { "hello\n/open" }
+          let(:final_msg) { "hello\n" }
+        end
+      end
+    end
+
+    describe 'command with a single argument' do
+      context 'at the start of content' do
+        it_behaves_like 'command with a single argument' do
+          let(:original_msg) { "/assign @joe\nworld" }
+          let(:final_msg) { "world" }
+        end
+      end
+
+      context 'in the middle of content' do
+        it_behaves_like 'command with a single argument' do
+          let(:original_msg) { "hello\n/assign @joe\nworld" }
+          let(:final_msg) { "hello\nworld" }
+        end
+      end
+
+      context 'in the middle of a line' do
+        it 'does not extract command' do
+          msg = "hello\nworld /assign @joe"
+          commands = extractor.extract_commands!(msg)
+
+          expect(commands).to be_empty
+          expect(msg).to eq "hello\nworld /assign @joe"
+        end
+      end
+
+      context 'at the end of content' do
+        it_behaves_like 'command with a single argument' do
+          let(:original_msg) { "hello\n/assign @joe" }
+          let(:final_msg) { "hello\n" }
+        end
+      end
+
+      context 'when argument is not separated with a space' do
+        it 'does not extract command' do
+          msg = "hello\n/assign@joe\nworld"
+          commands = extractor.extract_commands!(msg)
+
+          expect(commands).to be_empty
+          expect(msg).to eq "hello\n/assign@joe\nworld"
+        end
+      end
+    end
+
+    describe 'command with multiple arguments' do
+      context 'at the start of content' do
+        it_behaves_like 'command with multiple arguments' do
+          let(:original_msg) { %(/labels ~foo ~"bar baz" label\nworld) }
+          let(:final_msg) { "world" }
+        end
+      end
+
+      context 'in the middle of content' do
+        it_behaves_like 'command with multiple arguments' do
+          let(:original_msg) { %(hello\n/labels ~foo ~"bar baz" label\nworld) }
+          let(:final_msg) { "hello\nworld" }
+        end
+      end
+
+      context 'in the middle of a line' do
+        it 'does not extract command' do
+          msg = %(hello\nworld /labels ~foo ~"bar baz" label)
+          commands = extractor.extract_commands!(msg)
+
+          expect(commands).to be_empty
+          expect(msg).to eq %(hello\nworld /labels ~foo ~"bar baz" label)
+        end
+      end
+
+      context 'at the end of content' do
+        it_behaves_like 'command with multiple arguments' do
+          let(:original_msg) { %(hello\n/labels ~foo ~"bar baz" label) }
+          let(:final_msg) { "hello\n" }
+        end
+      end
+
+      context 'when argument is not separated with a space' do
+        it 'does not extract command' do
+          msg = %(hello\n/labels~foo ~"bar baz" label\nworld)
+          commands = extractor.extract_commands!(msg)
+
+          expect(commands).to be_empty
+          expect(msg).to eq %(hello\n/labels~foo ~"bar baz" label\nworld)
+        end
+      end
+    end
+
+    it 'extracts command with multiple arguments and various prefixes' do
+      msg = %(hello\n/power @user.name %9.10 ~"bar baz.2"\nworld)
+      commands = extractor.extract_commands!(msg)
+
+      expect(commands).to eq [['power', '@user.name %9.10 ~"bar baz.2"']]
+      expect(msg).to eq "hello\nworld"
+    end
+
+    it 'extracts multiple commands' do
+      msg = %(hello\n/power @user.name %9.10 ~"bar baz.2" label\nworld\n/open)
+      commands = extractor.extract_commands!(msg)
+
+      expect(commands).to eq [['power', '@user.name %9.10 ~"bar baz.2" label'], ['open']]
+      expect(msg).to eq "hello\nworld\n"
+    end
+
+    it 'does not alter original content if no command is found' do
+      msg = 'Fixes #123'
+      commands = extractor.extract_commands!(msg)
+
+      expect(commands).to be_empty
+      expect(msg).to eq 'Fixes #123'
+    end
+  end
+end
diff --git a/spec/services/issues/create_service_spec.rb b/spec/services/issues/create_service_spec.rb
index 1ee9f3aae4d..fcc3c0a00bd 100644
--- a/spec/services/issues/create_service_spec.rb
+++ b/spec/services/issues/create_service_spec.rb
@@ -73,5 +73,7 @@ describe Issues::CreateService, services: true do
         end
       end
     end
+
+    it_behaves_like 'new issuable record that supports slash commands'
   end
 end
diff --git a/spec/services/merge_requests/create_service_spec.rb b/spec/services/merge_requests/create_service_spec.rb
index b84a580967a..c1e4f8bd96b 100644
--- a/spec/services/merge_requests/create_service_spec.rb
+++ b/spec/services/merge_requests/create_service_spec.rb
@@ -17,7 +17,7 @@ describe MergeRequests::CreateService, services: true do
         }
       end
 
-      let(:service) { MergeRequests::CreateService.new(project, user, opts) }
+      let(:service) { described_class.new(project, user, opts) }
 
       before do
         project.team << [user, :master]
@@ -74,5 +74,14 @@ describe MergeRequests::CreateService, services: true do
         end
       end
     end
+
+    it_behaves_like 'new issuable record that supports slash commands' do
+      let(:default_params) do
+        {
+          source_branch: 'feature',
+          target_branch: 'master'
+        }
+      end
+    end
   end
 end
diff --git a/spec/services/notes/create_service_spec.rb b/spec/services/notes/create_service_spec.rb
index 32753e84b31..36ca7d2bce8 100644
--- a/spec/services/notes/create_service_spec.rb
+++ b/spec/services/notes/create_service_spec.rb
@@ -4,22 +4,31 @@ describe Notes::CreateService, services: true do
   let(:project) { create(:empty_project) }
   let(:issue) { create(:issue, project: project) }
   let(:user) { create(:user) }
+  let(:opts) do
+    { note: 'Awesome comment', noteable_type: 'Issue', noteable_id: issue.id }
+  end
 
   describe '#execute' do
     context "valid params" do
       before do
         project.team << [user, :master]
-        opts = {
-          note: 'Awesome comment',
-          noteable_type: 'Issue',
-          noteable_id: issue.id
-        }
-
         @note = Notes::CreateService.new(project, user, opts).execute
       end
 
       it { expect(@note).to be_valid }
-      it { expect(@note.note).to eq('Awesome comment') }
+      it { expect(@note.note).to eq(opts[:note]) }
+
+      it_behaves_like 'note on noteable that supports slash commands' do
+        let(:noteable) { create(:issue, project: project) }
+      end
+
+      it_behaves_like 'note on noteable that supports slash commands' do
+        let(:noteable) { create(:merge_request, source_project: project) }
+      end
+
+      it_behaves_like 'note on noteable that does not support slash commands' do
+        let(:noteable) { create(:commit, project: project) }
+      end
     end
   end
 
diff --git a/spec/services/slash_commands/interpret_service_spec.rb b/spec/services/slash_commands/interpret_service_spec.rb
new file mode 100644
index 00000000000..fa0f65495ce
--- /dev/null
+++ b/spec/services/slash_commands/interpret_service_spec.rb
@@ -0,0 +1,217 @@
+require 'spec_helper'
+
+describe SlashCommands::InterpretService, services: true do
+  let(:project) { create(:project) }
+  let(:user) { create(:user) }
+  let(:issue) { create(:issue, project: project) }
+  let(:milestone) { create(:milestone, project: project, title: '9.10') }
+  let(:inprogress) { create(:label, project: project, title: 'In Progress') }
+  let(:bug) { create(:label, project: project, title: 'Bug') }
+
+  describe '#command_names' do
+    subject { described_class.command_names }
+
+    it 'returns the known commands' do
+      is_expected.to match_array([
+        :open, :reopen,
+        :close,
+        :assign, :reassign,
+        :unassign, :remove_assignee,
+        :milestone,
+        :remove_milestone,
+        :clear_milestone,
+        :labels, :label,
+        :unlabel, :remove_labels, :remove_label,
+        :clear_labels, :clear_label,
+        :todo,
+        :done,
+        :subscribe,
+        :unsubscribe,
+        :due_date,
+        :clear_due_date
+      ])
+    end
+  end
+
+  describe '#execute' do
+    let(:service) { described_class.new(project, user) }
+
+    shared_examples 'open command' do
+      it 'returns state_event: "open" if content contains /open' do
+        changes = service.execute(content)
+
+        expect(changes).to eq(state_event: 'reopen')
+      end
+    end
+
+    shared_examples 'close command' do
+      it 'returns state_event: "close" if content contains /open' do
+        changes = service.execute(content)
+
+        expect(changes).to eq(state_event: 'close')
+      end
+    end
+
+    shared_examples 'assign command' do
+      it 'fetches assignee and populates assignee_id if content contains /assign' do
+        changes = service.execute(content)
+
+        expect(changes).to eq(assignee_id: user.id)
+      end
+    end
+
+    shared_examples 'milestone command' do
+      it 'fetches milestone and populates milestone_id if content contains /milestone' do
+        changes = service.execute(content)
+
+        expect(changes).to eq(milestone_id: milestone.id)
+      end
+    end
+
+    shared_examples 'label command' do
+      it 'fetches label ids and populates add_label_ids if content contains /label' do
+        changes = service.execute(content)
+
+        expect(changes).to eq(add_label_ids: [bug.id, inprogress.id])
+      end
+    end
+
+    shared_examples 'remove_labels command' do
+      it 'fetches label ids and populates remove_label_ids if content contains /label' do
+        changes = service.execute(content)
+
+        expect(changes).to eq(remove_label_ids: [inprogress.id])
+      end
+    end
+
+    shared_examples 'clear_labels command' do
+      it 'populates label_ids: [] if content contains /clear_labels' do
+        changes = service.execute(content)
+
+        expect(changes).to eq(label_ids: [])
+      end
+    end
+
+    shared_examples 'command returning no changes' do
+      it 'returns an empty hash if content contains /open' do
+        changes = service.execute(content)
+
+        expect(changes).to be_empty
+      end
+    end
+
+    it_behaves_like 'open command' do
+      let(:content) { '/open' }
+    end
+
+    it_behaves_like 'open command' do
+      let(:content) { '/reopen' }
+    end
+
+    it_behaves_like 'close command' do
+      let(:content) { '/close' }
+    end
+
+    it_behaves_like 'assign command' do
+      let(:content) { "/assign @#{user.username}" }
+    end
+
+    it 'does not populate assignee_id if content contains /assign with an unknown user' do
+      changes = service.execute('/assign joe')
+
+      expect(changes).to be_empty
+    end
+
+    it 'does not populate assignee_id if content contains /assign without user' do
+      changes = service.execute('/assign')
+
+      expect(changes).to be_empty
+    end
+
+    it 'populates assignee_id: nil if content contains /unassign' do
+      changes = service.execute('/unassign')
+
+      expect(changes).to eq(assignee_id: nil)
+    end
+
+    it_behaves_like 'milestone command' do
+      let(:content) { "/milestone %#{milestone.title}" }
+    end
+
+    it 'populates milestone_id: nil if content contains /clear_milestone' do
+      changes = service.execute('/clear_milestone')
+
+      expect(changes).to eq(milestone_id: nil)
+    end
+
+    it_behaves_like 'label command' do
+      let(:content) { %(/label ~"#{inprogress.title}" ~#{bug.title} ~unknown) }
+    end
+
+    it_behaves_like 'label command' do
+      let(:content) { %(/labels ~"#{inprogress.title}" ~#{bug.title} ~unknown) }
+    end
+
+    it_behaves_like 'remove_labels command' do
+      let(:content) { %(/unlabel ~"#{inprogress.title}") }
+    end
+
+    it_behaves_like 'remove_labels command' do
+      let(:content) { %(/remove_labels ~"#{inprogress.title}") }
+    end
+
+    it_behaves_like 'remove_labels command' do
+      let(:content) { %(/remove_label ~"#{inprogress.title}") }
+    end
+
+    it_behaves_like 'clear_labels command' do
+      let(:content) { '/clear_labels' }
+    end
+
+    it_behaves_like 'clear_labels command' do
+      let(:content) { '/clear_label' }
+    end
+
+    it 'populates todo: :mark if content contains /todo' do
+      changes = service.execute('/todo')
+
+      expect(changes).to eq(todo_event: 'mark')
+    end
+
+    it 'populates todo: :done if content contains /done' do
+      changes = service.execute('/done')
+
+      expect(changes).to eq(todo_event: 'done')
+    end
+
+    it 'populates subscription: :subscribe if content contains /subscribe' do
+      changes = service.execute('/subscribe')
+
+      expect(changes).to eq(subscription_event: 'subscribe')
+    end
+
+    it 'populates subscription: :unsubscribe if content contains /unsubscribe' do
+      changes = service.execute('/unsubscribe')
+
+      expect(changes).to eq(subscription_event: 'unsubscribe')
+    end
+
+    it 'populates due_date: Time.now.tomorrow if content contains /due_date 2016-08-28' do
+      changes = service.execute('/due_date 2016-08-28')
+
+      expect(changes).to eq(due_date: Date.new(2016, 8, 28))
+    end
+
+    it 'populates due_date: Time.now.tomorrow if content contains /due_date foo' do
+      changes = service.execute('/due_date foo')
+
+      expect(changes).to be_empty
+    end
+
+    it 'populates due_date: nil if content contains /clear_due_date' do
+      changes = service.execute('/clear_due_date')
+
+      expect(changes).to eq(due_date: nil)
+    end
+  end
+end
diff --git a/spec/support/issuable_create_service_slash_commands_shared_examples.rb b/spec/support/issuable_create_service_slash_commands_shared_examples.rb
new file mode 100644
index 00000000000..bd0201c866f
--- /dev/null
+++ b/spec/support/issuable_create_service_slash_commands_shared_examples.rb
@@ -0,0 +1,83 @@
+# Specifications for behavior common to all objects with executable attributes.
+# It can take a `default_params`.
+
+shared_examples 'new issuable record that supports slash commands' do
+  let!(:project) { create(:project) }
+  let(:user) { create(:user).tap { |u| project.team << [u, :master] } }
+  let(:assignee) { create(:user) }
+  let!(:milestone) { create(:milestone, project: project) }
+  let!(:labels) { create_list(:label, 3, project: project) }
+  let(:base_params) { { title: FFaker::Lorem.sentence(3) } }
+  let(:params) { base_params.merge(defined?(default_params) ? default_params : {}).merge(example_params) }
+  let(:issuable) { described_class.new(project, user, params).execute }
+
+  context 'with labels in command only' do
+    let(:example_params) do
+      {
+        description: "/label ~#{labels.first.name} ~#{labels.second.name}\n/remove_label ~#{labels.third.name}"
+      }
+    end
+
+    it 'attaches labels to issuable' do
+      expect(issuable).to be_persisted
+      expect(issuable.label_ids).to match_array([labels.first.id, labels.second.id])
+    end
+  end
+
+  context 'with labels in params and command' do
+    let(:example_params) do
+      {
+        label_ids: [labels.second.id],
+        description: "/label ~#{labels.first.name}\n/remove_label ~#{labels.third.name}"
+      }
+    end
+
+    it 'attaches all labels to issuable' do
+      expect(issuable).to be_persisted
+      expect(issuable.label_ids).to match_array([labels.first.id, labels.second.id])
+    end
+  end
+
+  context 'with assignee and milestone in command only' do
+    let(:example_params) do
+      {
+        description: %(/assign @#{assignee.username}\n/milestone %"#{milestone.name}")
+      }
+    end
+
+    it 'assigns and sets milestone to issuable' do
+      expect(issuable).to be_persisted
+      expect(issuable.assignee).to eq(assignee)
+      expect(issuable.milestone).to eq(milestone)
+    end
+  end
+
+  context 'with assignee and milestone in params and command' do
+    let(:example_params) do
+      {
+        assignee: build_stubbed(:user),
+        milestone_id: double(:milestone),
+        description: %(/assign @#{assignee.username}\n/milestone %"#{milestone.name}")
+      }
+    end
+
+    it 'assigns and sets milestone to issuable from command' do
+      expect(issuable).to be_persisted
+      expect(issuable.assignee).to eq(assignee)
+      expect(issuable.milestone).to eq(milestone)
+    end
+  end
+
+  describe '/close' do
+    let(:example_params) do
+      {
+        description: '/close'
+      }
+    end
+
+    it 'returns an open issue' do
+      expect(issuable).to be_persisted
+      expect(issuable).to be_open
+    end
+  end
+end
diff --git a/spec/support/issuable_slash_commands_shared_examples.rb b/spec/support/issuable_slash_commands_shared_examples.rb
new file mode 100644
index 00000000000..0c8bd69add6
--- /dev/null
+++ b/spec/support/issuable_slash_commands_shared_examples.rb
@@ -0,0 +1,170 @@
+# Specifications for behavior common to all objects with executable attributes.
+# It takes a `issuable_type`, and expect an `issuable`.
+
+shared_examples 'issuable record that supports slash commands in its description and notes' do |issuable_type|
+  let(:user) { create(:user) }
+  let(:assignee) { create(:user, username: 'bob') }
+  let(:project) { create(:project, :public) }
+  let!(:milestone) { create(:milestone, project: project, title: 'ASAP') }
+  let!(:label_bug) { create(:label, project: project, title: 'bug') }
+  let!(:label_feature) { create(:label, project: project, title: 'feature') }
+  let(:new_url_opts) { {} }
+
+  before do
+    project.team << [user, :master]
+    project.team << [assignee, :developer]
+    login_with(user)
+  end
+
+  describe "new #{issuable_type}" do
+    context 'with commands in the description' do
+      it "creates the #{issuable_type} and interpret commands accordingly" do
+        visit public_send("new_namespace_project_#{issuable_type}_path", project.namespace, project, new_url_opts)
+        fill_in "#{issuable_type}_title", with: 'bug 345'
+        fill_in "#{issuable_type}_description", with: "bug description\n/label ~bug\n/milestone %\"ASAP\""
+        click_button "Submit #{issuable_type}".humanize
+
+        issuable = project.public_send(issuable_type.to_s.pluralize).first
+
+        expect(issuable.description).to eq "bug description\r\n"
+        expect(issuable.labels).to eq [label_bug]
+        expect(issuable.milestone).to eq milestone
+        expect(page).to have_content 'bug 345'
+        expect(page).to have_content 'bug description'
+      end
+    end
+  end
+
+  describe "note on #{issuable_type}" do
+    before do
+      visit public_send("namespace_project_#{issuable_type}_path", project.namespace, project, issuable)
+    end
+
+    context 'with a note containing commands' do
+      it 'creates a note without the commands and interpret the commands accordingly' do
+        page.within('.js-main-target-form') do
+          fill_in 'note[note]', with: "Awesome!\n/assign @bob\n/label ~bug\n/milestone %\"ASAP\""
+          click_button 'Comment'
+        end
+
+        expect(page).to have_content 'Awesome!'
+        expect(page).not_to have_content '/assign @bob'
+        expect(page).not_to have_content '/label ~bug'
+        expect(page).not_to have_content '/milestone %"ASAP"'
+
+        issuable.reload
+        note = issuable.notes.user.first
+
+        expect(note.note).to eq "Awesome!\r\n"
+        expect(issuable.assignee).to eq assignee
+        expect(issuable.labels).to eq [label_bug]
+        expect(issuable.milestone).to eq milestone
+      end
+    end
+
+    context 'with a note containing only commands' do
+      it 'does not create a note but interpret the commands accordingly' do
+        page.within('.js-main-target-form') do
+          fill_in 'note[note]', with: "/assign @bob\n/label ~bug\n/milestone %\"ASAP\""
+          click_button 'Comment'
+        end
+
+        expect(page).not_to have_content '/assign @bob'
+        expect(page).not_to have_content '/label ~bug'
+        expect(page).not_to have_content '/milestone %"ASAP"'
+        expect(page).to have_content 'Your commands are being executed.'
+
+        issuable.reload
+
+        expect(issuable.notes.user).to be_empty
+        expect(issuable.assignee).to eq assignee
+        expect(issuable.labels).to eq [label_bug]
+        expect(issuable.milestone).to eq milestone
+      end
+    end
+
+    context "with a note marking the #{issuable_type} as todo" do
+      it "creates a new todo for the #{issuable_type}" do
+        page.within('.js-main-target-form') do
+          fill_in 'note[note]', with: "/todo"
+          click_button 'Comment'
+        end
+
+        expect(page).not_to have_content '/todo'
+        expect(page).to have_content 'Your commands are being executed.'
+
+        todos = TodosFinder.new(user).execute
+        todo = todos.first
+
+        expect(todos.size).to eq 1
+        expect(todo).to be_pending
+        expect(todo.target).to eq issuable
+        expect(todo.author).to eq user
+        expect(todo.user).to eq user
+      end
+    end
+
+    context "with a note marking the #{issuable_type} as done" do
+      before do
+        TodoService.new.mark_todo(issuable, user)
+      end
+
+      it "creates a new todo for the #{issuable_type}" do
+        todos = TodosFinder.new(user).execute
+        todo = todos.first
+
+        expect(todos.size).to eq 1
+        expect(todos.first).to be_pending
+        expect(todo.target).to eq issuable
+        expect(todo.author).to eq user
+        expect(todo.user).to eq user
+
+        page.within('.js-main-target-form') do
+          fill_in 'note[note]', with: "/done"
+          click_button 'Comment'
+        end
+
+        expect(page).not_to have_content '/done'
+        expect(page).to have_content 'Your commands are being executed.'
+
+        expect(todo.reload).to be_done
+      end
+    end
+
+    context "with a note subscribing to the #{issuable_type}" do
+      it "creates a new todo for the #{issuable_type}" do
+        expect(issuable.subscribed?(user)).to be_falsy
+
+        page.within('.js-main-target-form') do
+          fill_in 'note[note]', with: "/subscribe"
+          click_button 'Comment'
+        end
+
+        expect(page).not_to have_content '/subscribe'
+        expect(page).to have_content 'Your commands are being executed.'
+
+        expect(issuable.subscribed?(user)).to be_truthy
+      end
+    end
+
+    context "with a note unsubscribing to the #{issuable_type} as done" do
+      before do
+        issuable.subscribe(user)
+      end
+
+      it "creates a new todo for the #{issuable_type}" do
+        expect(issuable.subscribed?(user)).to be_truthy
+
+        page.within('.js-main-target-form') do
+          fill_in 'note[note]', with: "/unsubscribe"
+          click_button 'Comment'
+        end
+
+        expect(page).not_to have_content '/unsubscribe'
+        expect(page).to have_content 'Your commands are being executed.'
+
+        expect(issuable.subscribed?(user)).to be_falsy
+      end
+    end
+  end
+end
diff --git a/spec/support/note_create_service_slash_commands_shared_examples.rb b/spec/support/note_create_service_slash_commands_shared_examples.rb
new file mode 100644
index 00000000000..3f7ad8b2f91
--- /dev/null
+++ b/spec/support/note_create_service_slash_commands_shared_examples.rb
@@ -0,0 +1,116 @@
+# Specifications for behavior common to all note objects with executable attributes.
+# It expects a `noteable` object for which the note is posted.
+
+shared_context 'note on noteable' do
+  let!(:project) { create(:project) }
+  let(:user) { create(:user).tap { |u| project.team << [u, :master] } }
+  let(:assignee) { create(:user) }
+  let(:base_params) { { noteable: noteable } }
+  let(:params) { base_params.merge(example_params) }
+  let(:note) { described_class.new(project, user, params).execute }
+end
+
+shared_examples 'note on noteable that does not support slash commands' do
+  include_context 'note on noteable'
+
+  let(:params) { { commit_id: noteable.id, noteable_type: 'Commit' }.merge(example_params) }
+
+  describe 'note with only command' do
+    describe '/close, /label, /assign & /milestone' do
+      let(:note_text) { %(/close\n/assign @#{assignee.username}") }
+      let(:example_params) { { note: note_text } }
+
+      it 'saves the note and does not alter the note text' do
+        expect(note).to be_persisted
+        expect(note.note).to eq note_text
+      end
+    end
+  end
+
+  describe 'note with command & text' do
+    describe '/close, /label, /assign & /milestone' do
+      let(:note_text) { %(HELLO\n/close\n/assign @#{assignee.username}\nWORLD) }
+      let(:example_params) { { note: note_text } }
+
+      it 'saves the note and does not alter the note text' do
+        expect(note).to be_persisted
+        expect(note.note).to eq note_text
+      end
+    end
+  end
+end
+
+shared_examples 'note on noteable that supports slash commands' do
+  include_context 'note on noteable'
+
+  let!(:milestone) { create(:milestone, project: project) }
+  let!(:labels) { create_pair(:label, project: project) }
+
+  describe 'note with only command' do
+    describe '/close, /label, /assign & /milestone' do
+      let(:example_params) do
+        {
+          note: %(/close\n/label ~#{labels.first.name} ~#{labels.last.name}\n/assign @#{assignee.username}\n/milestone %"#{milestone.name}")
+        }
+      end
+
+      it 'closes noteable, sets labels, assigns, and sets milestone to noteable, and leave no note' do
+        expect(note).not_to be_persisted
+        expect(note.note).to eq ''
+        expect(noteable).to be_closed
+        expect(noteable.labels).to match_array(labels)
+        expect(noteable.assignee).to eq(assignee)
+        expect(noteable.milestone).to eq(milestone)
+      end
+    end
+
+    describe '/open' do
+      let(:noteable) { create(:issue, project: project, state: :closed) }
+      let(:example_params) do
+        {
+          note: '/open'
+        }
+      end
+
+      it 'opens the noteable, and leave no note' do
+        expect(note).not_to be_persisted
+        expect(note.note).to eq ''
+        expect(noteable).to be_open
+      end
+    end
+  end
+
+  describe 'note with command & text' do
+    describe '/close, /label, /assign & /milestone' do
+      let(:example_params) do
+        {
+          note: %(HELLO\n/close\n/label ~#{labels.first.name} ~#{labels.last.name}\n/assign @#{assignee.username}\n/milestone %"#{milestone.name}"\nWORLD)
+        }
+      end
+
+      it 'closes noteable, sets labels, assigns, and sets milestone to noteable' do
+        expect(note).to be_persisted
+        expect(note.note).to eq "HELLO\nWORLD"
+        expect(noteable).to be_closed
+        expect(noteable.labels).to match_array(labels)
+        expect(noteable.assignee).to eq(assignee)
+        expect(noteable.milestone).to eq(milestone)
+      end
+    end
+
+    describe '/open' do
+      let(:noteable) { create(:issue, project: project, state: :closed) }
+      let(:example_params) do
+        {
+          note: "HELLO\n/open\nWORLD"
+        }
+      end
+
+      it 'opens the noteable' do
+        expect(note).to be_persisted
+        expect(note.note).to eq "HELLO\nWORLD"
+        expect(noteable).to be_open
+      end
+    end
+  end
+end

From a54fdc384fee9daeab1b9fb638dae5dce4e4be15 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Coutable?= <remy@rymai.me>
Date: Tue, 9 Aug 2016 17:51:40 +0200
Subject: [PATCH 02/25] Enforce permissions in
 `{Issues,MergeRequests}::{Close,Reopen}Service`
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Rémy Coutable <remy@rymai.me>
---
 app/services/issues/close_service.rb          |   2 +
 app/services/issues/reopen_service.rb         |   2 +
 app/services/merge_requests/close_service.rb  |   2 +
 app/services/merge_requests/reopen_service.rb |   2 +
 spec/services/issues/close_service_spec.rb    |  18 ++-
 spec/services/issues/reopen_service_spec.rb   |  25 ++++
 .../merge_requests/close_service_spec.rb      |  16 ++-
 .../merge_requests/reopen_service_spec.rb     |  19 ++-
 ...issuable_slash_commands_shared_examples.rb | 113 +++++++++++++++---
 9 files changed, 178 insertions(+), 21 deletions(-)
 create mode 100644 spec/services/issues/reopen_service_spec.rb

diff --git a/app/services/issues/close_service.rb b/app/services/issues/close_service.rb
index 859c934ea3b..45cca216ccc 100644
--- a/app/services/issues/close_service.rb
+++ b/app/services/issues/close_service.rb
@@ -1,6 +1,8 @@
 module Issues
   class CloseService < Issues::BaseService
     def execute(issue, commit: nil, notifications: true, system_note: true)
+      return issue unless can?(current_user, :update_issue, issue)
+
       if project.jira_tracker? && project.jira_service.active
         project.jira_service.execute(commit, issue)
         todo_service.close_issue(issue, current_user)
diff --git a/app/services/issues/reopen_service.rb b/app/services/issues/reopen_service.rb
index e48ca359f4f..40fbe354492 100644
--- a/app/services/issues/reopen_service.rb
+++ b/app/services/issues/reopen_service.rb
@@ -1,6 +1,8 @@
 module Issues
   class ReopenService < Issues::BaseService
     def execute(issue)
+      return issue unless can?(current_user, :update_issue, issue)
+
       if issue.reopen
         event_service.reopen_issue(issue, current_user)
         create_note(issue)
diff --git a/app/services/merge_requests/close_service.rb b/app/services/merge_requests/close_service.rb
index 27ee81fe3e7..f2053bda83a 100644
--- a/app/services/merge_requests/close_service.rb
+++ b/app/services/merge_requests/close_service.rb
@@ -1,6 +1,8 @@
 module MergeRequests
   class CloseService < MergeRequests::BaseService
     def execute(merge_request, commit = nil)
+      return merge_request unless can?(current_user, :update_merge_request, merge_request)
+
       # If we close MergeRequest we want to ignore validation
       # so we can close broken one (Ex. fork project removed)
       merge_request.allow_broken = true
diff --git a/app/services/merge_requests/reopen_service.rb b/app/services/merge_requests/reopen_service.rb
index eb88ae9d11c..fadcce5d9b6 100644
--- a/app/services/merge_requests/reopen_service.rb
+++ b/app/services/merge_requests/reopen_service.rb
@@ -1,6 +1,8 @@
 module MergeRequests
   class ReopenService < MergeRequests::BaseService
     def execute(merge_request)
+      return merge_request unless can?(current_user, :update_merge_request, merge_request)
+
       if merge_request.reopen
         event_service.reopen_mr(merge_request, current_user)
         create_note(merge_request)
diff --git a/spec/services/issues/close_service_spec.rb b/spec/services/issues/close_service_spec.rb
index 1318607a388..aff022a573e 100644
--- a/spec/services/issues/close_service_spec.rb
+++ b/spec/services/issues/close_service_spec.rb
@@ -3,6 +3,7 @@ require 'spec_helper'
 describe Issues::CloseService, services: true do
   let(:user) { create(:user) }
   let(:user2) { create(:user) }
+  let(:guest) { create(:user) }
   let(:issue) { create(:issue, assignee: user2) }
   let(:project) { issue.project }
   let!(:todo) { create(:todo, :assigned, user: user, project: project, target: issue, author: user2) }
@@ -10,13 +11,14 @@ describe Issues::CloseService, services: true do
   before do
     project.team << [user, :master]
     project.team << [user2, :developer]
+    project.team << [guest, :guest]
   end
 
   describe '#execute' do
     context "valid params" do
       before do
         perform_enqueued_jobs do
-          @issue = Issues::CloseService.new(project, user, {}).execute(issue)
+          @issue = described_class.new(project, user, {}).execute(issue)
         end
       end
 
@@ -39,10 +41,22 @@ describe Issues::CloseService, services: true do
       end
     end
 
+    context 'current user is not authorized to close issue' do
+      before do
+        perform_enqueued_jobs do
+          @issue = described_class.new(project, guest).execute(issue)
+        end
+      end
+
+      it 'does not close the issue' do
+        expect(@issue).to be_open
+      end
+    end
+
     context "external issue tracker" do
       before do
         allow(project).to receive(:default_issues_tracker?).and_return(false)
-        @issue = Issues::CloseService.new(project, user, {}).execute(issue)
+        @issue = described_class.new(project, user, {}).execute(issue)
       end
 
       it { expect(@issue).to be_valid }
diff --git a/spec/services/issues/reopen_service_spec.rb b/spec/services/issues/reopen_service_spec.rb
new file mode 100644
index 00000000000..34a89fcd4e1
--- /dev/null
+++ b/spec/services/issues/reopen_service_spec.rb
@@ -0,0 +1,25 @@
+require 'spec_helper'
+
+describe Issues::ReopenService, services: true do
+  let(:guest) { create(:user) }
+  let(:issue) { create(:issue, :closed) }
+  let(:project) { issue.project }
+
+  before do
+    project.team << [guest, :guest]
+  end
+
+  describe '#execute' do
+    context 'current user is not authorized to reopen issue' do
+      before do
+        perform_enqueued_jobs do
+          @issue = described_class.new(project, guest).execute(issue)
+        end
+      end
+
+      it 'does not reopen the issue' do
+        expect(@issue).to be_closed
+      end
+    end
+  end
+end
diff --git a/spec/services/merge_requests/close_service_spec.rb b/spec/services/merge_requests/close_service_spec.rb
index 403533be5d9..24c25e4350f 100644
--- a/spec/services/merge_requests/close_service_spec.rb
+++ b/spec/services/merge_requests/close_service_spec.rb
@@ -3,6 +3,7 @@ require 'spec_helper'
 describe MergeRequests::CloseService, services: true do
   let(:user) { create(:user) }
   let(:user2) { create(:user) }
+  let(:guest) { create(:user) }
   let(:merge_request) { create(:merge_request, assignee: user2) }
   let(:project) { merge_request.project }
   let!(:todo) { create(:todo, :assigned, user: user, project: project, target: merge_request, author: user2) }
@@ -10,11 +11,12 @@ describe MergeRequests::CloseService, services: true do
   before do
     project.team << [user, :master]
     project.team << [user2, :developer]
+    project.team << [guest, :guest]
   end
 
   describe '#execute' do
     context 'valid params' do
-      let(:service) { MergeRequests::CloseService.new(project, user, {}) }
+      let(:service) { described_class.new(project, user, {}) }
 
       before do
         allow(service).to receive(:execute_hooks)
@@ -47,5 +49,17 @@ describe MergeRequests::CloseService, services: true do
         expect(todo.reload).to be_done
       end
     end
+
+    context 'current user is not authorized to close merge request' do
+      before do
+        perform_enqueued_jobs do
+          @merge_request = described_class.new(project, guest).execute(merge_request)
+        end
+      end
+
+      it 'does not close the merge request' do
+        expect(@merge_request).to be_open
+      end
+    end
   end
 end
diff --git a/spec/services/merge_requests/reopen_service_spec.rb b/spec/services/merge_requests/reopen_service_spec.rb
index 3419b8bf5e6..af7424a76a9 100644
--- a/spec/services/merge_requests/reopen_service_spec.rb
+++ b/spec/services/merge_requests/reopen_service_spec.rb
@@ -3,22 +3,23 @@ require 'spec_helper'
 describe MergeRequests::ReopenService, services: true do
   let(:user) { create(:user) }
   let(:user2) { create(:user) }
-  let(:merge_request) { create(:merge_request, assignee: user2) }
+  let(:guest) { create(:user) }
+  let(:merge_request) { create(:merge_request, :closed, assignee: user2) }
   let(:project) { merge_request.project }
 
   before do
     project.team << [user, :master]
     project.team << [user2, :developer]
+    project.team << [guest, :guest]
   end
 
   describe '#execute' do
     context 'valid params' do
-      let(:service) { MergeRequests::ReopenService.new(project, user, {}) }
+      let(:service) { described_class.new(project, user, {}) }
 
       before do
         allow(service).to receive(:execute_hooks)
 
-        merge_request.state = :closed
         perform_enqueued_jobs do
           service.execute(merge_request)
         end
@@ -43,5 +44,17 @@ describe MergeRequests::ReopenService, services: true do
         expect(note.note).to include 'Status changed to reopened'
       end
     end
+
+    context 'current user is not authorized to reopen merge request' do
+      before do
+        perform_enqueued_jobs do
+          @merge_request = described_class.new(project, guest).execute(merge_request)
+        end
+      end
+
+      it 'does not reopen the merge request' do
+        expect(@merge_request).to be_closed
+      end
+    end
   end
 end
diff --git a/spec/support/issuable_slash_commands_shared_examples.rb b/spec/support/issuable_slash_commands_shared_examples.rb
index 0c8bd69add6..3b8783cb053 100644
--- a/spec/support/issuable_slash_commands_shared_examples.rb
+++ b/spec/support/issuable_slash_commands_shared_examples.rb
@@ -2,8 +2,9 @@
 # It takes a `issuable_type`, and expect an `issuable`.
 
 shared_examples 'issuable record that supports slash commands in its description and notes' do |issuable_type|
-  let(:user) { create(:user) }
+  let(:master) { create(:user) }
   let(:assignee) { create(:user, username: 'bob') }
+  let(:guest) { create(:user) }
   let(:project) { create(:project, :public) }
   let!(:milestone) { create(:milestone, project: project, title: 'ASAP') }
   let!(:label_bug) { create(:label, project: project, title: 'bug') }
@@ -11,9 +12,10 @@ shared_examples 'issuable record that supports slash commands in its description
   let(:new_url_opts) { {} }
 
   before do
-    project.team << [user, :master]
+    project.team << [master, :master]
     project.team << [assignee, :developer]
-    login_with(user)
+    project.team << [guest, :guest]
+    login_with(master)
   end
 
   describe "new #{issuable_type}" do
@@ -83,6 +85,87 @@ shared_examples 'issuable record that supports slash commands in its description
       end
     end
 
+    context "with a note closing the #{issuable_type}" do
+      before do
+        expect(issuable).to be_open
+      end
+
+      context "when current user can close #{issuable_type}" do
+        it "closes the #{issuable_type}" do
+          page.within('.js-main-target-form') do
+            fill_in 'note[note]', with: "/close"
+            click_button 'Comment'
+          end
+
+          expect(page).not_to have_content '/close'
+          expect(page).to have_content 'Your commands are being executed.'
+
+          expect(issuable.reload).to be_closed
+        end
+      end
+
+      context "when current user cannot close #{issuable_type}" do
+        before do
+          logout
+          login_with(guest)
+          visit public_send("namespace_project_#{issuable_type}_path", project.namespace, project, issuable)
+        end
+
+        it "does not close the #{issuable_type}" do
+          page.within('.js-main-target-form') do
+            fill_in 'note[note]', with: "/close"
+            click_button 'Comment'
+          end
+
+          expect(page).not_to have_content '/close'
+          expect(page).to have_content 'Your commands are being executed.'
+
+          expect(issuable).to be_open
+        end
+      end
+    end
+
+    context "with a note reopening the #{issuable_type}" do
+      before do
+        issuable.close
+        expect(issuable).to be_closed
+      end
+
+      context "when current user can reopen #{issuable_type}" do
+        it "reopens the #{issuable_type}" do
+          page.within('.js-main-target-form') do
+            fill_in 'note[note]', with: "/reopen"
+            click_button 'Comment'
+          end
+
+          expect(page).not_to have_content '/reopen'
+          expect(page).to have_content 'Your commands are being executed.'
+
+          expect(issuable.reload).to be_open
+        end
+      end
+
+      context "when current user cannot reopen #{issuable_type}" do
+        before do
+          logout
+          login_with(guest)
+          visit public_send("namespace_project_#{issuable_type}_path", project.namespace, project, issuable)
+        end
+
+        it "does not reopen the #{issuable_type}" do
+          page.within('.js-main-target-form') do
+            fill_in 'note[note]', with: "/reopen"
+            click_button 'Comment'
+          end
+
+          expect(page).not_to have_content '/reopen'
+          expect(page).to have_content 'Your commands are being executed.'
+
+          expect(issuable).to be_closed
+        end
+      end
+    end
+
     context "with a note marking the #{issuable_type} as todo" do
       it "creates a new todo for the #{issuable_type}" do
         page.within('.js-main-target-form') do
@@ -93,31 +176,31 @@ shared_examples 'issuable record that supports slash commands in its description
         expect(page).not_to have_content '/todo'
         expect(page).to have_content 'Your commands are being executed.'
 
-        todos = TodosFinder.new(user).execute
+        todos = TodosFinder.new(master).execute
         todo = todos.first
 
         expect(todos.size).to eq 1
         expect(todo).to be_pending
         expect(todo.target).to eq issuable
-        expect(todo.author).to eq user
-        expect(todo.user).to eq user
+        expect(todo.author).to eq master
+        expect(todo.user).to eq master
       end
     end
 
     context "with a note marking the #{issuable_type} as done" do
       before do
-        TodoService.new.mark_todo(issuable, user)
+        TodoService.new.mark_todo(issuable, master)
       end
 
       it "creates a new todo for the #{issuable_type}" do
-        todos = TodosFinder.new(user).execute
+        todos = TodosFinder.new(master).execute
         todo = todos.first
 
         expect(todos.size).to eq 1
         expect(todos.first).to be_pending
         expect(todo.target).to eq issuable
-        expect(todo.author).to eq user
-        expect(todo.user).to eq user
+        expect(todo.author).to eq master
+        expect(todo.user).to eq master
 
         page.within('.js-main-target-form') do
           fill_in 'note[note]', with: "/done"
@@ -133,7 +216,7 @@ shared_examples 'issuable record that supports slash commands in its description
 
     context "with a note subscribing to the #{issuable_type}" do
       it "creates a new todo for the #{issuable_type}" do
-        expect(issuable.subscribed?(user)).to be_falsy
+        expect(issuable.subscribed?(master)).to be_falsy
 
         page.within('.js-main-target-form') do
           fill_in 'note[note]', with: "/subscribe"
@@ -143,17 +226,17 @@ shared_examples 'issuable record that supports slash commands in its description
         expect(page).not_to have_content '/subscribe'
         expect(page).to have_content 'Your commands are being executed.'
 
-        expect(issuable.subscribed?(user)).to be_truthy
+        expect(issuable.subscribed?(master)).to be_truthy
       end
     end
 
     context "with a note unsubscribing to the #{issuable_type} as done" do
       before do
-        issuable.subscribe(user)
+        issuable.subscribe(master)
       end
 
       it "creates a new todo for the #{issuable_type}" do
-        expect(issuable.subscribed?(user)).to be_truthy
+        expect(issuable.subscribed?(master)).to be_truthy
 
         page.within('.js-main-target-form') do
           fill_in 'note[note]', with: "/unsubscribe"
@@ -163,7 +246,7 @@ shared_examples 'issuable record that supports slash commands in its description
         expect(page).not_to have_content '/unsubscribe'
         expect(page).to have_content 'Your commands are being executed.'
 
-        expect(issuable.subscribed?(user)).to be_falsy
+        expect(issuable.subscribed?(master)).to be_falsy
       end
     end
   end

From 7cc4ab14b8a2f1d7d374a320b79374764527659f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Coutable?= <remy@rymai.me>
Date: Tue, 9 Aug 2016 19:26:45 +0200
Subject: [PATCH 03/25] New Notes::SlashCommandsService service
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Check for update_issuable permission in Notes::SlashCommandsService

Signed-off-by: Rémy Coutable <remy@rymai.me>
---
 app/services/issuable_base_service.rb         |  18 +-
 app/services/notes/create_service.rb          |  43 +--
 app/services/notes/slash_commands_service.rb  |  22 ++
 .../slash_commands/interpret_service.rb       |   9 +-
 .../user_uses_slash_commands_spec.rb          |  27 --
 spec/services/notes/create_service_spec.rb    |  23 +-
 .../notes/slash_commands_service_spec.rb      | 129 +++++++++
 .../slash_commands/interpret_service_spec.rb  | 257 ++++++++++++++----
 ...issuable_slash_commands_shared_examples.rb |   4 +-
 ..._service_slash_commands_shared_examples.rb | 116 --------
 10 files changed, 392 insertions(+), 256 deletions(-)
 create mode 100644 app/services/notes/slash_commands_service.rb
 create mode 100644 spec/services/notes/slash_commands_service_spec.rb
 delete mode 100644 spec/support/note_create_service_slash_commands_shared_examples.rb

diff --git a/app/services/issuable_base_service.rb b/app/services/issuable_base_service.rb
index b365e19c4a8..3512e2b735e 100644
--- a/app/services/issuable_base_service.rb
+++ b/app/services/issuable_base_service.rb
@@ -81,21 +81,21 @@ class IssuableBaseService < BaseService
   end
 
   def process_label_ids(attributes, base_label_ids: [], merge_all: false)
-    label_ids = attributes.delete(:label_ids) { [] }
-    add_label_ids = attributes.delete(:add_label_ids) { [] }
-    remove_label_ids = attributes.delete(:remove_label_ids) { [] }
+    label_ids = attributes.delete(:label_ids)
+    add_label_ids = attributes.delete(:add_label_ids)
+    remove_label_ids = attributes.delete(:remove_label_ids)
 
     new_label_ids = base_label_ids
-    new_label_ids |= label_ids if merge_all || (add_label_ids.empty? && remove_label_ids.empty?)
-    new_label_ids |= add_label_ids
-    new_label_ids -= remove_label_ids
+    new_label_ids = label_ids if label_ids && (merge_all || (add_label_ids.empty? && remove_label_ids.empty?))
+    new_label_ids |= add_label_ids if add_label_ids
+    new_label_ids -= remove_label_ids if remove_label_ids
 
     new_label_ids
   end
 
-  def merge_slash_commands_into_params!
+  def merge_slash_commands_into_params!(issuable)
     command_params = SlashCommands::InterpretService.new(project, current_user).
-      execute(params[:description])
+      execute(params[:description], issuable)
 
     params.merge!(command_params)
   end
@@ -115,7 +115,7 @@ class IssuableBaseService < BaseService
   end
 
   def create(issuable)
-    merge_slash_commands_into_params!
+    merge_slash_commands_into_params!(issuable)
     filter_params
 
     if params.present? && create_issuable(issuable, params)
diff --git a/app/services/notes/create_service.rb b/app/services/notes/create_service.rb
index d7531a5d63b..0c2513409a1 100644
--- a/app/services/notes/create_service.rb
+++ b/app/services/notes/create_service.rb
@@ -14,7 +14,7 @@ module Notes
       # We execute commands (extracted from `params[:note]`) on the noteable
       # **before** we save the note because if the note consists of commands
       # only, there is no need be create a note!
-      commands_executed = execute_slash_commands!(note)
+      commands_executed = SlashCommandsService.new(project, current_user).execute(note)
 
       if note.save
         # Finish the harder work in the background
@@ -22,50 +22,13 @@ module Notes
         todo_service.new_note(note, current_user)
       end
 
+      # We must add the error after we call #save because errors are reset
+      # when #save is called
       if commands_executed && note.note.blank?
         note.errors.add(:commands_only, 'Your commands are being executed.')
       end
 
       note
     end
-
-    private
-
-    def execute_slash_commands!(note)
-      noteable_update_service = noteable_update_service(note.noteable_type)
-      return unless noteable_update_service
-
-      command_params = SlashCommands::InterpretService.new(project, current_user).
-        execute(note.note)
-
-      commands = execute_or_filter_commands(command_params, note)
-
-      if commands.any?
-        noteable_update_service.new(project, current_user, commands).execute(note.noteable)
-      end
-    end
-
-    def execute_or_filter_commands(commands, note)
-      final_commands = commands.reduce({}) do |memo, (command_key, command_value)|
-        if command_key != :due_date || note.noteable.respond_to?(:due_date)
-          memo[command_key] = command_value
-        end
-
-        memo
-      end
-
-      final_commands
-    end
-
-    def noteable_update_service(noteable_type)
-      case noteable_type
-      when 'Issue'
-        Issues::UpdateService
-      when 'MergeRequest'
-        MergeRequests::UpdateService
-      else
-        nil
-      end
-    end
   end
 end
diff --git a/app/services/notes/slash_commands_service.rb b/app/services/notes/slash_commands_service.rb
new file mode 100644
index 00000000000..54d43d06466
--- /dev/null
+++ b/app/services/notes/slash_commands_service.rb
@@ -0,0 +1,22 @@
+module Notes
+  class SlashCommandsService < BaseService
+
+    UPDATE_SERVICES = {
+      'Issue' => Issues::UpdateService,
+      'MergeRequest' => MergeRequests::UpdateService
+    }
+
+    def execute(note)
+      noteable_update_service = UPDATE_SERVICES[note.noteable_type]
+      return false unless noteable_update_service
+      return false unless can?(current_user, :"update_#{note.noteable_type.underscore}", note.noteable)
+
+      commands = SlashCommands::InterpretService.new(project, current_user).
+        execute(note.note, note.noteable)
+
+      if commands.any?
+        noteable_update_service.new(project, current_user, commands).execute(note.noteable)
+      end
+    end
+  end
+end
diff --git a/app/services/slash_commands/interpret_service.rb b/app/services/slash_commands/interpret_service.rb
index 2c92a4f7de5..bff61683976 100644
--- a/app/services/slash_commands/interpret_service.rb
+++ b/app/services/slash_commands/interpret_service.rb
@@ -2,9 +2,12 @@ module SlashCommands
   class InterpretService < BaseService
     include Gitlab::SlashCommands::Dsl
 
+    attr_reader :noteable
+
     # Takes a text and interpret the commands that are extracted from it.
     # Returns a hash of changes to be applied to a record.
-    def execute(content)
+    def execute(content, noteable)
+      @noteable = noteable
       @updates = {}
 
       commands = extractor.extract_commands!(content)
@@ -105,6 +108,8 @@ module SlashCommands
     desc 'Set a due date'
     params '<YYYY-MM-DD> | <N days>'
     command :due_date do |due_date_param|
+      return unless noteable.respond_to?(:due_date)
+
       due_date = begin
         Time.now + ChronicDuration.parse(due_date_param)
       rescue ChronicDuration::DurationParseError
@@ -116,6 +121,8 @@ module SlashCommands
 
     desc 'Remove due date'
     command :clear_due_date do
+      return unless noteable.respond_to?(:due_date)
+
       @updates[:due_date] = nil
     end
 
diff --git a/spec/features/merge_requests/user_uses_slash_commands_spec.rb b/spec/features/merge_requests/user_uses_slash_commands_spec.rb
index 890648f3860..08c452c6e59 100644
--- a/spec/features/merge_requests/user_uses_slash_commands_spec.rb
+++ b/spec/features/merge_requests/user_uses_slash_commands_spec.rb
@@ -29,31 +29,4 @@ feature 'Merge Requests > User uses slash commands', feature: true, js: true do
       expect(page).not_to have_content '/due_date 2016-08-28'
     end
   end
-
-  # Postponed because of high complexity
-  xdescribe 'merging from note' do
-    before do
-      project.team << [user, :master]
-      login_with(user)
-      visit namespace_project_merge_request_path(project.namespace, project, merge_request)
-    end
-
-    it 'creates a note without the commands and interpret the commands accordingly' do
-      page.within('.js-main-target-form') do
-        fill_in 'note[note]', with: "Let's merge this!\n/merge\n/milestone %ASAP"
-        click_button 'Comment'
-      end
-
-      expect(page).to have_content("Let's merge this!")
-      expect(page).not_to have_content('/merge')
-      expect(page).not_to have_content('/milestone %ASAP')
-
-      merge_request.reload
-      note = merge_request.notes.user.first
-
-      expect(note.note).to eq "Let's merge this!\r\n"
-      expect(merge_request).to be_merged
-      expect(merge_request.milestone).to eq milestone
-    end
-  end
 end
diff --git a/spec/services/notes/create_service_spec.rb b/spec/services/notes/create_service_spec.rb
index 36ca7d2bce8..92dbccf0729 100644
--- a/spec/services/notes/create_service_spec.rb
+++ b/spec/services/notes/create_service_spec.rb
@@ -9,25 +9,30 @@ describe Notes::CreateService, services: true do
   end
 
   describe '#execute' do
+    before do
+      project.team << [user, :master]
+    end
+
     context "valid params" do
       before do
-        project.team << [user, :master]
         @note = Notes::CreateService.new(project, user, opts).execute
       end
 
       it { expect(@note).to be_valid }
       it { expect(@note.note).to eq(opts[:note]) }
+    end
 
-      it_behaves_like 'note on noteable that supports slash commands' do
-        let(:noteable) { create(:issue, project: project) }
-      end
+    describe 'note with commands' do
+      describe '/close, /label, /assign & /milestone' do
+        let(:note_text) { %(HELLO\n/close\n/assign @#{user.username}\nWORLD) }
 
-      it_behaves_like 'note on noteable that supports slash commands' do
-        let(:noteable) { create(:merge_request, source_project: project) }
-      end
+        it 'saves the note and does not alter the note text' do
+          expect_any_instance_of(Issues::UpdateService).to receive(:execute).and_call_original
 
-      it_behaves_like 'note on noteable that does not support slash commands' do
-        let(:noteable) { create(:commit, project: project) }
+          note = described_class.new(project, user, opts.merge(note: note_text)).execute
+
+          expect(note.note).to eq "HELLO\nWORLD"
+        end
       end
     end
   end
diff --git a/spec/services/notes/slash_commands_service_spec.rb b/spec/services/notes/slash_commands_service_spec.rb
new file mode 100644
index 00000000000..5632ec09834
--- /dev/null
+++ b/spec/services/notes/slash_commands_service_spec.rb
@@ -0,0 +1,129 @@
+require 'spec_helper'
+
+describe Notes::SlashCommandsService, services: true do
+  shared_context 'note on noteable' do
+    let(:project) { create(:empty_project) }
+    let(:master) { create(:user).tap { |u| project.team << [u, :master] } }
+    let(:assignee) { create(:user) }
+  end
+
+  shared_examples 'note on noteable that does not support slash commands' do
+    include_context 'note on noteable'
+
+    before do
+      note.note = note_text
+      described_class.new(project, master).execute(note)
+    end
+
+    describe 'note with only command' do
+      describe '/close, /label, /assign & /milestone' do
+        let(:note_text) { %(/close\n/assign @#{assignee.username}") }
+
+        it 'saves the note and does not alter the note text' do
+          expect(note.note).to eq note_text
+        end
+      end
+    end
+
+    describe 'note with command & text' do
+      describe '/close, /label, /assign & /milestone' do
+        let(:note_text) { %(HELLO\n/close\n/assign @#{assignee.username}\nWORLD) }
+
+        it 'saves the note and does not alter the note text' do
+          expect(note.note).to eq note_text
+        end
+      end
+    end
+  end
+
+  shared_examples 'note on noteable that supports slash commands' do
+    include_context 'note on noteable'
+
+    before do
+      note.note = note_text
+    end
+
+    let!(:milestone) { create(:milestone, project: project) }
+    let!(:labels) { create_pair(:label, project: project) }
+
+    describe 'note with only command' do
+      describe '/close, /label, /assign & /milestone' do
+        let(:note_text) do
+          %(/close\n/label ~#{labels.first.name} ~#{labels.last.name}\n/assign @#{assignee.username}\n/milestone %"#{milestone.name}")
+        end
+
+        it 'closes noteable, sets labels, assigns, and sets milestone to noteable, and leave no note' do
+          described_class.new(project, master).execute(note)
+
+          expect(note.note).to eq ''
+          expect(note.noteable).to be_closed
+          expect(note.noteable.labels).to match_array(labels)
+          expect(note.noteable.assignee).to eq(assignee)
+          expect(note.noteable.milestone).to eq(milestone)
+        end
+      end
+
+      describe '/open' do
+        before do
+          note.noteable.close!
+          expect(note.noteable).to be_closed
+        end
+        let(:note_text) { '/open' }
+
+        it 'opens the noteable, and leave no note' do
+          described_class.new(project, master).execute(note)
+
+          expect(note.note).to eq ''
+          expect(note.noteable).to be_open
+        end
+      end
+    end
+
+    describe 'note with command & text' do
+      describe '/close, /label, /assign & /milestone' do
+        let(:note_text) do
+          %(HELLO\n/close\n/label ~#{labels.first.name} ~#{labels.last.name}\n/assign @#{assignee.username}\n/milestone %"#{milestone.name}"\nWORLD)
+        end
+
+        it 'closes noteable, sets labels, assigns, and sets milestone to noteable' do
+          described_class.new(project, master).execute(note)
+
+          expect(note.note).to eq "HELLO\nWORLD"
+          expect(note.noteable).to be_closed
+          expect(note.noteable.labels).to match_array(labels)
+          expect(note.noteable.assignee).to eq(assignee)
+          expect(note.noteable.milestone).to eq(milestone)
+        end
+      end
+
+      describe '/open' do
+        before do
+          note.noteable.close
+          expect(note.noteable).to be_closed
+        end
+        let(:note_text) { "HELLO\n/open\nWORLD" }
+
+        it 'opens the noteable' do
+          described_class.new(project, master).execute(note)
+
+          expect(note.note).to eq "HELLO\nWORLD"
+          expect(note.noteable).to be_open
+        end
+      end
+    end
+  end
+
+  describe '#execute' do
+    it_behaves_like 'note on noteable that supports slash commands' do
+      let(:note) { build(:note_on_issue, project: project) }
+    end
+
+    it_behaves_like 'note on noteable that supports slash commands' do
+      let(:note) { build(:note_on_merge_request, project: project) }
+    end
+
+    it_behaves_like 'note on noteable that does not support slash commands' do
+      let(:note) { build(:note_on_commit, project: project) }
+    end
+  end
+end
diff --git a/spec/services/slash_commands/interpret_service_spec.rb b/spec/services/slash_commands/interpret_service_spec.rb
index fa0f65495ce..d03c84f59b3 100644
--- a/spec/services/slash_commands/interpret_service_spec.rb
+++ b/spec/services/slash_commands/interpret_service_spec.rb
@@ -18,8 +18,7 @@ describe SlashCommands::InterpretService, services: true do
         :assign, :reassign,
         :unassign, :remove_assignee,
         :milestone,
-        :remove_milestone,
-        :clear_milestone,
+        :clear_milestone, :remove_milestone,
         :labels, :label,
         :unlabel, :remove_labels, :remove_label,
         :clear_labels, :clear_label,
@@ -35,10 +34,12 @@ describe SlashCommands::InterpretService, services: true do
 
   describe '#execute' do
     let(:service) { described_class.new(project, user) }
+    let(:issue) { create(:issue) }
+    let(:merge_request) { create(:merge_request) }
 
     shared_examples 'open command' do
       it 'returns state_event: "open" if content contains /open' do
-        changes = service.execute(content)
+        changes = service.execute(content, issuable)
 
         expect(changes).to eq(state_event: 'reopen')
       end
@@ -46,7 +47,7 @@ describe SlashCommands::InterpretService, services: true do
 
     shared_examples 'close command' do
       it 'returns state_event: "close" if content contains /open' do
-        changes = service.execute(content)
+        changes = service.execute(content, issuable)
 
         expect(changes).to eq(state_event: 'close')
       end
@@ -54,31 +55,47 @@ describe SlashCommands::InterpretService, services: true do
 
     shared_examples 'assign command' do
       it 'fetches assignee and populates assignee_id if content contains /assign' do
-        changes = service.execute(content)
+        changes = service.execute(content, issuable)
 
         expect(changes).to eq(assignee_id: user.id)
       end
     end
 
+    shared_examples 'unassign command' do
+      it 'populates assignee_id: nil if content contains /unassign' do
+        changes = service.execute(content, issuable)
+
+        expect(changes).to eq(assignee_id: nil)
+      end
+    end
+
     shared_examples 'milestone command' do
       it 'fetches milestone and populates milestone_id if content contains /milestone' do
-        changes = service.execute(content)
+        changes = service.execute(content, issuable)
 
         expect(changes).to eq(milestone_id: milestone.id)
       end
     end
 
+    shared_examples 'clear_milestone command' do
+      it 'populates milestone_id: nil if content contains /clear_milestone' do
+        changes = service.execute(content, issuable)
+
+        expect(changes).to eq(milestone_id: nil)
+      end
+    end
+
     shared_examples 'label command' do
       it 'fetches label ids and populates add_label_ids if content contains /label' do
-        changes = service.execute(content)
+        changes = service.execute(content, issuable)
 
         expect(changes).to eq(add_label_ids: [bug.id, inprogress.id])
       end
     end
 
-    shared_examples 'remove_labels command' do
-      it 'fetches label ids and populates remove_label_ids if content contains /label' do
-        changes = service.execute(content)
+    shared_examples 'unlabel command' do
+      it 'fetches label ids and populates remove_label_ids if content contains /unlabel' do
+        changes = service.execute(content, issuable)
 
         expect(changes).to eq(remove_label_ids: [inprogress.id])
       end
@@ -86,15 +103,63 @@ describe SlashCommands::InterpretService, services: true do
 
     shared_examples 'clear_labels command' do
       it 'populates label_ids: [] if content contains /clear_labels' do
-        changes = service.execute(content)
+        changes = service.execute(content, issuable)
 
         expect(changes).to eq(label_ids: [])
       end
     end
 
-    shared_examples 'command returning no changes' do
-      it 'returns an empty hash if content contains /open' do
-        changes = service.execute(content)
+    shared_examples 'todo command' do
+      it 'populates todo_event: "mark" if content contains /todo' do
+        changes = service.execute(content, issuable)
+
+        expect(changes).to eq(todo_event: 'mark')
+      end
+    end
+
+    shared_examples 'done command' do
+      it 'populates todo_event: "done" if content contains /done' do
+        changes = service.execute(content, issuable)
+
+        expect(changes).to eq(todo_event: 'done')
+      end
+    end
+
+    shared_examples 'subscribe command' do
+      it 'populates subscription_event: "subscribe" if content contains /subscribe' do
+        changes = service.execute(content, issuable)
+
+        expect(changes).to eq(subscription_event: 'subscribe')
+      end
+    end
+
+    shared_examples 'unsubscribe command' do
+      it 'populates subscription_event: "unsubscribe" if content contains /unsubscribe' do
+        changes = service.execute(content, issuable)
+
+        expect(changes).to eq(subscription_event: 'unsubscribe')
+      end
+    end
+
+    shared_examples 'due_date command' do
+      it 'populates due_date: Date.new(2016, 8, 28) if content contains /due_date 2016-08-28' do
+        changes = service.execute(content, issuable)
+
+        expect(changes).to eq(due_date: Date.new(2016, 8, 28))
+      end
+    end
+
+    shared_examples 'clear_due_date command' do
+      it 'populates due_date: nil if content contains /clear_due_date' do
+        changes = service.execute(content, issuable)
+
+        expect(changes).to eq(due_date: nil)
+      end
+    end
+
+    shared_examples 'empty command' do
+      it 'populates {} if content contains an unsupported command' do
+        changes = service.execute(content, issuable)
 
         expect(changes).to be_empty
       end
@@ -102,116 +167,204 @@ describe SlashCommands::InterpretService, services: true do
 
     it_behaves_like 'open command' do
       let(:content) { '/open' }
+      let(:issuable) { issue }
+    end
+
+    it_behaves_like 'open command' do
+      let(:content) { '/open' }
+      let(:issuable) { merge_request }
     end
 
     it_behaves_like 'open command' do
       let(:content) { '/reopen' }
+      let(:issuable) { issue }
     end
 
     it_behaves_like 'close command' do
       let(:content) { '/close' }
+      let(:issuable) { issue }
+    end
+
+    it_behaves_like 'close command' do
+      let(:content) { '/close' }
+      let(:issuable) { merge_request }
     end
 
     it_behaves_like 'assign command' do
       let(:content) { "/assign @#{user.username}" }
+      let(:issuable) { issue }
+    end
+
+    it_behaves_like 'assign command' do
+      let(:content) { "/assign @#{user.username}" }
+      let(:issuable) { merge_request }
     end
 
     it 'does not populate assignee_id if content contains /assign with an unknown user' do
-      changes = service.execute('/assign joe')
+      changes = service.execute('/assign joe', issue)
 
       expect(changes).to be_empty
     end
 
     it 'does not populate assignee_id if content contains /assign without user' do
-      changes = service.execute('/assign')
+      changes = service.execute('/assign', issue)
 
       expect(changes).to be_empty
     end
 
-    it 'populates assignee_id: nil if content contains /unassign' do
-      changes = service.execute('/unassign')
+    it_behaves_like 'unassign command' do
+      let(:content) { '/unassign' }
+      let(:issuable) { issue }
+    end
 
-      expect(changes).to eq(assignee_id: nil)
+    it_behaves_like 'unassign command' do
+      let(:content) { '/unassign' }
+      let(:issuable) { merge_request }
+    end
+
+    it_behaves_like 'unassign command' do
+      let(:content) { '/remove_assignee' }
+      let(:issuable) { issue }
     end
 
     it_behaves_like 'milestone command' do
       let(:content) { "/milestone %#{milestone.title}" }
+      let(:issuable) { issue }
     end
 
-    it 'populates milestone_id: nil if content contains /clear_milestone' do
-      changes = service.execute('/clear_milestone')
+    it_behaves_like 'milestone command' do
+      let(:content) { "/milestone %#{milestone.title}" }
+      let(:issuable) { merge_request }
+    end
 
-      expect(changes).to eq(milestone_id: nil)
+    it_behaves_like 'clear_milestone command' do
+      let(:content) { '/clear_milestone' }
+      let(:issuable) { issue }
+    end
+
+    it_behaves_like 'clear_milestone command' do
+      let(:content) { '/clear_milestone' }
+      let(:issuable) { merge_request }
+    end
+
+    it_behaves_like 'clear_milestone command' do
+      let(:content) { '/remove_milestone' }
+      let(:issuable) { issue }
     end
 
     it_behaves_like 'label command' do
       let(:content) { %(/label ~"#{inprogress.title}" ~#{bug.title} ~unknown) }
+      let(:issuable) { issue }
+    end
+
+    it_behaves_like 'label command' do
+      let(:content) { %(/label ~"#{inprogress.title}" ~#{bug.title} ~unknown) }
+      let(:issuable) { merge_request }
     end
 
     it_behaves_like 'label command' do
       let(:content) { %(/labels ~"#{inprogress.title}" ~#{bug.title} ~unknown) }
+      let(:issuable) { issue }
     end
 
-    it_behaves_like 'remove_labels command' do
+    it_behaves_like 'unlabel command' do
       let(:content) { %(/unlabel ~"#{inprogress.title}") }
+      let(:issuable) { issue }
     end
 
-    it_behaves_like 'remove_labels command' do
+    it_behaves_like 'unlabel command' do
+      let(:content) { %(/unlabel ~"#{inprogress.title}") }
+      let(:issuable) { merge_request }
+    end
+
+    it_behaves_like 'unlabel command' do
       let(:content) { %(/remove_labels ~"#{inprogress.title}") }
+      let(:issuable) { issue }
     end
 
-    it_behaves_like 'remove_labels command' do
+    it_behaves_like 'unlabel command' do
       let(:content) { %(/remove_label ~"#{inprogress.title}") }
+      let(:issuable) { issue }
     end
 
     it_behaves_like 'clear_labels command' do
       let(:content) { '/clear_labels' }
+      let(:issuable) { issue }
+    end
+
+    it_behaves_like 'clear_labels command' do
+      let(:content) { '/clear_labels' }
+      let(:issuable) { merge_request }
     end
 
     it_behaves_like 'clear_labels command' do
       let(:content) { '/clear_label' }
+      let(:issuable) { issue }
     end
 
-    it 'populates todo: :mark if content contains /todo' do
-      changes = service.execute('/todo')
-
-      expect(changes).to eq(todo_event: 'mark')
+    it_behaves_like 'todo command' do
+      let(:content) { '/todo' }
+      let(:issuable) { issue }
     end
 
-    it 'populates todo: :done if content contains /done' do
-      changes = service.execute('/done')
-
-      expect(changes).to eq(todo_event: 'done')
+    it_behaves_like 'todo command' do
+      let(:content) { '/todo' }
+      let(:issuable) { merge_request }
     end
 
-    it 'populates subscription: :subscribe if content contains /subscribe' do
-      changes = service.execute('/subscribe')
-
-      expect(changes).to eq(subscription_event: 'subscribe')
+    it_behaves_like 'done command' do
+      let(:content) { '/done' }
+      let(:issuable) { issue }
     end
 
-    it 'populates subscription: :unsubscribe if content contains /unsubscribe' do
-      changes = service.execute('/unsubscribe')
-
-      expect(changes).to eq(subscription_event: 'unsubscribe')
+    it_behaves_like 'done command' do
+      let(:content) { '/done' }
+      let(:issuable) { merge_request }
     end
 
-    it 'populates due_date: Time.now.tomorrow if content contains /due_date 2016-08-28' do
-      changes = service.execute('/due_date 2016-08-28')
-
-      expect(changes).to eq(due_date: Date.new(2016, 8, 28))
+    it_behaves_like 'subscribe command' do
+      let(:content) { '/subscribe' }
+      let(:issuable) { issue }
     end
 
-    it 'populates due_date: Time.now.tomorrow if content contains /due_date foo' do
-      changes = service.execute('/due_date foo')
-
-      expect(changes).to be_empty
+    it_behaves_like 'subscribe command' do
+      let(:content) { '/subscribe' }
+      let(:issuable) { merge_request }
     end
 
-    it 'populates due_date: nil if content contains /clear_due_date' do
-      changes = service.execute('/clear_due_date')
+    it_behaves_like 'unsubscribe command' do
+      let(:content) { '/unsubscribe' }
+      let(:issuable) { issue }
+    end
 
-      expect(changes).to eq(due_date: nil)
+    it_behaves_like 'unsubscribe command' do
+      let(:content) { '/unsubscribe' }
+      let(:issuable) { merge_request }
+    end
+
+    it_behaves_like 'due_date command' do
+      let(:content) { '/due_date 2016-08-28' }
+      let(:issuable) { issue }
+    end
+
+    it_behaves_like 'empty command' do
+      let(:content) { '/due_date foo bar' }
+      let(:issuable) { issue }
+    end
+
+    it_behaves_like 'empty command' do
+      let(:content) { '/due_date 2016-08-28' }
+      let(:issuable) { merge_request }
+    end
+
+    it_behaves_like 'clear_due_date command' do
+      let(:content) { '/clear_due_date' }
+      let(:issuable) { issue }
+    end
+
+    it_behaves_like 'empty command' do
+      let(:content) { '/clear_due_date' }
+      let(:issuable) { merge_request }
     end
   end
 end
diff --git a/spec/support/issuable_slash_commands_shared_examples.rb b/spec/support/issuable_slash_commands_shared_examples.rb
index 3b8783cb053..824ccb0ddfb 100644
--- a/spec/support/issuable_slash_commands_shared_examples.rb
+++ b/spec/support/issuable_slash_commands_shared_examples.rb
@@ -118,7 +118,7 @@ shared_examples 'issuable record that supports slash commands in its description
           end
 
           expect(page).not_to have_content '/close'
-          expect(page).to have_content 'Your commands are being executed.'
+          expect(page).not_to have_content 'Your commands are being executed.'
 
           expect(issuable).to be_open
         end
@@ -159,7 +159,7 @@ shared_examples 'issuable record that supports slash commands in its description
           end
 
           expect(page).not_to have_content '/reopen'
-          expect(page).to have_content 'Your commands are being executed.'
+          expect(page).not_to have_content 'Your commands are being executed.'
 
           expect(issuable).to be_closed
         end
diff --git a/spec/support/note_create_service_slash_commands_shared_examples.rb b/spec/support/note_create_service_slash_commands_shared_examples.rb
deleted file mode 100644
index 3f7ad8b2f91..00000000000
--- a/spec/support/note_create_service_slash_commands_shared_examples.rb
+++ /dev/null
@@ -1,116 +0,0 @@
-# Specifications for behavior common to all note objects with executable attributes.
-# It expects a `noteable` object for which the note is posted.
-
-shared_context 'note on noteable' do
-  let!(:project) { create(:project) }
-  let(:user) { create(:user).tap { |u| project.team << [u, :master] } }
-  let(:assignee) { create(:user) }
-  let(:base_params) { { noteable: noteable } }
-  let(:params) { base_params.merge(example_params) }
-  let(:note) { described_class.new(project, user, params).execute }
-end
-
-shared_examples 'note on noteable that does not support slash commands' do
-  include_context 'note on noteable'
-
-  let(:params) { { commit_id: noteable.id, noteable_type: 'Commit' }.merge(example_params) }
-
-  describe 'note with only command' do
-    describe '/close, /label, /assign & /milestone' do
-      let(:note_text) { %(/close\n/assign @#{assignee.username}") }
-      let(:example_params) { { note: note_text } }
-
-      it 'saves the note and does not alter the note text' do
-        expect(note).to be_persisted
-        expect(note.note).to eq note_text
-      end
-    end
-  end
-
-  describe 'note with command & text' do
-    describe '/close, /label, /assign & /milestone' do
-      let(:note_text) { %(HELLO\n/close\n/assign @#{assignee.username}\nWORLD) }
-      let(:example_params) { { note: note_text } }
-
-      it 'saves the note and does not alter the note text' do
-        expect(note).to be_persisted
-        expect(note.note).to eq note_text
-      end
-    end
-  end
-end
-
-shared_examples 'note on noteable that supports slash commands' do
-  include_context 'note on noteable'
-
-  let!(:milestone) { create(:milestone, project: project) }
-  let!(:labels) { create_pair(:label, project: project) }
-
-  describe 'note with only command' do
-    describe '/close, /label, /assign & /milestone' do
-      let(:example_params) do
-        {
-          note: %(/close\n/label ~#{labels.first.name} ~#{labels.last.name}\n/assign @#{assignee.username}\n/milestone %"#{milestone.name}")
-        }
-      end
-
-      it 'closes noteable, sets labels, assigns, and sets milestone to noteable, and leave no note' do
-        expect(note).not_to be_persisted
-        expect(note.note).to eq ''
-        expect(noteable).to be_closed
-        expect(noteable.labels).to match_array(labels)
-        expect(noteable.assignee).to eq(assignee)
-        expect(noteable.milestone).to eq(milestone)
-      end
-    end
-
-    describe '/open' do
-      let(:noteable) { create(:issue, project: project, state: :closed) }
-      let(:example_params) do
-        {
-          note: '/open'
-        }
-      end
-
-      it 'opens the noteable, and leave no note' do
-        expect(note).not_to be_persisted
-        expect(note.note).to eq ''
-        expect(noteable).to be_open
-      end
-    end
-  end
-
-  describe 'note with command & text' do
-    describe '/close, /label, /assign & /milestone' do
-      let(:example_params) do
-        {
-          note: %(HELLO\n/close\n/label ~#{labels.first.name} ~#{labels.last.name}\n/assign @#{assignee.username}\n/milestone %"#{milestone.name}"\nWORLD)
-        }
-      end
-
-      it 'closes noteable, sets labels, assigns, and sets milestone to noteable' do
-        expect(note).to be_persisted
-        expect(note.note).to eq "HELLO\nWORLD"
-        expect(noteable).to be_closed
-        expect(noteable.labels).to match_array(labels)
-        expect(noteable.assignee).to eq(assignee)
-        expect(noteable.milestone).to eq(milestone)
-      end
-    end
-
-    describe '/open' do
-      let(:noteable) { create(:issue, project: project, state: :closed) }
-      let(:example_params) do
-        {
-          note: "HELLO\n/open\nWORLD"
-        }
-      end
-
-      it 'opens the noteable' do
-        expect(note).to be_persisted
-        expect(note.note).to eq "HELLO\nWORLD"
-        expect(noteable).to be_open
-      end
-    end
-  end
-end

From 39f7f63fe951ff861ad151125188e6cdd598b6ff Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Coutable?= <remy@rymai.me>
Date: Tue, 9 Aug 2016 20:54:18 +0200
Subject: [PATCH 04/25] Add the /title slash command
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Rémy Coutable <remy@rymai.me>
---
 app/services/issuable_base_service.rb         |  2 +-
 .../slash_commands/interpret_service.rb       |  6 +++
 doc/workflow/slash_commands.md                |  3 +-
 .../email/handler/create_note_handler_spec.rb | 15 +++++++-
 .../slash_commands/interpret_service_spec.rb  | 38 +++++++++++++++----
 ...issuable_slash_commands_shared_examples.rb | 37 ++++++++++++++++++
 6 files changed, 89 insertions(+), 12 deletions(-)

diff --git a/app/services/issuable_base_service.rb b/app/services/issuable_base_service.rb
index 3512e2b735e..1ef7a2433dc 100644
--- a/app/services/issuable_base_service.rb
+++ b/app/services/issuable_base_service.rb
@@ -86,7 +86,7 @@ class IssuableBaseService < BaseService
     remove_label_ids = attributes.delete(:remove_label_ids)
 
     new_label_ids = base_label_ids
-    new_label_ids = label_ids if label_ids && (merge_all || (add_label_ids.empty? && remove_label_ids.empty?))
+    new_label_ids = label_ids if label_ids && (merge_all || (add_label_ids.blank? && remove_label_ids.blank?))
     new_label_ids |= add_label_ids if add_label_ids
     new_label_ids -= remove_label_ids if remove_label_ids
 
diff --git a/app/services/slash_commands/interpret_service.rb b/app/services/slash_commands/interpret_service.rb
index bff61683976..74825f30868 100644
--- a/app/services/slash_commands/interpret_service.rb
+++ b/app/services/slash_commands/interpret_service.rb
@@ -34,6 +34,12 @@ module SlashCommands
       @updates[:state_event] = 'reopen'
     end
 
+    desc 'Change title'
+    params '<New title>'
+    command :title do |title_param|
+      @updates[:title] = title_param
+    end
+
     desc 'Reassign'
     params '@user'
     command :assign, :reassign do |assignee_param|
diff --git a/doc/workflow/slash_commands.md b/doc/workflow/slash_commands.md
index 3bfc66309ba..bf5b8ebe1c8 100644
--- a/doc/workflow/slash_commands.md
+++ b/doc/workflow/slash_commands.md
@@ -13,6 +13,7 @@ do.
 |:---------------------------|:--------------------|:-------------|
 | `/close`                   | None                | Close the issue or merge request |
 | `/open`                    | `/reopen`           | Reopen the issue or merge request |
+| `/title <New title>`       | None                | Change title |
 | `/assign @username`        | `/reassign`         | Reassign |
 | `/unassign`                | `/remove_assignee`  | Remove assignee |
 | `/milestone %milestone`    | None                | Change milestone |
@@ -24,5 +25,5 @@ do.
 | `/done`                    | None                | Mark todo as done |
 | `/subscribe`               | None                | Subscribe |
 | `/unsubscribe`             | None                | Unsubscribe |
-| `/due_date`                | None                | Set a due date |
+| `/due_date <YYYY-MM-DD> | <N days>` | None       | Set a due date |
 | `/clear_due_date`          | None                | Remove due date |
diff --git a/spec/lib/gitlab/email/handler/create_note_handler_spec.rb b/spec/lib/gitlab/email/handler/create_note_handler_spec.rb
index e2339c5e103..afb072105cf 100644
--- a/spec/lib/gitlab/email/handler/create_note_handler_spec.rb
+++ b/spec/lib/gitlab/email/handler/create_note_handler_spec.rb
@@ -64,10 +64,21 @@ describe Gitlab::Email::Handler::CreateNoteHandler, lib: true do
     context 'because the note was commands only' do
       let!(:email_raw) { fixture_file("emails/commands_only_reply.eml") }
 
-      it 'raises a CommandsOnlyNoteError' do
-        expect { receiver.execute }.not_to raise_error
+      context 'and current user cannot update noteable' do
+        it 'raises a CommandsOnlyNoteError' do
+          expect { receiver.execute }.to raise_error(Gitlab::Email::InvalidNoteError)
+        end
       end
 
+      context 'and current user can update noteable' do
+        before do
+          project.team << [user, :developer]
+        end
+
+        it 'raises a CommandsOnlyNoteError' do
+          expect { receiver.execute }.not_to raise_error
+        end
+      end
     end
   end
 
diff --git a/spec/services/slash_commands/interpret_service_spec.rb b/spec/services/slash_commands/interpret_service_spec.rb
index d03c84f59b3..66ebe091893 100644
--- a/spec/services/slash_commands/interpret_service_spec.rb
+++ b/spec/services/slash_commands/interpret_service_spec.rb
@@ -15,6 +15,7 @@ describe SlashCommands::InterpretService, services: true do
       is_expected.to match_array([
         :open, :reopen,
         :close,
+        :title,
         :assign, :reassign,
         :unassign, :remove_assignee,
         :milestone,
@@ -53,6 +54,14 @@ describe SlashCommands::InterpretService, services: true do
       end
     end
 
+    shared_examples 'title command' do
+      it 'populates title: "A brand new title" if content contains /title A brand new title' do
+        changes = service.execute(content, issuable)
+
+        expect(changes).to eq(title: 'A brand new title')
+      end
+    end
+
     shared_examples 'assign command' do
       it 'fetches assignee and populates assignee_id if content contains /assign' do
         changes = service.execute(content, issuable)
@@ -190,6 +199,21 @@ describe SlashCommands::InterpretService, services: true do
       let(:issuable) { merge_request }
     end
 
+    it_behaves_like 'title command' do
+      let(:content) { '/title A brand new title' }
+      let(:issuable) { issue }
+    end
+
+    it_behaves_like 'title command' do
+      let(:content) { '/title A brand new title' }
+      let(:issuable) { merge_request }
+    end
+
+    it_behaves_like 'empty command' do
+      let(:content) { '/title' }
+      let(:issuable) { issue }
+    end
+
     it_behaves_like 'assign command' do
       let(:content) { "/assign @#{user.username}" }
       let(:issuable) { issue }
@@ -200,16 +224,14 @@ describe SlashCommands::InterpretService, services: true do
       let(:issuable) { merge_request }
     end
 
-    it 'does not populate assignee_id if content contains /assign with an unknown user' do
-      changes = service.execute('/assign joe', issue)
-
-      expect(changes).to be_empty
+    it_behaves_like 'empty command' do
+      let(:content) { '/assign @abcd1234' }
+      let(:issuable) { issue }
     end
 
-    it 'does not populate assignee_id if content contains /assign without user' do
-      changes = service.execute('/assign', issue)
-
-      expect(changes).to be_empty
+    it_behaves_like 'empty command' do
+      let(:content) { '/assign' }
+      let(:issuable) { issue }
     end
 
     it_behaves_like 'unassign command' do
diff --git a/spec/support/issuable_slash_commands_shared_examples.rb b/spec/support/issuable_slash_commands_shared_examples.rb
index 824ccb0ddfb..4f2e7c3bee8 100644
--- a/spec/support/issuable_slash_commands_shared_examples.rb
+++ b/spec/support/issuable_slash_commands_shared_examples.rb
@@ -166,6 +166,43 @@ shared_examples 'issuable record that supports slash commands in its description
       end
     end
 
+    context "with a note changing the #{issuable_type}'s title" do
+      context "when current user can change title of #{issuable_type}" do
+        it "reopens the #{issuable_type}" do
+          page.within('.js-main-target-form') do
+            fill_in 'note[note]', with: "/title Awesome new title"
+            click_button 'Comment'
+          end
+
+          expect(page).not_to have_content '/title'
+          expect(page).to have_content 'Your commands are being executed.'
+
+          expect(issuable.reload.title).to eq 'Awesome new title'
+        end
+      end
+
+      context "when current user cannot change title of #{issuable_type}" do
+        before do
+          logout
+          login_with(guest)
+          visit public_send("namespace_project_#{issuable_type}_path", project.namespace, project, issuable)
+        end
+
+        it "does not reopen the #{issuable_type}" do
+          current_title = issuable.title
+          page.within('.js-main-target-form') do
+            fill_in 'note[note]', with: "/title Awesome new title"
+            click_button 'Comment'
+          end
+
+          expect(page).not_to have_content '/title'
+          expect(page).not_to have_content 'Your commands are being executed.'
+
+          expect(issuable.reload.title).not_to eq 'Awesome new title'
+        end
+      end
+    end
+
     context "with a note marking the #{issuable_type} as todo" do
       it "creates a new todo for the #{issuable_type}" do
         page.within('.js-main-target-form') do

From e021604454f1093b7d762b28eae36e30083f0053 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Coutable?= <remy@rymai.me>
Date: Tue, 9 Aug 2016 22:47:29 +0200
Subject: [PATCH 05/25] Don't extract slash commands inside blockcode,
 blockquote or HTML tags
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Improve slash command descriptions, support /due tomorrow

Signed-off-by: Rémy Coutable <remy@rymai.me>
---
 app/services/issuable_base_service.rb         |  2 +-
 .../slash_commands/interpret_service.rb       | 14 +++--
 doc/workflow/slash_commands.md                |  6 +--
 lib/gitlab/slash_commands/extractor.rb        | 51 +++++++++++++++++--
 .../gitlab/slash_commands/extractor_spec.rb   | 27 ++++++++++
 .../slash_commands/interpret_service_spec.rb  | 14 +++--
 6 files changed, 98 insertions(+), 16 deletions(-)

diff --git a/app/services/issuable_base_service.rb b/app/services/issuable_base_service.rb
index 1ef7a2433dc..c14bda811c2 100644
--- a/app/services/issuable_base_service.rb
+++ b/app/services/issuable_base_service.rb
@@ -173,7 +173,7 @@ class IssuableBaseService < BaseService
 
   def change_todo(issuable)
     case params.delete(:todo_event)
-    when 'mark'
+    when 'add'
       todo_service.mark_todo(issuable, current_user)
     when 'done'
       todo = TodosFinder.new(current_user).execute.find_by(target: issuable)
diff --git a/app/services/slash_commands/interpret_service.rb b/app/services/slash_commands/interpret_service.rb
index 74825f30868..3030af05999 100644
--- a/app/services/slash_commands/interpret_service.rb
+++ b/app/services/slash_commands/interpret_service.rb
@@ -40,7 +40,7 @@ module SlashCommands
       @updates[:title] = title_param
     end
 
-    desc 'Reassign'
+    desc 'Assign'
     params '@user'
     command :assign, :reassign do |assignee_param|
       user = extract_references(assignee_param, :user).first
@@ -54,7 +54,7 @@ module SlashCommands
       @updates[:assignee_id] = nil
     end
 
-    desc 'Change milestone'
+    desc 'Set milestone'
     params '%"milestone"'
     command :milestone do |milestone_param|
       milestone = extract_references(milestone_param, :milestone).first
@@ -93,7 +93,7 @@ module SlashCommands
 
     desc 'Add a todo'
     command :todo do
-      @updates[:todo_event] = 'mark'
+      @updates[:todo_event] = 'add'
     end
 
     desc 'Mark todo as done'
@@ -113,11 +113,15 @@ module SlashCommands
 
     desc 'Set a due date'
     params '<YYYY-MM-DD> | <N days>'
-    command :due_date do |due_date_param|
+    command :due_date, :due do |due_date_param|
       return unless noteable.respond_to?(:due_date)
 
       due_date = begin
-        Time.now + ChronicDuration.parse(due_date_param)
+        if due_date_param.downcase == 'tomorrow'
+          Date.tomorrow
+        else
+          Time.now + ChronicDuration.parse(due_date_param)
+        end
       rescue ChronicDuration::DurationParseError
         Date.parse(due_date_param) rescue nil
       end
diff --git a/doc/workflow/slash_commands.md b/doc/workflow/slash_commands.md
index bf5b8ebe1c8..46f291561d7 100644
--- a/doc/workflow/slash_commands.md
+++ b/doc/workflow/slash_commands.md
@@ -14,9 +14,9 @@ do.
 | `/close`                   | None                | Close the issue or merge request |
 | `/open`                    | `/reopen`           | Reopen the issue or merge request |
 | `/title <New title>`       | None                | Change title |
-| `/assign @username`        | `/reassign`         | Reassign |
+| `/assign @username`        | `/reassign`         | Assign |
 | `/unassign`                | `/remove_assignee`  | Remove assignee |
-| `/milestone %milestone`    | None                | Change milestone |
+| `/milestone %milestone`    | None                | Set milestone |
 | `/clear_milestone`         | `/remove_milestone` | Remove milestone |
 | `/label ~foo ~"bar baz"`   | `/labels`           | Add label(s) |
 | `/unlabel ~foo ~"bar baz"` | `/remove_label`, `remove_labels` | Remove label(s) |
@@ -25,5 +25,5 @@ do.
 | `/done`                    | None                | Mark todo as done |
 | `/subscribe`               | None                | Subscribe |
 | `/unsubscribe`             | None                | Unsubscribe |
-| `/due_date <YYYY-MM-DD> | <N days>` | None       | Set a due date |
+| `/due_date <YYYY-MM-DD> | <N days>` | `/due`     | Set a due date |
 | `/clear_due_date`          | None                | Remove due date |
diff --git a/lib/gitlab/slash_commands/extractor.rb b/lib/gitlab/slash_commands/extractor.rb
index 1a854b81aca..ce0a2eba535 100644
--- a/lib/gitlab/slash_commands/extractor.rb
+++ b/lib/gitlab/slash_commands/extractor.rb
@@ -34,9 +34,14 @@ module Gitlab
 
         commands = []
 
+        content.delete!("\r")
         content.gsub!(commands_regex) do
-          commands << [$1, $2].flatten.reject(&:blank?)
-          ''
+          if $~[:cmd]
+            commands << [$~[:cmd], $~[:args]].reject(&:blank?)
+            ''
+          else
+            $~[0]
+          end
         end
 
         commands
@@ -52,7 +57,47 @@ module Gitlab
       #
       #   /^\/(?<cmd>close|reopen|...)(?:( |$))(?<args>[^\/\n]*)(?:\n|$)/
       def commands_regex
-        /^\/(?<cmd>#{command_names.join('|')})(?:( |$))(?<args>[^\/\n]*)(?:\n|$)/
+        @commands_regex ||= %r{
+            (?<code>
+              # Code blocks:
+              # ```
+              # Anything, including `/cmd args` which are ignored by this filter
+              # ```
+
+              ^```
+              .+?
+              \n```$
+            )
+          |
+            (?<html>
+              # HTML block:
+              # <tag>
+              # Anything, including `/cmd args` which are ignored by this filter
+              # </tag>
+
+              ^<[^>]+?>\n
+              .+?
+              \n<\/[^>]+?>$
+            )
+          |
+            (?<html>
+              # Quote block:
+              # >>>
+              # Anything, including `/cmd args` which are ignored by this filter
+              # >>>
+
+              ^>>>
+              .+?
+              \n>>>$
+            )
+          |
+            (?:
+              # Command not in a blockquote, blockcode, or HTML tag:
+              # /close
+
+              ^\/(?<cmd>#{command_names.join('|')})(?:(\ |$))(?<args>[^\/\n]*)(?:\n|$)
+            )
+        }mx
       end
     end
   end
diff --git a/spec/lib/gitlab/slash_commands/extractor_spec.rb b/spec/lib/gitlab/slash_commands/extractor_spec.rb
index fd1b30052ed..11836b10204 100644
--- a/spec/lib/gitlab/slash_commands/extractor_spec.rb
+++ b/spec/lib/gitlab/slash_commands/extractor_spec.rb
@@ -173,5 +173,32 @@ describe Gitlab::SlashCommands::Extractor do
       expect(commands).to be_empty
       expect(msg).to eq 'Fixes #123'
     end
+
+    it 'does not extract commands inside a blockcode' do
+      msg = msg = "Hello\r\n```\r\nThis is some text\r\n/close\r\n/assign @user\r\n```\r\n\r\nWorld"
+      expected = msg.delete("\r")
+      commands = extractor.extract_commands!(msg)
+
+      expect(commands).to be_empty
+      expect(msg).to eq expected
+    end
+
+    it 'does not extract commands inside a blockquote' do
+      msg = "Hello\r\n>>>\r\nThis is some text\r\n/close\r\n/assign @user\r\n>>>\r\n\r\nWorld"
+      expected = msg.delete("\r")
+      commands = extractor.extract_commands!(msg)
+
+      expect(commands).to be_empty
+      expect(msg).to eq expected
+    end
+
+    it 'does not extract commands inside a HTML tag' do
+      msg = msg = "Hello\r\n<div>\r\nThis is some text\r\n/close\r\n/assign @user\r\n</div>\r\n\r\nWorld"
+      expected = msg.delete("\r")
+      commands = extractor.extract_commands!(msg)
+
+      expect(commands).to be_empty
+      expect(msg).to eq expected
+    end
   end
 end
diff --git a/spec/services/slash_commands/interpret_service_spec.rb b/spec/services/slash_commands/interpret_service_spec.rb
index 66ebe091893..620687e3212 100644
--- a/spec/services/slash_commands/interpret_service_spec.rb
+++ b/spec/services/slash_commands/interpret_service_spec.rb
@@ -27,7 +27,7 @@ describe SlashCommands::InterpretService, services: true do
         :done,
         :subscribe,
         :unsubscribe,
-        :due_date,
+        :due_date, :due,
         :clear_due_date
       ])
     end
@@ -119,10 +119,10 @@ describe SlashCommands::InterpretService, services: true do
     end
 
     shared_examples 'todo command' do
-      it 'populates todo_event: "mark" if content contains /todo' do
+      it 'populates todo_event: "add" if content contains /todo' do
         changes = service.execute(content, issuable)
 
-        expect(changes).to eq(todo_event: 'mark')
+        expect(changes).to eq(todo_event: 'add')
       end
     end
 
@@ -154,7 +154,7 @@ describe SlashCommands::InterpretService, services: true do
       it 'populates due_date: Date.new(2016, 8, 28) if content contains /due_date 2016-08-28' do
         changes = service.execute(content, issuable)
 
-        expect(changes).to eq(due_date: Date.new(2016, 8, 28))
+        expect(changes).to eq(due_date: defined?(expected_date) ? expected_date : Date.new(2016, 8, 28))
       end
     end
 
@@ -369,6 +369,12 @@ describe SlashCommands::InterpretService, services: true do
       let(:issuable) { issue }
     end
 
+    it_behaves_like 'due_date command' do
+      let(:content) { '/due tomorrow' }
+      let(:issuable) { issue }
+      let(:expected_date) { Date.tomorrow }
+    end
+
     it_behaves_like 'empty command' do
       let(:content) { '/due_date foo bar' }
       let(:issuable) { issue }

From 23db6449542498636c145e83c71a4a466eb62746 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Coutable?= <remy@rymai.me>
Date: Wed, 10 Aug 2016 14:12:09 +0200
Subject: [PATCH 06/25] Add support for no-op slash commands that appear in
 autocomplete
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The first one is /cc

Signed-off-by: Rémy Coutable <remy@rymai.me>
---
 app/services/slash_commands/interpret_service.rb | 10 +++++++++-
 lib/gitlab/slash_commands/dsl.rb                 | 14 +++++++++++---
 spec/lib/gitlab/slash_commands/dsl_spec.rb       | 16 +++++++++++-----
 spec/lib/gitlab/slash_commands/extractor_spec.rb |  4 ++--
 .../issuable_slash_commands_shared_examples.rb   |  5 ++---
 5 files changed, 35 insertions(+), 14 deletions(-)

diff --git a/app/services/slash_commands/interpret_service.rb b/app/services/slash_commands/interpret_service.rb
index 3030af05999..55b14f118d0 100644
--- a/app/services/slash_commands/interpret_service.rb
+++ b/app/services/slash_commands/interpret_service.rb
@@ -117,7 +117,7 @@ module SlashCommands
       return unless noteable.respond_to?(:due_date)
 
       due_date = begin
-        if due_date_param.downcase == 'tomorrow'
+        if due_date_param.casecmp('tomorrow').zero?
           Date.tomorrow
         else
           Time.now + ChronicDuration.parse(due_date_param)
@@ -136,6 +136,14 @@ module SlashCommands
       @updates[:due_date] = nil
     end
 
+    # This is a dummy command, so that it appears in the autocomplete commands
+    desc 'CC'
+    params '@user'
+    noop true
+    command :cc do
+      return
+    end
+
     def find_label_ids(labels_param)
       extract_references(labels_param, :label).map(&:id)
     end
diff --git a/lib/gitlab/slash_commands/dsl.rb b/lib/gitlab/slash_commands/dsl.rb
index 3ded4109f2e..edfe8405876 100644
--- a/lib/gitlab/slash_commands/dsl.rb
+++ b/lib/gitlab/slash_commands/dsl.rb
@@ -14,8 +14,10 @@ module Gitlab
 
         def command_names
           command_definitions.flat_map do |command_definition|
-            [command_definition[:name], command_definition[:aliases]].flatten
-          end
+            unless command_definition[:noop]
+              [command_definition[:name], command_definition[:aliases]].flatten
+            end
+          end.compact
         end
 
         # Allows to give a description to the next slash command
@@ -28,6 +30,11 @@ module Gitlab
           @params = params
         end
 
+        # Allows to define if a command is a no-op, but should appear in autocomplete
+        def noop(noop)
+          @noop = noop
+        end
+
         # Registers a new command which is recognizeable
         # from body of email or comment.
         # Example:
@@ -63,7 +70,8 @@ module Gitlab
             name: command_name,
             aliases: aliases,
             description: @description || '',
-            params: @params || []
+            params: @params || [],
+            noop: @noop || false
           }
           @command_definitions << command_definition
 
diff --git a/spec/lib/gitlab/slash_commands/dsl_spec.rb b/spec/lib/gitlab/slash_commands/dsl_spec.rb
index f8abb35674d..39e1996c891 100644
--- a/spec/lib/gitlab/slash_commands/dsl_spec.rb
+++ b/spec/lib/gitlab/slash_commands/dsl_spec.rb
@@ -29,6 +29,11 @@ describe Gitlab::SlashCommands::Dsl do
       command :wildcard do |*args|
         args
       end
+
+      noop true
+      command :cc do |*args|
+        args
+      end
     end
   end
   let(:dummy) { DummyClass.new }
@@ -36,11 +41,12 @@ describe Gitlab::SlashCommands::Dsl do
   describe '.command_definitions' do
     it 'returns an array with commands definitions' do
       expected = [
-        { name: :no_args, aliases: [:none], description: 'A command with no args', params: [] },
-        { name: :returning, aliases: [], description: 'A command returning a value', params: [] },
-        { name: :one_arg, aliases: [:once, :first], description: '', params: ['The first argument'] },
-        { name: :two_args, aliases: [], description: 'A command with two args', params: ['The first argument', 'The second argument'] },
-        { name: :wildcard, aliases: [], description: '', params: [] }
+        { name: :no_args, aliases: [:none], description: 'A command with no args', params: [], noop: false },
+        { name: :returning, aliases: [], description: 'A command returning a value', params: [], noop: false },
+        { name: :one_arg, aliases: [:once, :first], description: '', params: ['The first argument'], noop: false },
+        { name: :two_args, aliases: [], description: 'A command with two args', params: ['The first argument', 'The second argument'], noop: false },
+        { name: :wildcard, aliases: [], description: '', params: [], noop: false },
+        { name: :cc, aliases: [], description: '', params: [], noop: true }
       ]
 
       expect(DummyClass.command_definitions).to eq expected
diff --git a/spec/lib/gitlab/slash_commands/extractor_spec.rb b/spec/lib/gitlab/slash_commands/extractor_spec.rb
index 11836b10204..ac7296bdba1 100644
--- a/spec/lib/gitlab/slash_commands/extractor_spec.rb
+++ b/spec/lib/gitlab/slash_commands/extractor_spec.rb
@@ -175,7 +175,7 @@ describe Gitlab::SlashCommands::Extractor do
     end
 
     it 'does not extract commands inside a blockcode' do
-      msg = msg = "Hello\r\n```\r\nThis is some text\r\n/close\r\n/assign @user\r\n```\r\n\r\nWorld"
+      msg = "Hello\r\n```\r\nThis is some text\r\n/close\r\n/assign @user\r\n```\r\n\r\nWorld"
       expected = msg.delete("\r")
       commands = extractor.extract_commands!(msg)
 
@@ -193,7 +193,7 @@ describe Gitlab::SlashCommands::Extractor do
     end
 
     it 'does not extract commands inside a HTML tag' do
-      msg = msg = "Hello\r\n<div>\r\nThis is some text\r\n/close\r\n/assign @user\r\n</div>\r\n\r\nWorld"
+      msg = "Hello\r\n<div>\r\nThis is some text\r\n/close\r\n/assign @user\r\n</div>\r\n\r\nWorld"
       expected = msg.delete("\r")
       commands = extractor.extract_commands!(msg)
 
diff --git a/spec/support/issuable_slash_commands_shared_examples.rb b/spec/support/issuable_slash_commands_shared_examples.rb
index 4f2e7c3bee8..e1255bd248d 100644
--- a/spec/support/issuable_slash_commands_shared_examples.rb
+++ b/spec/support/issuable_slash_commands_shared_examples.rb
@@ -28,7 +28,7 @@ shared_examples 'issuable record that supports slash commands in its description
 
         issuable = project.public_send(issuable_type.to_s.pluralize).first
 
-        expect(issuable.description).to eq "bug description\r\n"
+        expect(issuable.description).to eq "bug description\n"
         expect(issuable.labels).to eq [label_bug]
         expect(issuable.milestone).to eq milestone
         expect(page).to have_content 'bug 345'
@@ -57,7 +57,7 @@ shared_examples 'issuable record that supports slash commands in its description
         issuable.reload
         note = issuable.notes.user.first
 
-        expect(note.note).to eq "Awesome!\r\n"
+        expect(note.note).to eq "Awesome!\n"
         expect(issuable.assignee).to eq assignee
         expect(issuable.labels).to eq [label_bug]
         expect(issuable.milestone).to eq milestone
@@ -189,7 +189,6 @@ shared_examples 'issuable record that supports slash commands in its description
         end
 
         it "does not reopen the #{issuable_type}" do
-          current_title = issuable.title
           page.within('.js-main-target-form') do
             fill_in 'note[note]', with: "/title Awesome new title"
             click_button 'Comment'

From 65349c22129fcdf2ae0c7103094bbf50ae73db61 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Coutable?= <remy@rymai.me>
Date: Wed, 10 Aug 2016 17:51:01 +0200
Subject: [PATCH 07/25] Make slash commands contextual
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

- Return only slash commands that make sense for the current noteable
- Allow slash commands decription to be dynamic

Other improvements:

- Add permission checks in slash commands definition
- Use IssuesFinder and MergeRequestsFinder
- Use next if instead of a unless block, and use splat operator instead of flatten

Signed-off-by: Rémy Coutable <remy@rymai.me>
---
 Gemfile                                       |   3 +-
 Gemfile.lock                                  |   2 +
 app/controllers/projects_controller.rb        |   2 +-
 app/services/projects/autocomplete_service.rb |  23 ++-
 .../slash_commands/interpret_service.rb       | 137 +++++++++++---
 doc/workflow/slash_commands.md                |   2 +-
 lib/gitlab/slash_commands/dsl.rb              |  40 ++++-
 spec/fixtures/emails/commands_only_reply.eml  |   2 +-
 spec/lib/gitlab/slash_commands/dsl_spec.rb    |  82 +++++++--
 .../slash_commands/interpret_service_spec.rb  | 168 ++++++++++++++++--
 10 files changed, 395 insertions(+), 66 deletions(-)

diff --git a/Gemfile b/Gemfile
index 8b44b54e22c..7c7889fb946 100644
--- a/Gemfile
+++ b/Gemfile
@@ -209,7 +209,8 @@ gem 'mousetrap-rails', '~> 1.4.6'
 # Detect and convert string character encoding
 gem 'charlock_holmes', '~> 0.7.3'
 
-# Parse duration
+# Parse time & duration
+gem 'chronic', '~> 0.10.2'
 gem 'chronic_duration', '~> 0.10.6'
 
 gem 'sass-rails', '~> 5.0.0'
diff --git a/Gemfile.lock b/Gemfile.lock
index 3ba6048143c..ecce224adeb 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -128,6 +128,7 @@ GEM
       mime-types (>= 1.16)
     cause (0.1)
     charlock_holmes (0.7.3)
+    chronic (0.10.2)
     chronic_duration (0.10.6)
       numerizer (~> 0.1.1)
     chunky_png (1.3.5)
@@ -822,6 +823,7 @@ DEPENDENCIES
   capybara-screenshot (~> 1.0.0)
   carrierwave (~> 0.10.0)
   charlock_holmes (~> 0.7.3)
+  chronic (~> 0.10.2)
   chronic_duration (~> 0.10.6)
   coffee-rails (~> 4.1.0)
   connection_pool (~> 2.0)
diff --git a/app/controllers/projects_controller.rb b/app/controllers/projects_controller.rb
index 64d31e4a3a0..af20984cbe7 100644
--- a/app/controllers/projects_controller.rb
+++ b/app/controllers/projects_controller.rb
@@ -146,7 +146,7 @@ class ProjectsController < Projects::ApplicationController
       mergerequests: autocomplete.merge_requests,
       labels: autocomplete.labels,
       members: participants,
-      commands: autocomplete.commands
+      commands: autocomplete.commands(note_type, note_id)
     }
 
     respond_to do |format|
diff --git a/app/services/projects/autocomplete_service.rb b/app/services/projects/autocomplete_service.rb
index e943d2ffbcb..779f64f584e 100644
--- a/app/services/projects/autocomplete_service.rb
+++ b/app/services/projects/autocomplete_service.rb
@@ -16,8 +16,27 @@ module Projects
       @project.labels.select([:title, :color])
     end
 
-    def commands
-      SlashCommands::InterpretService.command_definitions
+    def commands(noteable_type, noteable_id)
+      SlashCommands::InterpretService.command_definitions(
+        project: @project,
+        noteable: command_target(noteable_type, noteable_id),
+        current_user: current_user
+      )
+    end
+
+    private
+
+    def command_target(noteable_type, noteable_id)
+      case noteable_type
+      when 'Issue'
+        IssuesFinder.new(current_user, project_id: @project.id, state: 'all').
+          execute.find_or_initialize_by(iid: noteable_id)
+      when 'MergeRequest'
+        MergeRequestsFinder.new(current_user, project_id: @project.id, state: 'all').
+          execute.find_or_initialize_by(iid: noteable_id)
+      else
+        nil
+      end
     end
   end
 end
diff --git a/app/services/slash_commands/interpret_service.rb b/app/services/slash_commands/interpret_service.rb
index 55b14f118d0..e94ee83df85 100644
--- a/app/services/slash_commands/interpret_service.rb
+++ b/app/services/slash_commands/interpret_service.rb
@@ -10,7 +10,7 @@ module SlashCommands
       @noteable = noteable
       @updates = {}
 
-      commands = extractor.extract_commands!(content)
+      commands = extractor(noteable: noteable).extract_commands!(content)
       commands.each do |command|
         __send__(*command)
       end
@@ -20,28 +20,57 @@ module SlashCommands
 
     private
 
-    def extractor
-      @extractor ||= Gitlab::SlashCommands::Extractor.new(self.class.command_names)
+    def extractor(opts = {})
+      opts.merge!(current_user: current_user, project: project)
+
+      Gitlab::SlashCommands::Extractor.new(self.class.command_names(opts))
     end
 
-    desc 'Close this issue or merge request'
+    desc ->(opts) { "Close this #{opts[:noteable].to_ability_name.humanize(capitalize: false)}" }
+    condition ->(opts) do
+      opts[:noteable] &&
+      opts[:noteable].open? &&
+      opts[:current_user] &&
+      opts[:project] &&
+      opts[:current_user].can?(:"update_#{opts[:noteable].to_ability_name}", opts[:project])
+    end
     command :close do
       @updates[:state_event] = 'close'
     end
 
-    desc 'Reopen this issue or merge request'
+    desc ->(opts) { "Reopen this #{opts[:noteable].to_ability_name.humanize(capitalize: false)}" }
+    condition ->(opts) do
+      opts[:noteable] &&
+      opts[:noteable].closed? &&
+      opts[:current_user] &&
+      opts[:project] &&
+      opts[:current_user].can?(:"update_#{opts[:noteable].to_ability_name}", opts[:project])
+    end
     command :open, :reopen do
       @updates[:state_event] = 'reopen'
     end
 
     desc 'Change title'
     params '<New title>'
+    condition ->(opts) do
+      opts[:noteable] &&
+      opts[:noteable].persisted? &&
+      opts[:current_user] &&
+      opts[:project] &&
+      opts[:current_user].can?(:"update_#{opts[:noteable].to_ability_name}", opts[:project])
+    end
     command :title do |title_param|
       @updates[:title] = title_param
     end
 
     desc 'Assign'
     params '@user'
+    condition ->(opts) do
+      opts[:noteable] &&
+      opts[:current_user] &&
+      opts[:project] &&
+      opts[:current_user].can?(:"admin_#{opts[:noteable].to_ability_name}", opts[:project])
+    end
     command :assign, :reassign do |assignee_param|
       user = extract_references(assignee_param, :user).first
       return unless user
@@ -50,12 +79,26 @@ module SlashCommands
     end
 
     desc 'Remove assignee'
+    condition ->(opts) do
+      opts[:noteable] &&
+      opts[:noteable].assignee_id? &&
+      opts[:current_user] &&
+      opts[:project] &&
+      opts[:current_user].can?(:"admin_#{opts[:noteable].to_ability_name}", opts[:project])
+    end
     command :unassign, :remove_assignee do
       @updates[:assignee_id] = nil
     end
 
     desc 'Set milestone'
     params '%"milestone"'
+    condition ->(opts) do
+      opts[:noteable] &&
+      opts[:current_user] &&
+      opts[:project] &&
+      opts[:current_user].can?(:"admin_#{opts[:noteable].to_ability_name}", opts[:project]) &&
+      opts[:project].milestones.active.any?
+    end
     command :milestone do |milestone_param|
       milestone = extract_references(milestone_param, :milestone).first
       return unless milestone
@@ -64,12 +107,26 @@ module SlashCommands
     end
 
     desc 'Remove milestone'
+    condition ->(opts) do
+      opts[:noteable] &&
+      opts[:noteable].milestone_id? &&
+      opts[:current_user] &&
+      opts[:project] &&
+      opts[:current_user].can?(:"admin_#{opts[:noteable].to_ability_name}", opts[:project])
+    end
     command :clear_milestone, :remove_milestone do
       @updates[:milestone_id] = nil
     end
 
     desc 'Add label(s)'
     params '~label1 ~"label 2"'
+    condition ->(opts) do
+      opts[:noteable] &&
+      opts[:current_user] &&
+      opts[:project] &&
+      opts[:current_user].can?(:"admin_#{opts[:noteable].to_ability_name}", opts[:project]) &&
+      opts[:project].labels.any?
+    end
     command :label, :labels do |labels_param|
       label_ids = find_label_ids(labels_param)
       return if label_ids.empty?
@@ -79,6 +136,13 @@ module SlashCommands
 
     desc 'Remove label(s)'
     params '~label1 ~"label 2"'
+    condition ->(opts) do
+      opts[:noteable] &&
+      opts[:noteable].labels.any? &&
+      opts[:current_user] &&
+      opts[:project] &&
+      opts[:current_user].can?(:"admin_#{opts[:noteable].to_ability_name}", opts[:project])
+    end
     command :unlabel, :remove_label, :remove_labels do |labels_param|
       label_ids = find_label_ids(labels_param)
       return if label_ids.empty?
@@ -87,52 +151,85 @@ module SlashCommands
     end
 
     desc 'Remove all labels'
+    condition ->(opts) do
+      opts[:noteable] &&
+      opts[:noteable].labels.any? &&
+      opts[:current_user] &&
+      opts[:project] &&
+      opts[:current_user].can?(:"admin_#{opts[:noteable].to_ability_name}", opts[:project])
+    end
     command :clear_labels, :clear_label do
       @updates[:label_ids] = []
     end
 
     desc 'Add a todo'
+    condition ->(opts) do
+      opts[:noteable] &&
+      opts[:noteable].persisted? &&
+      opts[:current_user] &&
+      !TodosFinder.new(opts[:current_user]).execute.exists?(target: opts[:noteable])
+    end
     command :todo do
       @updates[:todo_event] = 'add'
     end
 
     desc 'Mark todo as done'
+    condition ->(opts) do
+      opts[:noteable] &&
+      opts[:current_user] &&
+      TodosFinder.new(opts[:current_user]).execute.exists?(target: opts[:noteable])
+    end
     command :done do
       @updates[:todo_event] = 'done'
     end
 
     desc 'Subscribe'
+    condition ->(opts) do
+      opts[:noteable] &&
+      opts[:current_user] &&
+      opts[:noteable].persisted? &&
+      !opts[:noteable].subscribed?(opts[:current_user])
+    end
     command :subscribe do
       @updates[:subscription_event] = 'subscribe'
     end
 
     desc 'Unsubscribe'
+    condition ->(opts) do
+      opts[:noteable] &&
+      opts[:current_user] &&
+      opts[:noteable].persisted? &&
+      opts[:noteable].subscribed?(opts[:current_user])
+    end
     command :unsubscribe do
       @updates[:subscription_event] = 'unsubscribe'
     end
 
-    desc 'Set a due date'
-    params '<YYYY-MM-DD> | <N days>'
+    desc 'Set due date'
+    params 'a date in natural language'
+    condition ->(opts) do
+      opts[:noteable] &&
+      opts[:noteable].respond_to?(:due_date) &&
+      opts[:current_user] &&
+      opts[:project] &&
+      opts[:current_user].can?(:"update_#{opts[:noteable].to_ability_name}", opts[:project])
+    end
     command :due_date, :due do |due_date_param|
-      return unless noteable.respond_to?(:due_date)
-
-      due_date = begin
-        if due_date_param.casecmp('tomorrow').zero?
-          Date.tomorrow
-        else
-          Time.now + ChronicDuration.parse(due_date_param)
-        end
-      rescue ChronicDuration::DurationParseError
-        Date.parse(due_date_param) rescue nil
-      end
+      due_date = Chronic.parse(due_date_param).try(:to_date)
 
       @updates[:due_date] = due_date if due_date
     end
 
     desc 'Remove due date'
+    condition ->(opts) do
+      opts[:noteable] &&
+      opts[:noteable].respond_to?(:due_date) &&
+      opts[:noteable].due_date? &&
+      opts[:current_user] &&
+      opts[:project] &&
+      opts[:current_user].can?(:"update_#{opts[:noteable].to_ability_name}", opts[:project])
+    end
     command :clear_due_date do
-      return unless noteable.respond_to?(:due_date)
-
       @updates[:due_date] = nil
     end
 
diff --git a/doc/workflow/slash_commands.md b/doc/workflow/slash_commands.md
index 46f291561d7..c4edbeddd40 100644
--- a/doc/workflow/slash_commands.md
+++ b/doc/workflow/slash_commands.md
@@ -25,5 +25,5 @@ do.
 | `/done`                    | None                | Mark todo as done |
 | `/subscribe`               | None                | Subscribe |
 | `/unsubscribe`             | None                | Unsubscribe |
-| `/due_date <YYYY-MM-DD> | <N days>` | `/due`     | Set a due date |
+| `/due_date a date in natural language` | `/due`  | Set due date |
 | `/clear_due_date`          | None                | Remove due date |
diff --git a/lib/gitlab/slash_commands/dsl.rb b/lib/gitlab/slash_commands/dsl.rb
index edfe8405876..20e1d071d06 100644
--- a/lib/gitlab/slash_commands/dsl.rb
+++ b/lib/gitlab/slash_commands/dsl.rb
@@ -8,15 +8,25 @@ module Gitlab
       end
 
       module ClassMethods
-        def command_definitions
-          @command_definitions
+        def command_definitions(opts = {})
+          @command_definitions.map do |cmd_def|
+            next if cmd_def[:cond_lambda] && !cmd_def[:cond_lambda].call(opts)
+
+            cmd_def = cmd_def.dup
+
+            if cmd_def[:description].present? && cmd_def[:description].respond_to?(:call)
+              cmd_def[:description] = cmd_def[:description].call(opts) rescue ''
+            end
+
+            cmd_def
+          end.compact
         end
 
-        def command_names
-          command_definitions.flat_map do |command_definition|
-            unless command_definition[:noop]
-              [command_definition[:name], command_definition[:aliases]].flatten
-            end
+        def command_names(opts = {})
+          command_definitions(opts).flat_map do |command_definition|
+            next if command_definition[:noop]
+
+            [command_definition[:name], *command_definition[:aliases]]
           end.compact
         end
 
@@ -35,6 +45,11 @@ module Gitlab
           @noop = noop
         end
 
+        # Allows to define if a lambda to conditionally return an action
+        def condition(cond_lambda)
+          @cond_lambda = cond_lambda
+        end
+
         # Registers a new command which is recognizeable
         # from body of email or comment.
         # Example:
@@ -53,6 +68,10 @@ module Gitlab
           define_method(proxy_method_name, &block)
 
           define_method(command_name) do |*args|
+            unless @cond_lambda.nil? || @cond_lambda.call(project: project, current_user: current_user, noteable: noteable)
+              return
+            end
+
             proxy_method = method(proxy_method_name)
 
             if proxy_method.arity == -1 || proxy_method.arity == args.size
@@ -70,13 +89,16 @@ module Gitlab
             name: command_name,
             aliases: aliases,
             description: @description || '',
-            params: @params || [],
-            noop: @noop || false
+            params: @params || []
           }
+          command_definition[:noop] = @noop unless @noop.nil?
+          command_definition[:cond_lambda] = @cond_lambda unless @cond_lambda.nil?
           @command_definitions << command_definition
 
           @description = nil
           @params = nil
+          @noop = nil
+          @cond_lambda = nil
         end
       end
     end
diff --git a/spec/fixtures/emails/commands_only_reply.eml b/spec/fixtures/emails/commands_only_reply.eml
index b64d851a79c..ccd92e406c4 100644
--- a/spec/fixtures/emails/commands_only_reply.eml
+++ b/spec/fixtures/emails/commands_only_reply.eml
@@ -20,7 +20,7 @@ X-Received: by 10.0.0.1 with SMTP id n7mr11234144ipb.85.1371157428600; Thu,
 X-Scanned-By: MIMEDefang 2.69 on IPv6:2001:470:1d:165::1
 
 /close
-/unsubscribe
+/todo
 
 
 On Sun, Jun 9, 2013 at 1:39 PM, eviltrout via Discourse Meta
diff --git a/spec/lib/gitlab/slash_commands/dsl_spec.rb b/spec/lib/gitlab/slash_commands/dsl_spec.rb
index 39e1996c891..893a7692f11 100644
--- a/spec/lib/gitlab/slash_commands/dsl_spec.rb
+++ b/spec/lib/gitlab/slash_commands/dsl_spec.rb
@@ -1,6 +1,7 @@
 require 'spec_helper'
 
 describe Gitlab::SlashCommands::Dsl do
+  COND_LAMBDA = ->(opts) { opts[:project] == 'foo' }
   before :all do
     DummyClass = Class.new do
       include Gitlab::SlashCommands::Dsl
@@ -20,18 +21,23 @@ describe Gitlab::SlashCommands::Dsl do
         arg1
       end
 
-      desc 'A command with two args'
+      desc ->(opts) { "A dynamic description for #{opts.fetch(:noteable)}" }
       params 'The first argument', 'The second argument'
       command :two_args do |arg1, arg2|
         [arg1, arg2]
       end
 
-      command :wildcard do |*args|
+      noop true
+      command :cc do |*args|
         args
       end
 
-      noop true
-      command :cc do |*args|
+      condition COND_LAMBDA
+      command :cond_action do |*args|
+        args
+      end
+
+      command :wildcard do |*args|
         args
       end
     end
@@ -39,27 +45,73 @@ describe Gitlab::SlashCommands::Dsl do
   let(:dummy) { DummyClass.new }
 
   describe '.command_definitions' do
-    it 'returns an array with commands definitions' do
-      expected = [
-        { name: :no_args, aliases: [:none], description: 'A command with no args', params: [], noop: false },
-        { name: :returning, aliases: [], description: 'A command returning a value', params: [], noop: false },
-        { name: :one_arg, aliases: [:once, :first], description: '', params: ['The first argument'], noop: false },
-        { name: :two_args, aliases: [], description: 'A command with two args', params: ['The first argument', 'The second argument'], noop: false },
-        { name: :wildcard, aliases: [], description: '', params: [], noop: false },
-        { name: :cc, aliases: [], description: '', params: [], noop: true }
+    let(:base_expected) do
+      [
+        { name: :no_args, aliases: [:none], description: 'A command with no args', params: [] },
+        { name: :returning, aliases: [], description: 'A command returning a value', params: [] },
+        { name: :one_arg, aliases: [:once, :first], description: '', params: ['The first argument'] },
+        { name: :two_args, aliases: [], description: '', params: ['The first argument', 'The second argument'] },
+        { name: :cc, aliases: [], description: '', params: [], noop: true },
+        { name: :wildcard, aliases: [], description: '', params: [] }
       ]
+    end
 
-      expect(DummyClass.command_definitions).to eq expected
+    it 'returns an array with commands definitions' do
+      expect(DummyClass.command_definitions).to match_array base_expected
+    end
+
+    context 'with options passed' do
+      context 'when condition is met' do
+        let(:expected) { base_expected << { name: :cond_action, aliases: [], description: '', params: [], cond_lambda: COND_LAMBDA } }
+
+        it 'returns an array with commands definitions' do
+          expect(DummyClass.command_definitions(project: 'foo')).to match_array expected
+        end
+      end
+
+      context 'when condition is not met' do
+        it 'returns an array with commands definitions without actions that did not met conditions' do
+          expect(DummyClass.command_definitions(project: 'bar')).to match_array base_expected
+        end
+      end
+
+      context 'when description can be generated dynamically' do
+        it 'returns an array with commands definitions with dynamic descriptions' do
+          base_expected[3][:description] = 'A dynamic description for merge request'
+
+          expect(DummyClass.command_definitions(noteable: 'merge request')).to match_array base_expected
+        end
+      end
     end
   end
 
   describe '.command_names' do
-    it 'returns an array with commands definitions' do
-      expect(DummyClass.command_names).to eq [
+    let(:base_expected) do
+      [
         :no_args, :none, :returning, :one_arg,
         :once, :first, :two_args, :wildcard
       ]
     end
+
+    it 'returns an array with commands definitions' do
+      expect(DummyClass.command_names).to eq base_expected
+    end
+
+    context 'with options passed' do
+      context 'when condition is met' do
+        let(:expected) { base_expected << :cond_action }
+
+        it 'returns an array with commands definitions' do
+          expect(DummyClass.command_names(project: 'foo')).to match_array expected
+        end
+      end
+
+      context 'when condition is not met' do
+        it 'returns an array with commands definitions without action that did not met conditions' do
+          expect(DummyClass.command_names(project: 'bar')).to match_array base_expected
+        end
+      end
+    end
   end
 
   describe 'command with no args' do
diff --git a/spec/services/slash_commands/interpret_service_spec.rb b/spec/services/slash_commands/interpret_service_spec.rb
index 620687e3212..0cf77e53435 100644
--- a/spec/services/slash_commands/interpret_service_spec.rb
+++ b/spec/services/slash_commands/interpret_service_spec.rb
@@ -8,38 +8,152 @@ describe SlashCommands::InterpretService, services: true do
   let(:inprogress) { create(:label, project: project, title: 'In Progress') }
   let(:bug) { create(:label, project: project, title: 'Bug') }
 
-  describe '#command_names' do
-    subject { described_class.command_names }
+  before do
+    project.team << [user, :developer]
+  end
 
-    it 'returns the known commands' do
+  describe '#command_names' do
+    subject do
+      described_class.command_names(
+        project: project,
+        noteable: issue,
+        current_user: user
+      )
+    end
+
+    it 'returns the basic known commands' do
       is_expected.to match_array([
-        :open, :reopen,
         :close,
         :title,
         :assign, :reassign,
-        :unassign, :remove_assignee,
-        :milestone,
-        :clear_milestone, :remove_milestone,
-        :labels, :label,
-        :unlabel, :remove_labels, :remove_label,
-        :clear_labels, :clear_label,
         :todo,
-        :done,
         :subscribe,
-        :unsubscribe,
-        :due_date, :due,
-        :clear_due_date
+        :due_date, :due
       ])
     end
+
+    context 'when noteable is open' do
+      it 'includes the :close command' do
+        is_expected.to include(*[:close])
+      end
+    end
+
+    context 'when noteable is closed' do
+      before do
+        issue.close!
+      end
+
+      it 'includes the :open, :reopen commands' do
+        is_expected.to include(*[:open, :reopen])
+      end
+    end
+
+    context 'when noteable has an assignee' do
+      before do
+        issue.update(assignee_id: user.id)
+      end
+
+      it 'includes the :unassign, :remove_assignee commands' do
+        is_expected.to include(*[:unassign, :remove_assignee])
+      end
+    end
+
+    context 'when noteable has a milestone' do
+      before do
+        issue.update(milestone: milestone)
+      end
+
+      it 'includes the :clear_milestone, :remove_milestone commands' do
+        is_expected.to include(*[:milestone, :clear_milestone, :remove_milestone])
+      end
+    end
+
+    context 'when project has a milestone' do
+      before do
+        milestone
+      end
+
+      it 'includes the :milestone command' do
+        is_expected.to include(*[:milestone])
+      end
+    end
+
+    context 'when noteable has a label' do
+      before do
+        issue.update(label_ids: [bug.id])
+      end
+
+      it 'includes the :unlabel, :remove_labels, :remove_label, :clear_labels, :clear_label commands' do
+        is_expected.to include(*[:unlabel, :remove_labels, :remove_label, :clear_labels, :clear_label])
+      end
+    end
+
+    context 'when project has a label' do
+      before do
+        inprogress
+      end
+
+      it 'includes the :labels, :label commands' do
+        is_expected.to include(*[:labels, :label])
+      end
+    end
+
+    context 'when user has no todo' do
+      it 'includes the :todo command' do
+        is_expected.to include(*[:todo])
+      end
+    end
+
+    context 'when user has a todo' do
+      before do
+        TodoService.new.mark_todo(issue, user)
+      end
+
+      it 'includes the :done command' do
+        is_expected.to include(*[:done])
+      end
+    end
+
+    context 'when user is not subscribed' do
+      it 'includes the :subscribe command' do
+        is_expected.to include(*[:subscribe])
+      end
+    end
+
+    context 'when user is subscribed' do
+      before do
+        issue.subscribe(user)
+      end
+
+      it 'includes the :unsubscribe command' do
+        is_expected.to include(*[:unsubscribe])
+      end
+    end
+
+    context 'when noteable has a no due date' do
+      it 'includes the :due_date, :due commands' do
+        is_expected.to include(*[:due_date, :due])
+      end
+    end
+
+    context 'when noteable has a due date' do
+      before do
+        issue.update(due_date: Date.today)
+      end
+
+      it 'includes the :clear_due_date command' do
+        is_expected.to include(*[:due_date, :due, :clear_due_date])
+      end
+    end
   end
 
   describe '#execute' do
     let(:service) { described_class.new(project, user) }
-    let(:issue) { create(:issue) }
-    let(:merge_request) { create(:merge_request) }
+    let(:merge_request) { create(:merge_request, source_project: project) }
 
     shared_examples 'open command' do
       it 'returns state_event: "open" if content contains /open' do
+        issuable.close!
         changes = service.execute(content, issuable)
 
         expect(changes).to eq(state_event: 'reopen')
@@ -72,6 +186,7 @@ describe SlashCommands::InterpretService, services: true do
 
     shared_examples 'unassign command' do
       it 'populates assignee_id: nil if content contains /unassign' do
+        issuable.update(assignee_id: user.id)
         changes = service.execute(content, issuable)
 
         expect(changes).to eq(assignee_id: nil)
@@ -80,6 +195,7 @@ describe SlashCommands::InterpretService, services: true do
 
     shared_examples 'milestone command' do
       it 'fetches milestone and populates milestone_id if content contains /milestone' do
+        milestone # populate the milestone
         changes = service.execute(content, issuable)
 
         expect(changes).to eq(milestone_id: milestone.id)
@@ -88,6 +204,7 @@ describe SlashCommands::InterpretService, services: true do
 
     shared_examples 'clear_milestone command' do
       it 'populates milestone_id: nil if content contains /clear_milestone' do
+        issuable.update(milestone_id: milestone.id)
         changes = service.execute(content, issuable)
 
         expect(changes).to eq(milestone_id: nil)
@@ -96,6 +213,8 @@ describe SlashCommands::InterpretService, services: true do
 
     shared_examples 'label command' do
       it 'fetches label ids and populates add_label_ids if content contains /label' do
+        bug # populate the label
+        inprogress # populate the label
         changes = service.execute(content, issuable)
 
         expect(changes).to eq(add_label_ids: [bug.id, inprogress.id])
@@ -104,6 +223,7 @@ describe SlashCommands::InterpretService, services: true do
 
     shared_examples 'unlabel command' do
       it 'fetches label ids and populates remove_label_ids if content contains /unlabel' do
+        issuable.update(label_ids: [inprogress.id]) # populate the label
         changes = service.execute(content, issuable)
 
         expect(changes).to eq(remove_label_ids: [inprogress.id])
@@ -112,6 +232,7 @@ describe SlashCommands::InterpretService, services: true do
 
     shared_examples 'clear_labels command' do
       it 'populates label_ids: [] if content contains /clear_labels' do
+        issuable.update(label_ids: [inprogress.id]) # populate the label
         changes = service.execute(content, issuable)
 
         expect(changes).to eq(label_ids: [])
@@ -128,6 +249,7 @@ describe SlashCommands::InterpretService, services: true do
 
     shared_examples 'done command' do
       it 'populates todo_event: "done" if content contains /done' do
+        TodoService.new.mark_todo(issuable, user)
         changes = service.execute(content, issuable)
 
         expect(changes).to eq(todo_event: 'done')
@@ -144,6 +266,7 @@ describe SlashCommands::InterpretService, services: true do
 
     shared_examples 'unsubscribe command' do
       it 'populates subscription_event: "unsubscribe" if content contains /unsubscribe' do
+        issuable.subscribe(user)
         changes = service.execute(content, issuable)
 
         expect(changes).to eq(subscription_event: 'unsubscribe')
@@ -160,6 +283,7 @@ describe SlashCommands::InterpretService, services: true do
 
     shared_examples 'clear_due_date command' do
       it 'populates due_date: nil if content contains /clear_due_date' do
+        issuable.update(due_date: Date.today)
         changes = service.execute(content, issuable)
 
         expect(changes).to eq(due_date: nil)
@@ -375,6 +499,18 @@ describe SlashCommands::InterpretService, services: true do
       let(:expected_date) { Date.tomorrow }
     end
 
+    it_behaves_like 'due_date command' do
+      let(:content) { '/due 5 days from now' }
+      let(:issuable) { issue }
+      let(:expected_date) { 5.days.from_now.to_date }
+    end
+
+    it_behaves_like 'due_date command' do
+      let(:content) { '/due in 2 days' }
+      let(:issuable) { issue }
+      let(:expected_date) { 2.days.from_now.to_date }
+    end
+
     it_behaves_like 'empty command' do
       let(:content) { '/due_date foo bar' }
       let(:issuable) { issue }

From 42e30a5012bb3384ee6f275ff058d4c0841776cd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Coutable?= <remy@rymai.me>
Date: Thu, 11 Aug 2016 18:51:37 +0200
Subject: [PATCH 08/25] Accept blocks for `.desc` and `.condition` slash
 commands DSL
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Also, pass options as instance variables, making the DSL more
user-friendly / natural.

Signed-off-by: Rémy Coutable <remy@rymai.me>
---
 .../slash_commands/interpret_service.rb       | 153 +++++++-----------
 lib/gitlab/slash_commands/dsl.rb              | 113 ++++++++-----
 spec/lib/gitlab/slash_commands/dsl_spec.rb    |  61 ++++---
 3 files changed, 172 insertions(+), 155 deletions(-)

diff --git a/app/services/slash_commands/interpret_service.rb b/app/services/slash_commands/interpret_service.rb
index e94ee83df85..ae22ed6b845 100644
--- a/app/services/slash_commands/interpret_service.rb
+++ b/app/services/slash_commands/interpret_service.rb
@@ -26,25 +26,23 @@ module SlashCommands
       Gitlab::SlashCommands::Extractor.new(self.class.command_names(opts))
     end
 
-    desc ->(opts) { "Close this #{opts[:noteable].to_ability_name.humanize(capitalize: false)}" }
-    condition ->(opts) do
-      opts[:noteable] &&
-      opts[:noteable].open? &&
-      opts[:current_user] &&
-      opts[:project] &&
-      opts[:current_user].can?(:"update_#{opts[:noteable].to_ability_name}", opts[:project])
+    desc do
+      "Close this #{noteable.to_ability_name.humanize(capitalize: false)}"
+    end
+    condition do
+      noteable.open? &&
+      current_user.can?(:"update_#{noteable.to_ability_name}", project)
     end
     command :close do
       @updates[:state_event] = 'close'
     end
 
-    desc ->(opts) { "Reopen this #{opts[:noteable].to_ability_name.humanize(capitalize: false)}" }
-    condition ->(opts) do
-      opts[:noteable] &&
-      opts[:noteable].closed? &&
-      opts[:current_user] &&
-      opts[:project] &&
-      opts[:current_user].can?(:"update_#{opts[:noteable].to_ability_name}", opts[:project])
+    desc do
+      "Reopen this #{noteable.to_ability_name.humanize(capitalize: false)}"
+    end
+    condition do
+      noteable.closed? &&
+      current_user.can?(:"update_#{noteable.to_ability_name}", project)
     end
     command :open, :reopen do
       @updates[:state_event] = 'reopen'
@@ -52,12 +50,9 @@ module SlashCommands
 
     desc 'Change title'
     params '<New title>'
-    condition ->(opts) do
-      opts[:noteable] &&
-      opts[:noteable].persisted? &&
-      opts[:current_user] &&
-      opts[:project] &&
-      opts[:current_user].can?(:"update_#{opts[:noteable].to_ability_name}", opts[:project])
+    condition do
+      noteable.persisted? &&
+      current_user.can?(:"update_#{noteable.to_ability_name}", project)
     end
     command :title do |title_param|
       @updates[:title] = title_param
@@ -65,11 +60,8 @@ module SlashCommands
 
     desc 'Assign'
     params '@user'
-    condition ->(opts) do
-      opts[:noteable] &&
-      opts[:current_user] &&
-      opts[:project] &&
-      opts[:current_user].can?(:"admin_#{opts[:noteable].to_ability_name}", opts[:project])
+    condition do
+      current_user.can?(:"admin_#{noteable.to_ability_name}", project)
     end
     command :assign, :reassign do |assignee_param|
       user = extract_references(assignee_param, :user).first
@@ -79,12 +71,9 @@ module SlashCommands
     end
 
     desc 'Remove assignee'
-    condition ->(opts) do
-      opts[:noteable] &&
-      opts[:noteable].assignee_id? &&
-      opts[:current_user] &&
-      opts[:project] &&
-      opts[:current_user].can?(:"admin_#{opts[:noteable].to_ability_name}", opts[:project])
+    condition do
+      noteable.assignee_id? &&
+      current_user.can?(:"admin_#{noteable.to_ability_name}", project)
     end
     command :unassign, :remove_assignee do
       @updates[:assignee_id] = nil
@@ -92,12 +81,9 @@ module SlashCommands
 
     desc 'Set milestone'
     params '%"milestone"'
-    condition ->(opts) do
-      opts[:noteable] &&
-      opts[:current_user] &&
-      opts[:project] &&
-      opts[:current_user].can?(:"admin_#{opts[:noteable].to_ability_name}", opts[:project]) &&
-      opts[:project].milestones.active.any?
+    condition do
+      current_user.can?(:"admin_#{noteable.to_ability_name}", project) &&
+      project.milestones.active.any?
     end
     command :milestone do |milestone_param|
       milestone = extract_references(milestone_param, :milestone).first
@@ -107,12 +93,9 @@ module SlashCommands
     end
 
     desc 'Remove milestone'
-    condition ->(opts) do
-      opts[:noteable] &&
-      opts[:noteable].milestone_id? &&
-      opts[:current_user] &&
-      opts[:project] &&
-      opts[:current_user].can?(:"admin_#{opts[:noteable].to_ability_name}", opts[:project])
+    condition do
+      noteable.milestone_id? &&
+      current_user.can?(:"admin_#{noteable.to_ability_name}", project)
     end
     command :clear_milestone, :remove_milestone do
       @updates[:milestone_id] = nil
@@ -120,12 +103,9 @@ module SlashCommands
 
     desc 'Add label(s)'
     params '~label1 ~"label 2"'
-    condition ->(opts) do
-      opts[:noteable] &&
-      opts[:current_user] &&
-      opts[:project] &&
-      opts[:current_user].can?(:"admin_#{opts[:noteable].to_ability_name}", opts[:project]) &&
-      opts[:project].labels.any?
+    condition do
+      current_user.can?(:"admin_#{noteable.to_ability_name}", project) &&
+      project.labels.any?
     end
     command :label, :labels do |labels_param|
       label_ids = find_label_ids(labels_param)
@@ -136,12 +116,9 @@ module SlashCommands
 
     desc 'Remove label(s)'
     params '~label1 ~"label 2"'
-    condition ->(opts) do
-      opts[:noteable] &&
-      opts[:noteable].labels.any? &&
-      opts[:current_user] &&
-      opts[:project] &&
-      opts[:current_user].can?(:"admin_#{opts[:noteable].to_ability_name}", opts[:project])
+    condition do
+      noteable.labels.any? &&
+      current_user.can?(:"admin_#{noteable.to_ability_name}", project)
     end
     command :unlabel, :remove_label, :remove_labels do |labels_param|
       label_ids = find_label_ids(labels_param)
@@ -151,55 +128,46 @@ module SlashCommands
     end
 
     desc 'Remove all labels'
-    condition ->(opts) do
-      opts[:noteable] &&
-      opts[:noteable].labels.any? &&
-      opts[:current_user] &&
-      opts[:project] &&
-      opts[:current_user].can?(:"admin_#{opts[:noteable].to_ability_name}", opts[:project])
+    condition do
+      noteable.labels.any? &&
+      current_user.can?(:"admin_#{noteable.to_ability_name}", project)
     end
     command :clear_labels, :clear_label do
       @updates[:label_ids] = []
     end
 
     desc 'Add a todo'
-    condition ->(opts) do
-      opts[:noteable] &&
-      opts[:noteable].persisted? &&
-      opts[:current_user] &&
-      !TodosFinder.new(opts[:current_user]).execute.exists?(target: opts[:noteable])
+    condition do
+      noteable.persisted? &&
+      current_user &&
+      !TodosFinder.new(current_user).execute.exists?(target: noteable)
     end
     command :todo do
       @updates[:todo_event] = 'add'
     end
 
     desc 'Mark todo as done'
-    condition ->(opts) do
-      opts[:noteable] &&
-      opts[:current_user] &&
-      TodosFinder.new(opts[:current_user]).execute.exists?(target: opts[:noteable])
+    condition do
+      current_user &&
+      TodosFinder.new(current_user).execute.exists?(target: noteable)
     end
     command :done do
       @updates[:todo_event] = 'done'
     end
 
     desc 'Subscribe'
-    condition ->(opts) do
-      opts[:noteable] &&
-      opts[:current_user] &&
-      opts[:noteable].persisted? &&
-      !opts[:noteable].subscribed?(opts[:current_user])
+    condition do
+      noteable.persisted? &&
+      !noteable.subscribed?(current_user)
     end
     command :subscribe do
       @updates[:subscription_event] = 'subscribe'
     end
 
     desc 'Unsubscribe'
-    condition ->(opts) do
-      opts[:noteable] &&
-      opts[:current_user] &&
-      opts[:noteable].persisted? &&
-      opts[:noteable].subscribed?(opts[:current_user])
+    condition do
+      noteable.persisted? &&
+      noteable.subscribed?(current_user)
     end
     command :unsubscribe do
       @updates[:subscription_event] = 'unsubscribe'
@@ -207,12 +175,9 @@ module SlashCommands
 
     desc 'Set due date'
     params 'a date in natural language'
-    condition ->(opts) do
-      opts[:noteable] &&
-      opts[:noteable].respond_to?(:due_date) &&
-      opts[:current_user] &&
-      opts[:project] &&
-      opts[:current_user].can?(:"update_#{opts[:noteable].to_ability_name}", opts[:project])
+    condition do
+      noteable.respond_to?(:due_date) &&
+      current_user.can?(:"update_#{noteable.to_ability_name}", project)
     end
     command :due_date, :due do |due_date_param|
       due_date = Chronic.parse(due_date_param).try(:to_date)
@@ -221,13 +186,10 @@ module SlashCommands
     end
 
     desc 'Remove due date'
-    condition ->(opts) do
-      opts[:noteable] &&
-      opts[:noteable].respond_to?(:due_date) &&
-      opts[:noteable].due_date? &&
-      opts[:current_user] &&
-      opts[:project] &&
-      opts[:current_user].can?(:"update_#{opts[:noteable].to_ability_name}", opts[:project])
+    condition do
+      noteable.respond_to?(:due_date) &&
+      noteable.due_date? &&
+      current_user.can?(:"update_#{noteable.to_ability_name}", project)
     end
     command :clear_due_date do
       @updates[:due_date] = nil
@@ -236,10 +198,7 @@ module SlashCommands
     # This is a dummy command, so that it appears in the autocomplete commands
     desc 'CC'
     params '@user'
-    noop true
-    command :cc do
-      return
-    end
+    command :cc, noop: true
 
     def find_label_ids(labels_param)
       extract_references(labels_param, :label).map(&:id)
diff --git a/lib/gitlab/slash_commands/dsl.rb b/lib/gitlab/slash_commands/dsl.rb
index 20e1d071d06..3affd6253e9 100644
--- a/lib/gitlab/slash_commands/dsl.rb
+++ b/lib/gitlab/slash_commands/dsl.rb
@@ -8,20 +8,27 @@ module Gitlab
       end
 
       module ClassMethods
+        # This method is used to generate the autocompletion menu
+        # It returns no-op slash commands (such as `/cc`)
         def command_definitions(opts = {})
           @command_definitions.map do |cmd_def|
-            next if cmd_def[:cond_lambda] && !cmd_def[:cond_lambda].call(opts)
+            context = OpenStruct.new(opts)
+            next if cmd_def[:cond_block] && !context.instance_exec(&cmd_def[:cond_block])
 
             cmd_def = cmd_def.dup
 
             if cmd_def[:description].present? && cmd_def[:description].respond_to?(:call)
-              cmd_def[:description] = cmd_def[:description].call(opts) rescue ''
+              cmd_def[:description] = context.instance_exec(&cmd_def[:description]) rescue ''
             end
 
             cmd_def
           end.compact
         end
 
+        # This method is used to generate a list of valid commands in the current
+        # context of `opts`.
+        # It excludes no-op slash commands (such as `/cc`).
+        # This list can then be given to `Gitlab::SlashCommands::Extractor`.
         def command_names(opts = {})
           command_definitions(opts).flat_map do |command_definition|
             next if command_definition[:noop]
@@ -30,75 +37,103 @@ module Gitlab
           end.compact
         end
 
-        # Allows to give a description to the next slash command
-        def desc(text)
-          @description = text
+        # Allows to give a description to the next slash command.
+        # This description is shown in the autocomplete menu.
+        # It accepts a block that will be evaluated with the context given to
+        # `.command_definitions` or `.command_names`.
+        #
+        # Example:
+        #
+        #   desc do
+        #     "This is a dynamic description for #{noteable.to_ability_name}"
+        #   end
+        #   command :command_key do |arguments|
+        #     # Awesome code block
+        #   end
+        def desc(text = '', &block)
+          @description = block_given? ? block : text
         end
 
-        # Allows to define params for the next slash command
+        # Allows to define params for the next slash command.
+        # These params are shown in the autocomplete menu.
+        #
+        # Example:
+        #
+        #   params "~label ~label2"
+        #   command :command_key do |arguments|
+        #     # Awesome code block
+        #   end
         def params(*params)
           @params = params
         end
 
-        # Allows to define if a command is a no-op, but should appear in autocomplete
-        def noop(noop)
-          @noop = noop
-        end
-
-        # Allows to define if a lambda to conditionally return an action
-        def condition(cond_lambda)
-          @cond_lambda = cond_lambda
-        end
-
-        # Registers a new command which is recognizeable
-        # from body of email or comment.
+        # Allows to define conditions that must be met in order for the command
+        # to be returned by `.command_names` & `.command_definitions`.
+        # It accepts a block that will be evaluated with the context given to
+        # `.command_definitions`, `.command_names`, and the actual command method.
+        #
         # Example:
         #
+        #   condition do
+        #     project.public?
+        #   end
         #   command :command_key do |arguments|
         #     # Awesome code block
         #   end
+        def condition(&block)
+          @cond_block = block
+        end
+
+        # Registers a new command which is recognizeable from body of email or
+        # comment.
+        # It accepts aliases and takes a block.
         #
+        # Example:
+        #
+        #   command :my_command, :alias_for_my_command do |arguments|
+        #     # Awesome code block
+        #   end
         def command(*command_names, &block)
+          opts = command_names.extract_options!
           command_name, *aliases = command_names
           proxy_method_name = "__#{command_name}__"
 
-          # This proxy method is needed because calling `return` from inside a
-          # block/proc, causes a `return` from the enclosing method or lambda,
-          # otherwise a LocalJumpError error is raised.
-          define_method(proxy_method_name, &block)
+          if block_given?
+            # This proxy method is needed because calling `return` from inside a
+            # block/proc, causes a `return` from the enclosing method or lambda,
+            # otherwise a LocalJumpError error is raised.
+            define_method(proxy_method_name, &block)
 
-          define_method(command_name) do |*args|
-            unless @cond_lambda.nil? || @cond_lambda.call(project: project, current_user: current_user, noteable: noteable)
-              return
+            define_method(command_name) do |*args|
+              return if @cond_block && !instance_exec(&@cond_block)
+
+              proxy_method = method(proxy_method_name)
+
+              if proxy_method.arity == -1 || proxy_method.arity == args.size
+                instance_exec(*args, &proxy_method)
+              end
             end
 
-            proxy_method = method(proxy_method_name)
-
-            if proxy_method.arity == -1 || proxy_method.arity == args.size
-              instance_exec(*args, &proxy_method)
+            private command_name
+            aliases.each do |alias_command|
+              alias_method alias_command, command_name
+              private alias_command
             end
           end
 
-          private command_name
-          aliases.each do |alias_command|
-            alias_method alias_command, command_name
-            private alias_command
-          end
-
           command_definition = {
             name: command_name,
             aliases: aliases,
             description: @description || '',
             params: @params || []
           }
-          command_definition[:noop] = @noop unless @noop.nil?
-          command_definition[:cond_lambda] = @cond_lambda unless @cond_lambda.nil?
+          command_definition[:noop] = opts[:noop] || false
+          command_definition[:cond_block] = @cond_block
           @command_definitions << command_definition
 
           @description = nil
           @params = nil
-          @noop = nil
-          @cond_lambda = nil
+          @cond_block = nil
         end
       end
     end
diff --git a/spec/lib/gitlab/slash_commands/dsl_spec.rb b/spec/lib/gitlab/slash_commands/dsl_spec.rb
index 893a7692f11..7c946313ae1 100644
--- a/spec/lib/gitlab/slash_commands/dsl_spec.rb
+++ b/spec/lib/gitlab/slash_commands/dsl_spec.rb
@@ -1,9 +1,8 @@
 require 'spec_helper'
 
 describe Gitlab::SlashCommands::Dsl do
-  COND_LAMBDA = ->(opts) { opts[:project] == 'foo' }
   before :all do
-    DummyClass = Class.new do
+    DummyClass = Struct.new(:project) do
       include Gitlab::SlashCommands::Dsl
 
       desc 'A command with no args'
@@ -21,20 +20,21 @@ describe Gitlab::SlashCommands::Dsl do
         arg1
       end
 
-      desc ->(opts) { "A dynamic description for #{opts.fetch(:noteable)}" }
+      desc do
+        "A dynamic description for #{noteable.upcase}"
+      end
       params 'The first argument', 'The second argument'
       command :two_args do |arg1, arg2|
         [arg1, arg2]
       end
 
-      noop true
-      command :cc do |*args|
-        args
-      end
+      command :cc, noop: true
 
-      condition COND_LAMBDA
-      command :cond_action do |*args|
-        args
+      condition do
+        project == 'foo'
+      end
+      command :cond_action do |arg|
+        arg
       end
 
       command :wildcard do |*args|
@@ -42,17 +42,16 @@ describe Gitlab::SlashCommands::Dsl do
       end
     end
   end
-  let(:dummy) { DummyClass.new }
 
   describe '.command_definitions' do
     let(:base_expected) do
       [
-        { name: :no_args, aliases: [:none], description: 'A command with no args', params: [] },
-        { name: :returning, aliases: [], description: 'A command returning a value', params: [] },
-        { name: :one_arg, aliases: [:once, :first], description: '', params: ['The first argument'] },
-        { name: :two_args, aliases: [], description: '', params: ['The first argument', 'The second argument'] },
-        { name: :cc, aliases: [], description: '', params: [], noop: true },
-        { name: :wildcard, aliases: [], description: '', params: [] }
+        { name: :no_args, aliases: [:none], description: 'A command with no args', params: [], noop: false, cond_block: nil },
+        { name: :returning, aliases: [], description: 'A command returning a value', params: [], noop: false, cond_block: nil },
+        { name: :one_arg, aliases: [:once, :first], description: '', params: ['The first argument'], noop: false, cond_block: nil },
+        { name: :two_args, aliases: [], description: '', params: ['The first argument', 'The second argument'], noop: false, cond_block: nil },
+        { name: :cc, aliases: [], description: '', params: [], noop: true, cond_block: nil },
+        { name: :wildcard, aliases: [], description: '', params: [], noop: false, cond_block: nil}
       ]
     end
 
@@ -62,7 +61,7 @@ describe Gitlab::SlashCommands::Dsl do
 
     context 'with options passed' do
       context 'when condition is met' do
-        let(:expected) { base_expected << { name: :cond_action, aliases: [], description: '', params: [], cond_lambda: COND_LAMBDA } }
+        let(:expected) { base_expected << { name: :cond_action, aliases: [], description: '', params: [], noop: false, cond_block: a_kind_of(Proc) } }
 
         it 'returns an array with commands definitions' do
           expect(DummyClass.command_definitions(project: 'foo')).to match_array expected
@@ -77,7 +76,7 @@ describe Gitlab::SlashCommands::Dsl do
 
       context 'when description can be generated dynamically' do
         it 'returns an array with commands definitions with dynamic descriptions' do
-          base_expected[3][:description] = 'A dynamic description for merge request'
+          base_expected[3][:description] = 'A dynamic description for MERGE REQUEST'
 
           expect(DummyClass.command_definitions(noteable: 'merge request')).to match_array base_expected
         end
@@ -114,6 +113,8 @@ describe Gitlab::SlashCommands::Dsl do
     end
   end
 
+  let(:dummy) { DummyClass.new(nil) }
+
   describe 'command with no args' do
     context 'called with no args' do
       it 'succeeds' do
@@ -146,6 +147,28 @@ describe Gitlab::SlashCommands::Dsl do
     end
   end
 
+  describe 'noop command' do
+    it 'is not meant to be called directly' do
+      expect { dummy.__send__(:cc) }.to raise_error(NoMethodError)
+    end
+  end
+
+  describe 'command with condition' do
+    context 'when condition is not met' do
+      it 'returns nil' do
+        expect(dummy.__send__(:cond_action)).to be_nil
+      end
+    end
+
+    context 'when condition is met' do
+      let(:dummy) { DummyClass.new('foo') }
+
+      it 'succeeds' do
+        expect(dummy.__send__(:cond_action, 42)).to eq 42
+      end
+    end
+  end
+
   describe 'command with wildcard' do
     context 'called with no args' do
       it 'succeeds' do

From aadc5062ebe755aaf3fbb27fdd0af093770c9ce8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Coutable?= <remy@rymai.me>
Date: Thu, 11 Aug 2016 19:00:06 +0200
Subject: [PATCH 09/25] New TodoService#todo_exists? method
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Rémy Coutable <remy@rymai.me>
---
 app/services/slash_commands/interpret_service.rb |  4 ++--
 app/services/todo_service.rb                     |  4 ++++
 spec/lib/gitlab/slash_commands/dsl_spec.rb       |  2 +-
 spec/services/todo_service_spec.rb               | 12 ++++++++++++
 4 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/app/services/slash_commands/interpret_service.rb b/app/services/slash_commands/interpret_service.rb
index ae22ed6b845..f8aeefbfbce 100644
--- a/app/services/slash_commands/interpret_service.rb
+++ b/app/services/slash_commands/interpret_service.rb
@@ -140,7 +140,7 @@ module SlashCommands
     condition do
       noteable.persisted? &&
       current_user &&
-      !TodosFinder.new(current_user).execute.exists?(target: noteable)
+      !TodoService.new.todo_exist?(noteable, current_user)
     end
     command :todo do
       @updates[:todo_event] = 'add'
@@ -149,7 +149,7 @@ module SlashCommands
     desc 'Mark todo as done'
     condition do
       current_user &&
-      TodosFinder.new(current_user).execute.exists?(target: noteable)
+      TodoService.new.todo_exist?(noteable, current_user)
     end
     command :done do
       @updates[:todo_event] = 'done'
diff --git a/app/services/todo_service.rb b/app/services/todo_service.rb
index 6b48d68cccb..db1578d1dc4 100644
--- a/app/services/todo_service.rb
+++ b/app/services/todo_service.rb
@@ -154,6 +154,10 @@ class TodoService
     create_todos(current_user, attributes)
   end
 
+  def todo_exist?(issuable, current_user)
+    TodosFinder.new(current_user).execute.exists?(target: issuable)
+  end
+
   private
 
   def create_todos(users, attributes)
diff --git a/spec/lib/gitlab/slash_commands/dsl_spec.rb b/spec/lib/gitlab/slash_commands/dsl_spec.rb
index 7c946313ae1..385f534ad6f 100644
--- a/spec/lib/gitlab/slash_commands/dsl_spec.rb
+++ b/spec/lib/gitlab/slash_commands/dsl_spec.rb
@@ -51,7 +51,7 @@ describe Gitlab::SlashCommands::Dsl do
         { name: :one_arg, aliases: [:once, :first], description: '', params: ['The first argument'], noop: false, cond_block: nil },
         { name: :two_args, aliases: [], description: '', params: ['The first argument', 'The second argument'], noop: false, cond_block: nil },
         { name: :cc, aliases: [], description: '', params: [], noop: true, cond_block: nil },
-        { name: :wildcard, aliases: [], description: '', params: [], noop: false, cond_block: nil}
+        { name: :wildcard, aliases: [], description: '', params: [], noop: false, cond_block: nil }
       ]
     end
 
diff --git a/spec/services/todo_service_spec.rb b/spec/services/todo_service_spec.rb
index 34d8ea9090e..4c41df0d4f5 100644
--- a/spec/services/todo_service_spec.rb
+++ b/spec/services/todo_service_spec.rb
@@ -290,6 +290,18 @@ describe TodoService, services: true do
         should_create_todo(user: author, target: unassigned_issue, action: Todo::MARKED)
       end
     end
+
+    describe '#todo_exists?' do
+      it 'returns false when no todo exist for the given issuable' do
+        expect(service.todo_exist?(unassigned_issue, author)).to be_falsy
+      end
+
+      it 'returns true when a todo exist for the given issuable' do
+        service.mark_todo(unassigned_issue, author)
+
+        expect(service.todo_exist?(unassigned_issue, author)).to be_truthy
+      end
+    end
   end
 
   describe 'Merge Requests' do

From f393f2dde016edf63b5168eb63405f15d65803eb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Coutable?= <remy@rymai.me>
Date: Fri, 12 Aug 2016 11:19:29 +0200
Subject: [PATCH 10/25] Simplify the slash commands DSL to store action blocks
 instead of creating methods
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Other improvements:
- Ensure slash commands autocomplete doesn't break when noteable_type is not given
- Slash commands: improve autocomplete behavior and /due command
- We don't display slash commands for note edit forms.
- Add tests for reply by email with slash commands
- Be sure to execute slash commands after the note creation in Notes::CreateService

Signed-off-by: Rémy Coutable <remy@rymai.me>
---
 .../javascripts/gfm_auto_complete.js.es6      |   4 +-
 app/controllers/projects_controller.rb        |   8 +-
 app/services/issuable_base_service.rb         |   4 +-
 app/services/notes/create_service.rb          |   5 +-
 app/services/notes/slash_commands_service.rb  |  15 +-
 app/services/projects/autocomplete_service.rb |  34 ++--
 app/services/projects/participants_service.rb |  25 +--
 .../slash_commands/interpret_service.rb       |  33 ++--
 .../layouts/_init_auto_complete.html.haml     |   2 +-
 doc/workflow/slash_commands.md                |   2 +-
 lib/gitlab/slash_commands/dsl.rb              |  88 ++++++-----
 .../issues/user_uses_slash_commands_spec.rb   |   1 -
 spec/fixtures/emails/commands_in_reply.eml    |  43 +++++
 spec/fixtures/emails/commands_only_reply.eml  |   1 +
 .../email/handler/create_note_handler_spec.rb |  45 +++++-
 spec/lib/gitlab/slash_commands/dsl_spec.rb    | 147 +++++++++++-------
 16 files changed, 297 insertions(+), 160 deletions(-)
 create mode 100644 spec/fixtures/emails/commands_in_reply.eml

diff --git a/app/assets/javascripts/gfm_auto_complete.js.es6 b/app/assets/javascripts/gfm_auto_complete.js.es6
index 21639c7c084..9be32ed5937 100644
--- a/app/assets/javascripts/gfm_auto_complete.js.es6
+++ b/app/assets/javascripts/gfm_auto_complete.js.es6
@@ -249,7 +249,8 @@
           }
         }
       });
-      return this.input.atwho({
+      // We don't instantiate the slash commands autocomplete for note edit forms
+      $("form:not(.edit-note) .js-gfm-input").atwho({
         at: '/',
         alias: 'commands',
         displayTpl: function(value) {
@@ -284,6 +285,7 @@
           beforeInsert: this.DefaultOptions.beforeInsert
         }
       });
+      return;
     },
     destroyAtWho: function() {
       return this.input.atwho('destroy');
diff --git a/app/controllers/projects_controller.rb b/app/controllers/projects_controller.rb
index af20984cbe7..9c387fd3daa 100644
--- a/app/controllers/projects_controller.rb
+++ b/app/controllers/projects_controller.rb
@@ -134,10 +134,8 @@ class ProjectsController < Projects::ApplicationController
   end
 
   def autocomplete_sources
-    note_type = params['type']
-    note_id = params['type_id']
-    autocomplete = ::Projects::AutocompleteService.new(@project, current_user)
-    participants = ::Projects::ParticipantsService.new(@project, current_user).execute(note_type, note_id)
+    autocomplete = ::Projects::AutocompleteService.new(@project, current_user, params)
+    participants = ::Projects::ParticipantsService.new(@project, current_user, params).execute
 
     @suggestions = {
       emojis: Gitlab::AwardEmoji.urls,
@@ -146,7 +144,7 @@ class ProjectsController < Projects::ApplicationController
       mergerequests: autocomplete.merge_requests,
       labels: autocomplete.labels,
       members: participants,
-      commands: autocomplete.commands(note_type, note_id)
+      commands: autocomplete.commands
     }
 
     respond_to do |format|
diff --git a/app/services/issuable_base_service.rb b/app/services/issuable_base_service.rb
index c14bda811c2..1a01b333366 100644
--- a/app/services/issuable_base_service.rb
+++ b/app/services/issuable_base_service.rb
@@ -94,10 +94,10 @@ class IssuableBaseService < BaseService
   end
 
   def merge_slash_commands_into_params!(issuable)
-    command_params = SlashCommands::InterpretService.new(project, current_user).
+    commands = SlashCommands::InterpretService.new(project, current_user).
       execute(params[:description], issuable)
 
-    params.merge!(command_params)
+    params.merge!(commands)
   end
 
   def create_issuable(issuable, attributes)
diff --git a/app/services/notes/create_service.rb b/app/services/notes/create_service.rb
index 0c2513409a1..1b2d63034b8 100644
--- a/app/services/notes/create_service.rb
+++ b/app/services/notes/create_service.rb
@@ -14,7 +14,8 @@ module Notes
       # We execute commands (extracted from `params[:note]`) on the noteable
       # **before** we save the note because if the note consists of commands
       # only, there is no need be create a note!
-      commands_executed = SlashCommandsService.new(project, current_user).execute(note)
+      slash_commands_service = SlashCommandsService.new(project, current_user)
+      commands = slash_commands_service.extract_commands(note)
 
       if note.save
         # Finish the harder work in the background
@@ -24,7 +25,7 @@ module Notes
 
       # We must add the error after we call #save because errors are reset
       # when #save is called
-      if commands_executed && note.note.blank?
+      if slash_commands_service.execute(commands, note) && note.note.blank?
         note.errors.add(:commands_only, 'Your commands are being executed.')
       end
 
diff --git a/app/services/notes/slash_commands_service.rb b/app/services/notes/slash_commands_service.rb
index 54d43d06466..ebced9577d8 100644
--- a/app/services/notes/slash_commands_service.rb
+++ b/app/services/notes/slash_commands_service.rb
@@ -6,16 +6,19 @@ module Notes
       'MergeRequest' => MergeRequests::UpdateService
     }
 
-    def execute(note)
-      noteable_update_service = UPDATE_SERVICES[note.noteable_type]
-      return false unless noteable_update_service
-      return false unless can?(current_user, :"update_#{note.noteable_type.underscore}", note.noteable)
+    def extract_commands(note)
+      @noteable_update_service = UPDATE_SERVICES[note.noteable_type]
+      return [] unless @noteable_update_service
+      return [] unless can?(current_user, :"update_#{note.noteable_type.underscore}", note.noteable)
 
-      commands = SlashCommands::InterpretService.new(project, current_user).
+      SlashCommands::InterpretService.new(project, current_user).
         execute(note.note, note.noteable)
+    end
 
+    def execute(commands, note)
       if commands.any?
-        noteable_update_service.new(project, current_user, commands).execute(note.noteable)
+        @noteable_update_service.new(project, current_user, commands).
+          execute(note.noteable)
       end
     end
   end
diff --git a/app/services/projects/autocomplete_service.rb b/app/services/projects/autocomplete_service.rb
index 779f64f584e..477c999eff4 100644
--- a/app/services/projects/autocomplete_service.rb
+++ b/app/services/projects/autocomplete_service.rb
@@ -16,26 +16,34 @@ module Projects
       @project.labels.select([:title, :color])
     end
 
-    def commands(noteable_type, noteable_id)
+    def commands
+      # We don't return commands when editing an issue or merge request
+      # This should be improved by not enabling autocomplete at the JS-level
+      # following this suggestion: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5021#note_13837384
+      return [] if !target || %w[edit update].include?(params[:action_name])
+
       SlashCommands::InterpretService.command_definitions(
-        project: @project,
-        noteable: command_target(noteable_type, noteable_id),
+        project: project,
+        noteable: target,
         current_user: current_user
       )
     end
 
     private
 
-    def command_target(noteable_type, noteable_id)
-      case noteable_type
-      when 'Issue'
-        IssuesFinder.new(current_user, project_id: @project.id, state: 'all').
-          execute.find_or_initialize_by(iid: noteable_id)
-      when 'MergeRequest'
-        MergeRequestsFinder.new(current_user, project_id: @project.id, state: 'all').
-          execute.find_or_initialize_by(iid: noteable_id)
-      else
-        nil
+    def target
+      @target ||= begin
+        noteable_id = params[:type_id]
+        case params[:type]
+        when 'Issue'
+          IssuesFinder.new(current_user, project_id: project.id, state: 'all').
+            execute.find_or_initialize_by(iid: noteable_id)
+        when 'MergeRequest'
+          MergeRequestsFinder.new(current_user, project_id: project.id, state: 'all').
+            execute.find_or_initialize_by(iid: noteable_id)
+        else
+          nil
+        end
       end
     end
   end
diff --git a/app/services/projects/participants_service.rb b/app/services/projects/participants_service.rb
index 02c4eee3d02..1c8f2913e8b 100644
--- a/app/services/projects/participants_service.rb
+++ b/app/services/projects/participants_service.rb
@@ -1,8 +1,11 @@
 module Projects
   class ParticipantsService < BaseService
-    def execute(noteable_type, noteable_id)
-      @noteable_type = noteable_type
-      @noteable_id = noteable_id
+    attr_reader :noteable_type, :noteable_id
+
+    def execute
+      @noteable_type = params[:type]
+      @noteable_id = params[:type_id]
+
       project_members = sorted(project.team.members)
       participants = target_owner + participants_in_target + all_members + groups + project_members
       participants.uniq
@@ -10,13 +13,15 @@ module Projects
 
     def target
       @target ||=
-        case @noteable_type
-        when "Issue"
-          project.issues.find_by_iid(@noteable_id)
-        when "MergeRequest"
-          project.merge_requests.find_by_iid(@noteable_id)
-        when "Commit"
-          project.commit(@noteable_id)
+        case noteable_type
+        when 'Issue'
+          IssuesFinder.new(current_user, project_id: project.id, state: 'all').
+            execute.find_by(iid: noteable_id)
+        when 'MergeRequest'
+          MergeRequestsFinder.new(current_user, project_id: project.id, state: 'all').
+            execute.find_by(iid: noteable_id)
+        when 'Commit'
+          project.commit(noteable_id)
         else
           nil
         end
diff --git a/app/services/slash_commands/interpret_service.rb b/app/services/slash_commands/interpret_service.rb
index f8aeefbfbce..112bebe423a 100644
--- a/app/services/slash_commands/interpret_service.rb
+++ b/app/services/slash_commands/interpret_service.rb
@@ -11,8 +11,8 @@ module SlashCommands
       @updates = {}
 
       commands = extractor(noteable: noteable).extract_commands!(content)
-      commands.each do |command|
-        __send__(*command)
+      commands.each do |command, *args|
+        execute_command(command, *args)
       end
 
       @updates
@@ -30,8 +30,9 @@ module SlashCommands
       "Close this #{noteable.to_ability_name.humanize(capitalize: false)}"
     end
     condition do
+      noteable.persisted? &&
       noteable.open? &&
-      current_user.can?(:"update_#{noteable.to_ability_name}", project)
+      current_user.can?(:"update_#{noteable.to_ability_name}", noteable)
     end
     command :close do
       @updates[:state_event] = 'close'
@@ -42,7 +43,7 @@ module SlashCommands
     end
     condition do
       noteable.closed? &&
-      current_user.can?(:"update_#{noteable.to_ability_name}", project)
+      current_user.can?(:"update_#{noteable.to_ability_name}", noteable)
     end
     command :open, :reopen do
       @updates[:state_event] = 'reopen'
@@ -52,7 +53,7 @@ module SlashCommands
     params '<New title>'
     condition do
       noteable.persisted? &&
-      current_user.can?(:"update_#{noteable.to_ability_name}", project)
+      current_user.can?(:"update_#{noteable.to_ability_name}", noteable)
     end
     command :title do |title_param|
       @updates[:title] = title_param
@@ -65,9 +66,8 @@ module SlashCommands
     end
     command :assign, :reassign do |assignee_param|
       user = extract_references(assignee_param, :user).first
-      return unless user
 
-      @updates[:assignee_id] = user.id
+      @updates[:assignee_id] = user.id if user
     end
 
     desc 'Remove assignee'
@@ -87,9 +87,8 @@ module SlashCommands
     end
     command :milestone do |milestone_param|
       milestone = extract_references(milestone_param, :milestone).first
-      return unless milestone
 
-      @updates[:milestone_id] = milestone.id
+      @updates[:milestone_id] = milestone.id if milestone
     end
 
     desc 'Remove milestone'
@@ -109,9 +108,8 @@ module SlashCommands
     end
     command :label, :labels do |labels_param|
       label_ids = find_label_ids(labels_param)
-      return if label_ids.empty?
 
-      @updates[:add_label_ids] = label_ids
+      @updates[:add_label_ids] = label_ids unless label_ids.empty?
     end
 
     desc 'Remove label(s)'
@@ -122,9 +120,8 @@ module SlashCommands
     end
     command :unlabel, :remove_label, :remove_labels do |labels_param|
       label_ids = find_label_ids(labels_param)
-      return if label_ids.empty?
 
-      @updates[:remove_label_ids] = label_ids
+      @updates[:remove_label_ids] = label_ids unless label_ids.empty?
     end
 
     desc 'Remove all labels'
@@ -139,7 +136,6 @@ module SlashCommands
     desc 'Add a todo'
     condition do
       noteable.persisted? &&
-      current_user &&
       !TodoService.new.todo_exist?(noteable, current_user)
     end
     command :todo do
@@ -148,7 +144,6 @@ module SlashCommands
 
     desc 'Mark todo as done'
     condition do
-      current_user &&
       TodoService.new.todo_exist?(noteable, current_user)
     end
     command :done do
@@ -174,12 +169,12 @@ module SlashCommands
     end
 
     desc 'Set due date'
-    params 'a date in natural language'
+    params '<in 2 days | this Friday | December 31st>'
     condition do
       noteable.respond_to?(:due_date) &&
-      current_user.can?(:"update_#{noteable.to_ability_name}", project)
+      current_user.can?(:"update_#{noteable.to_ability_name}", noteable)
     end
-    command :due_date, :due do |due_date_param|
+    command :due, :due_date do |due_date_param|
       due_date = Chronic.parse(due_date_param).try(:to_date)
 
       @updates[:due_date] = due_date if due_date
@@ -189,7 +184,7 @@ module SlashCommands
     condition do
       noteable.respond_to?(:due_date) &&
       noteable.due_date? &&
-      current_user.can?(:"update_#{noteable.to_ability_name}", project)
+      current_user.can?(:"update_#{noteable.to_ability_name}", noteable)
     end
     command :clear_due_date do
       @updates[:due_date] = nil
diff --git a/app/views/layouts/_init_auto_complete.html.haml b/app/views/layouts/_init_auto_complete.html.haml
index 351100f3523..a51347fde83 100644
--- a/app/views/layouts/_init_auto_complete.html.haml
+++ b/app/views/layouts/_init_auto_complete.html.haml
@@ -2,6 +2,6 @@
 - noteable_class = @noteable.class if @noteable.present?
 
 :javascript
-  GitLab.GfmAutoComplete.dataSource = "#{autocomplete_sources_namespace_project_path(project.namespace, project, type: noteable_class, type_id: params[:id])}"
+  GitLab.GfmAutoComplete.dataSource = "#{autocomplete_sources_namespace_project_path(project.namespace, project, type: noteable_class, type_id: params[:id], action_name: action_name)}"
   GitLab.GfmAutoComplete.cachedData = undefined;
   GitLab.GfmAutoComplete.setup();
diff --git a/doc/workflow/slash_commands.md b/doc/workflow/slash_commands.md
index c4edbeddd40..2bdc18ad248 100644
--- a/doc/workflow/slash_commands.md
+++ b/doc/workflow/slash_commands.md
@@ -25,5 +25,5 @@ do.
 | `/done`                    | None                | Mark todo as done |
 | `/subscribe`               | None                | Subscribe |
 | `/unsubscribe`             | None                | Unsubscribe |
-| `/due_date a date in natural language` | `/due`  | Set due date |
+| `/due <in 2 days | this Friday | December 31st>` | `/due_date` | Set due date |
 | `/clear_due_date`          | None                | Remove due date |
diff --git a/lib/gitlab/slash_commands/dsl.rb b/lib/gitlab/slash_commands/dsl.rb
index 3affd6253e9..ce659aff1da 100644
--- a/lib/gitlab/slash_commands/dsl.rb
+++ b/lib/gitlab/slash_commands/dsl.rb
@@ -4,20 +4,34 @@ module Gitlab
       extend ActiveSupport::Concern
 
       included do
-        @command_definitions = []
+        cattr_accessor :definitions
       end
 
-      module ClassMethods
-        # This method is used to generate the autocompletion menu
-        # It returns no-op slash commands (such as `/cc`)
+      def execute_command(name, *args)
+        name = name.to_sym
+        cmd_def = self.class.definitions.find do |cmd_def|
+          self.class.command_name_and_aliases(cmd_def).include?(name)
+        end
+        return unless cmd_def && cmd_def[:action_block]
+        return if self.class.command_unavailable?(cmd_def, self)
+
+        block_arity = cmd_def[:action_block].arity
+        if block_arity == -1 || block_arity == args.size
+          instance_exec(*args, &cmd_def[:action_block])
+        end
+      end
+
+      class_methods do
+        # This method is used to generate the autocompletion menu.
+        # It returns no-op slash commands (such as `/cc`).
         def command_definitions(opts = {})
-          @command_definitions.map do |cmd_def|
+          self.definitions.map do |cmd_def|
             context = OpenStruct.new(opts)
-            next if cmd_def[:cond_block] && !context.instance_exec(&cmd_def[:cond_block])
+            next if command_unavailable?(cmd_def, context)
 
             cmd_def = cmd_def.dup
 
-            if cmd_def[:description].present? && cmd_def[:description].respond_to?(:call)
+            if cmd_def[:description].respond_to?(:call)
               cmd_def[:description] = context.instance_exec(&cmd_def[:description]) rescue ''
             end
 
@@ -30,13 +44,24 @@ module Gitlab
         # It excludes no-op slash commands (such as `/cc`).
         # This list can then be given to `Gitlab::SlashCommands::Extractor`.
         def command_names(opts = {})
-          command_definitions(opts).flat_map do |command_definition|
-            next if command_definition[:noop]
+          self.definitions.flat_map do |cmd_def|
+            next if cmd_def[:opts].fetch(:noop, false)
 
-            [command_definition[:name], *command_definition[:aliases]]
+            context = OpenStruct.new(opts)
+            next if command_unavailable?(cmd_def, context)
+
+            command_name_and_aliases(cmd_def)
           end.compact
         end
 
+        def command_unavailable?(cmd_def, context)
+          cmd_def[:condition_block] && !context.instance_exec(&cmd_def[:condition_block])
+        end
+
+        def command_name_and_aliases(cmd_def)
+          [cmd_def[:name], *cmd_def[:aliases]]
+        end
+
         # Allows to give a description to the next slash command.
         # This description is shown in the autocomplete menu.
         # It accepts a block that will be evaluated with the context given to
@@ -81,7 +106,7 @@ module Gitlab
         #     # Awesome code block
         #   end
         def condition(&block)
-          @cond_block = block
+          @condition_block = block
         end
 
         # Registers a new command which is recognizeable from body of email or
@@ -95,45 +120,22 @@ module Gitlab
         #   end
         def command(*command_names, &block)
           opts = command_names.extract_options!
-          command_name, *aliases = command_names
-          proxy_method_name = "__#{command_name}__"
+          name, *aliases = command_names
 
-          if block_given?
-            # This proxy method is needed because calling `return` from inside a
-            # block/proc, causes a `return` from the enclosing method or lambda,
-            # otherwise a LocalJumpError error is raised.
-            define_method(proxy_method_name, &block)
-
-            define_method(command_name) do |*args|
-              return if @cond_block && !instance_exec(&@cond_block)
-
-              proxy_method = method(proxy_method_name)
-
-              if proxy_method.arity == -1 || proxy_method.arity == args.size
-                instance_exec(*args, &proxy_method)
-              end
-            end
-
-            private command_name
-            aliases.each do |alias_command|
-              alias_method alias_command, command_name
-              private alias_command
-            end
-          end
-
-          command_definition = {
-            name: command_name,
+          self.definitions ||= []
+          self.definitions << {
+            name: name,
             aliases: aliases,
             description: @description || '',
-            params: @params || []
+            params: @params || [],
+            condition_block: @condition_block,
+            action_block: block,
+            opts: opts
           }
-          command_definition[:noop] = opts[:noop] || false
-          command_definition[:cond_block] = @cond_block
-          @command_definitions << command_definition
 
           @description = nil
           @params = nil
-          @cond_block = nil
+          @condition_block = nil
         end
       end
     end
diff --git a/spec/features/issues/user_uses_slash_commands_spec.rb b/spec/features/issues/user_uses_slash_commands_spec.rb
index 47c4ce306e9..fe320070704 100644
--- a/spec/features/issues/user_uses_slash_commands_spec.rb
+++ b/spec/features/issues/user_uses_slash_commands_spec.rb
@@ -55,5 +55,4 @@ feature 'Issues > User uses slash commands', feature: true, js: true do
       end
     end
   end
-
 end
diff --git a/spec/fixtures/emails/commands_in_reply.eml b/spec/fixtures/emails/commands_in_reply.eml
new file mode 100644
index 00000000000..06bf60ab734
--- /dev/null
+++ b/spec/fixtures/emails/commands_in_reply.eml
@@ -0,0 +1,43 @@
+Return-Path: <jake@adventuretime.ooo>
+Received: from iceking.adventuretime.ooo ([unix socket]) by iceking (Cyrus v2.2.13-Debian-2.2.13-19+squeeze3) with LMTPA; Thu, 13 Jun 2013 17:03:50 -0400
+Received: from mail-ie0-x234.google.com (mail-ie0-x234.google.com [IPv6:2607:f8b0:4001:c03::234]) by iceking.adventuretime.ooo (8.14.3/8.14.3/Debian-9.4) with ESMTP id r5DL3nFJ016967 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=NOT) for <reply+59d8df8370b7e95c5a49fbf86aeb2c93@appmail.adventuretime.ooo>; Thu, 13 Jun 2013 17:03:50 -0400
+Received: by mail-ie0-f180.google.com with SMTP id f4so21977375iea.25 for <reply+59d8df8370b7e95c5a49fbf86aeb2c93@appmail.adventuretime.ooo>; Thu, 13 Jun 2013 14:03:48 -0700
+Received: by 10.0.0.1 with HTTP; Thu, 13 Jun 2013 14:03:48 -0700
+Date: Thu, 13 Jun 2013 17:03:48 -0400
+From: Jake the Dog <jake@adventuretime.ooo>
+To: reply+59d8df8370b7e95c5a49fbf86aeb2c93@appmail.adventuretime.ooo
+Message-ID: <CADkmRc+rNGAGGbV2iE5p918UVy4UyJqVcXRO2=otppgzduJSg@mail.gmail.com>
+In-Reply-To: <issue_1@localhost>
+References: <issue_1@localhost> <reply-59d8df8370b7e95c5a49fbf86aeb2c93@localhost>
+Subject: re: [Discourse Meta] eviltrout posted in 'Adventure Time Sux'
+Mime-Version: 1.0
+Content-Type: text/plain;
+ charset=ISO-8859-1
+Content-Transfer-Encoding: 7bit
+X-Sieve: CMU Sieve 2.2
+X-Received: by 10.0.0.1 with SMTP id n7mr11234144ipb.85.1371157428600; Thu,
+ 13 Jun 2013 14:03:48 -0700 (PDT)
+X-Scanned-By: MIMEDefang 2.69 on IPv6:2001:470:1d:165::1
+
+Cool!
+
+/close
+/todo
+/due tomorrow
+
+
+On Sun, Jun 9, 2013 at 1:39 PM, eviltrout via Discourse Meta
+<reply+59d8df8370b7e95c5a49fbf86aeb2c93@appmail.adventuretime.ooo> wrote:
+>
+>
+>
+> eviltrout posted in 'Adventure Time Sux' on Discourse Meta:
+>
+> ---
+> hey guys everyone knows adventure time sucks!
+>
+> ---
+> Please visit this link to respond: http://localhost:3000/t/adventure-time-sux/1234/3
+>
+> To unsubscribe from these emails, visit your [user preferences](http://localhost:3000/user_preferences).
+>
diff --git a/spec/fixtures/emails/commands_only_reply.eml b/spec/fixtures/emails/commands_only_reply.eml
index ccd92e406c4..aed64224b06 100644
--- a/spec/fixtures/emails/commands_only_reply.eml
+++ b/spec/fixtures/emails/commands_only_reply.eml
@@ -21,6 +21,7 @@ X-Scanned-By: MIMEDefang 2.69 on IPv6:2001:470:1d:165::1
 
 /close
 /todo
+/due tomorrow
 
 
 On Sun, Jun 9, 2013 at 1:39 PM, eviltrout via Discourse Meta
diff --git a/spec/lib/gitlab/email/handler/create_note_handler_spec.rb b/spec/lib/gitlab/email/handler/create_note_handler_spec.rb
index afb072105cf..4909fed6b77 100644
--- a/spec/lib/gitlab/email/handler/create_note_handler_spec.rb
+++ b/spec/lib/gitlab/email/handler/create_note_handler_spec.rb
@@ -75,13 +75,54 @@ describe Gitlab::Email::Handler::CreateNoteHandler, lib: true do
           project.team << [user, :developer]
         end
 
-        it 'raises a CommandsOnlyNoteError' do
-          expect { receiver.execute }.not_to raise_error
+        it 'does not raise an error' do
+          expect(TodoService.new.todo_exist?(noteable, user)).to be_falsy
+
+          # One system note is created for the 'close' event
+          expect { receiver.execute }.to change { noteable.notes.count }.by(1)
+
+          expect(noteable.reload).to be_closed
+          expect(noteable.due_date).to eq(Date.tomorrow)
+          expect(TodoService.new.todo_exist?(noteable, user)).to be_truthy
         end
       end
     end
   end
 
+  context 'when the note contains slash commands' do
+    let!(:email_raw) { fixture_file("emails/commands_in_reply.eml") }
+
+    context 'and current user cannot update noteable' do
+      it 'post a note and does not update the noteable' do
+        expect(TodoService.new.todo_exist?(noteable, user)).to be_falsy
+
+        # One system note is created for the new note
+        expect { receiver.execute }.to change { noteable.notes.count }.by(1)
+
+        expect(noteable.reload).to be_open
+        expect(noteable.due_date).to be_nil
+        expect(TodoService.new.todo_exist?(noteable, user)).to be_falsy
+      end
+    end
+
+    context 'and current user can update noteable' do
+      before do
+        project.team << [user, :developer]
+      end
+
+      it 'post a note and updates the noteable' do
+        expect(TodoService.new.todo_exist?(noteable, user)).to be_falsy
+
+        # One system note is created for the new note, one for the 'close' event
+        expect { receiver.execute }.to change { noteable.notes.count }.by(2)
+
+        expect(noteable.reload).to be_closed
+        expect(noteable.due_date).to eq(Date.tomorrow)
+        expect(TodoService.new.todo_exist?(noteable, user)).to be_truthy
+      end
+    end
+  end
+
   context "when the reply is blank" do
     let!(:email_raw) { fixture_file("emails/no_content_reply.eml") }
 
diff --git a/spec/lib/gitlab/slash_commands/dsl_spec.rb b/spec/lib/gitlab/slash_commands/dsl_spec.rb
index 385f534ad6f..500ff3ca1fe 100644
--- a/spec/lib/gitlab/slash_commands/dsl_spec.rb
+++ b/spec/lib/gitlab/slash_commands/dsl_spec.rb
@@ -46,12 +46,42 @@ describe Gitlab::SlashCommands::Dsl do
   describe '.command_definitions' do
     let(:base_expected) do
       [
-        { name: :no_args, aliases: [:none], description: 'A command with no args', params: [], noop: false, cond_block: nil },
-        { name: :returning, aliases: [], description: 'A command returning a value', params: [], noop: false, cond_block: nil },
-        { name: :one_arg, aliases: [:once, :first], description: '', params: ['The first argument'], noop: false, cond_block: nil },
-        { name: :two_args, aliases: [], description: '', params: ['The first argument', 'The second argument'], noop: false, cond_block: nil },
-        { name: :cc, aliases: [], description: '', params: [], noop: true, cond_block: nil },
-        { name: :wildcard, aliases: [], description: '', params: [], noop: false, cond_block: nil }
+        {
+          name: :no_args, aliases: [:none],
+          description: 'A command with no args', params: [],
+          condition_block: nil, action_block: a_kind_of(Proc),
+          opts: {}
+        },
+        {
+          name: :returning, aliases: [],
+          description: 'A command returning a value', params: [],
+          condition_block: nil, action_block: a_kind_of(Proc),
+          opts: {}
+        },
+        {
+          name: :one_arg, aliases: [:once, :first],
+          description: '', params: ['The first argument'],
+          condition_block: nil, action_block: a_kind_of(Proc),
+          opts: {}
+        },
+        {
+          name: :two_args, aliases: [],
+          description: '', params: ['The first argument', 'The second argument'],
+          condition_block: nil, action_block: a_kind_of(Proc),
+          opts: {}
+        },
+        {
+          name: :cc, aliases: [],
+          description: '', params: [],
+          condition_block: nil, action_block: nil,
+          opts: { noop: true }
+        },
+        {
+          name: :wildcard, aliases: [],
+          description: '', params: [],
+          condition_block: nil, action_block: a_kind_of(Proc),
+          opts: {}
+        }
       ]
     end
 
@@ -61,7 +91,14 @@ describe Gitlab::SlashCommands::Dsl do
 
     context 'with options passed' do
       context 'when condition is met' do
-        let(:expected) { base_expected << { name: :cond_action, aliases: [], description: '', params: [], noop: false, cond_block: a_kind_of(Proc) } }
+        let(:expected) do
+          base_expected << {
+            name: :cond_action, aliases: [],
+            description: '', params: [],
+            condition_block: a_kind_of(Proc), action_block: a_kind_of(Proc),
+            opts: {}
+          }
+        end
 
         it 'returns an array with commands definitions' do
           expect(DummyClass.command_definitions(project: 'foo')).to match_array expected
@@ -115,76 +152,78 @@ describe Gitlab::SlashCommands::Dsl do
 
   let(:dummy) { DummyClass.new(nil) }
 
-  describe 'command with no args' do
-    context 'called with no args' do
-      it 'succeeds' do
-        expect(dummy.__send__(:no_args)).to eq 'Hello World!'
+  describe '#execute_command' do
+    describe 'command with no args' do
+      context 'called with no args' do
+        it 'succeeds' do
+          expect(dummy.execute_command(:no_args)).to eq 'Hello World!'
+        end
       end
     end
-  end
 
-  describe 'command with an explicit return' do
-    context 'called with no args' do
-      it 'succeeds' do
-        expect(dummy.__send__(:returning)).to eq 42
+    describe 'command with an explicit return' do
+      context 'called with no args' do
+        it 'succeeds' do
+          expect { dummy.execute_command(:returning) }.to raise_error(LocalJumpError)
+        end
       end
     end
-  end
 
-  describe 'command with one arg' do
-    context 'called with one arg' do
-      it 'succeeds' do
-        expect(dummy.__send__(:one_arg, 42)).to eq 42
+    describe 'command with one arg' do
+      context 'called with one arg' do
+        it 'succeeds' do
+          expect(dummy.execute_command(:one_arg, 42)).to eq 42
+        end
       end
     end
-  end
 
-  describe 'command with two args' do
-    context 'called with two args' do
-      it 'succeeds' do
-        expect(dummy.__send__(:two_args, 42, 'foo')).to eq [42, 'foo']
+    describe 'command with two args' do
+      context 'called with two args' do
+        it 'succeeds' do
+          expect(dummy.execute_command(:two_args, 42, 'foo')).to eq [42, 'foo']
+        end
       end
     end
-  end
 
-  describe 'noop command' do
-    it 'is not meant to be called directly' do
-      expect { dummy.__send__(:cc) }.to raise_error(NoMethodError)
-    end
-  end
-
-  describe 'command with condition' do
-    context 'when condition is not met' do
+    describe 'noop command' do
       it 'returns nil' do
-        expect(dummy.__send__(:cond_action)).to be_nil
+        expect(dummy.execute_command(:cc)).to be_nil
       end
     end
 
-    context 'when condition is met' do
-      let(:dummy) { DummyClass.new('foo') }
-
-      it 'succeeds' do
-        expect(dummy.__send__(:cond_action, 42)).to eq 42
+    describe 'command with condition' do
+      context 'when condition is not met' do
+        it 'returns nil' do
+          expect(dummy.execute_command(:cond_action)).to be_nil
+        end
       end
-    end
-  end
 
-  describe 'command with wildcard' do
-    context 'called with no args' do
-      it 'succeeds' do
-        expect(dummy.__send__(:wildcard)).to eq []
+      context 'when condition is met' do
+        let(:dummy) { DummyClass.new('foo') }
+
+        it 'succeeds' do
+          expect(dummy.execute_command(:cond_action, 42)).to eq 42
+        end
       end
     end
 
-    context 'called with one arg' do
-      it 'succeeds' do
-        expect(dummy.__send__(:wildcard, 42)).to eq [42]
+    describe 'command with wildcard' do
+      context 'called with no args' do
+        it 'succeeds' do
+          expect(dummy.execute_command(:wildcard)).to eq []
+        end
       end
-    end
 
-    context 'called with two args' do
-      it 'succeeds' do
-        expect(dummy.__send__(:wildcard, 42, 'foo')).to eq [42, 'foo']
+      context 'called with one arg' do
+        it 'succeeds' do
+          expect(dummy.execute_command(:wildcard, 42)).to eq [42]
+        end
+      end
+
+      context 'called with two args' do
+        it 'succeeds' do
+          expect(dummy.execute_command(:wildcard, 42, 'foo')).to eq [42, 'foo']
+        end
       end
     end
   end

From 5d4993d62357e438b6211247278025040f3ae382 Mon Sep 17 00:00:00 2001
From: Douwe Maan <douwe@selenight.nl>
Date: Fri, 12 Aug 2016 18:16:36 -0500
Subject: [PATCH 11/25] Only autocomplete commands at the beginning of a line

---
 app/assets/javascripts/gfm_auto_complete.js.es6 | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/app/assets/javascripts/gfm_auto_complete.js.es6 b/app/assets/javascripts/gfm_auto_complete.js.es6
index 9be32ed5937..2e1cbb362a3 100644
--- a/app/assets/javascripts/gfm_auto_complete.js.es6
+++ b/app/assets/javascripts/gfm_auto_complete.js.es6
@@ -268,7 +268,7 @@
           return _.template(tpl)(value);
         },
         insertTpl: function(value) {
-          var tpl = "\n/${name} ";
+          var tpl = "/${name} ";
           var reference_prefix = null;
           if (value.params.length > 0) {
             reference_prefix = value.params[0][0];
@@ -282,7 +282,16 @@
         callbacks: {
           sorter: this.DefaultOptions.sorter,
           filter: this.DefaultOptions.filter,
-          beforeInsert: this.DefaultOptions.beforeInsert
+          beforeInsert: this.DefaultOptions.beforeInsert,
+          matcher: function(flag, subtext, should_startWithSpace, acceptSpaceBar) {
+            var regexp = /(?:^|\n)\/([A-Za-z_]*)$/gi
+            var match = regexp.exec(subtext);
+            if (match) {
+              return match[1];
+            } else {
+              return null;
+            }
+          }
         }
       });
       return;

From 5a07b760dff04660d9c7da84852c710b1fc2f786 Mon Sep 17 00:00:00 2001
From: Douwe Maan <douwe@selenight.nl>
Date: Fri, 12 Aug 2016 20:17:18 -0500
Subject: [PATCH 12/25] Refactor slash command definition

---
 app/controllers/projects_controller.rb        | 20 ++++-
 app/services/issuable_base_service.rb         |  7 +-
 app/services/notes/create_service.rb          |  6 +-
 app/services/notes/slash_commands_service.rb  | 11 ++-
 app/services/projects/autocomplete_service.rb | 48 +++++------
 app/services/projects/participants_service.rb | 41 +++-------
 .../slash_commands/interpret_service.rb       | 24 ++++--
 .../slash_commands/command_definition.rb      | 57 +++++++++++++
 lib/gitlab/slash_commands/dsl.rb              | 82 +++++--------------
 lib/gitlab/slash_commands/extractor.rb        | 30 +++++--
 .../gitlab/slash_commands/extractor_spec.rb   | 30 +++----
 11 files changed, 191 insertions(+), 165 deletions(-)
 create mode 100644 lib/gitlab/slash_commands/command_definition.rb

diff --git a/app/controllers/projects_controller.rb b/app/controllers/projects_controller.rb
index 9c387fd3daa..93338dba51e 100644
--- a/app/controllers/projects_controller.rb
+++ b/app/controllers/projects_controller.rb
@@ -134,8 +134,22 @@ class ProjectsController < Projects::ApplicationController
   end
 
   def autocomplete_sources
-    autocomplete = ::Projects::AutocompleteService.new(@project, current_user, params)
-    participants = ::Projects::ParticipantsService.new(@project, current_user, params).execute
+    noteable =
+      case params[:type]
+      when 'Issue'
+        IssuesFinder.new(current_user, project_id: project.id, state: 'all').
+          execute.find_by(iid: params[:type_id])
+      when 'MergeRequest'
+        MergeRequestsFinder.new(current_user, project_id: project.id, state: 'all').
+          execute.find_by(iid: params[:type_id])
+      when 'Commit'
+        project.commit(params[:type_id])
+      else
+        nil
+      end
+
+    autocomplete = ::Projects::AutocompleteService.new(@project, current_user)
+    participants = ::Projects::ParticipantsService.new(@project, current_user).execute(noteable)
 
     @suggestions = {
       emojis: Gitlab::AwardEmoji.urls,
@@ -144,7 +158,7 @@ class ProjectsController < Projects::ApplicationController
       mergerequests: autocomplete.merge_requests,
       labels: autocomplete.labels,
       members: participants,
-      commands: autocomplete.commands
+      commands: autocomplete.commands(noteable, params[:type])
     }
 
     respond_to do |format|
diff --git a/app/services/issuable_base_service.rb b/app/services/issuable_base_service.rb
index 1a01b333366..aa08eef081c 100644
--- a/app/services/issuable_base_service.rb
+++ b/app/services/issuable_base_service.rb
@@ -94,10 +94,13 @@ class IssuableBaseService < BaseService
   end
 
   def merge_slash_commands_into_params!(issuable)
-    commands = SlashCommands::InterpretService.new(project, current_user).
+    description, command_params =
+      SlashCommands::InterpretService.new(project, current_user).
       execute(params[:description], issuable)
 
-    params.merge!(commands)
+    params[:description] = description
+
+    params.merge!(command_params)
   end
 
   def create_issuable(issuable, attributes)
diff --git a/app/services/notes/create_service.rb b/app/services/notes/create_service.rb
index 1b2d63034b8..f7cf4a8edc0 100644
--- a/app/services/notes/create_service.rb
+++ b/app/services/notes/create_service.rb
@@ -15,7 +15,9 @@ module Notes
       # **before** we save the note because if the note consists of commands
       # only, there is no need be create a note!
       slash_commands_service = SlashCommandsService.new(project, current_user)
-      commands = slash_commands_service.extract_commands(note)
+      content, command_params = slash_commands_service.extract_commands(note)
+
+      note.note = content
 
       if note.save
         # Finish the harder work in the background
@@ -25,7 +27,7 @@ module Notes
 
       # We must add the error after we call #save because errors are reset
       # when #save is called
-      if slash_commands_service.execute(commands, note) && note.note.blank?
+      if slash_commands_service.execute(command_params, note) && note.note.blank?
         note.errors.add(:commands_only, 'Your commands are being executed.')
       end
 
diff --git a/app/services/notes/slash_commands_service.rb b/app/services/notes/slash_commands_service.rb
index ebced9577d8..f2c43775b72 100644
--- a/app/services/notes/slash_commands_service.rb
+++ b/app/services/notes/slash_commands_service.rb
@@ -1,6 +1,5 @@
 module Notes
   class SlashCommandsService < BaseService
-
     UPDATE_SERVICES = {
       'Issue' => Issues::UpdateService,
       'MergeRequest' => MergeRequests::UpdateService
@@ -15,11 +14,11 @@ module Notes
         execute(note.note, note.noteable)
     end
 
-    def execute(commands, note)
-      if commands.any?
-        @noteable_update_service.new(project, current_user, commands).
-          execute(note.noteable)
-      end
+    def execute(command_params, note)
+      return if command_params.empty?
+
+      @noteable_update_service.new(project, current_user, command_params).
+        execute(note.noteable)
     end
   end
 end
diff --git a/app/services/projects/autocomplete_service.rb b/app/services/projects/autocomplete_service.rb
index 477c999eff4..cb85ee6694d 100644
--- a/app/services/projects/autocomplete_service.rb
+++ b/app/services/projects/autocomplete_service.rb
@@ -1,7 +1,7 @@
 module Projects
   class AutocompleteService < BaseService
     def issues
-      @project.issues.visible_to_user(current_user).opened.select([:iid, :title])
+      IssuesFinder.new(current_user, project_id: project.id, state: 'opened').execute.select([:iid, :title])
     end
 
     def milestones
@@ -9,42 +9,34 @@ module Projects
     end
 
     def merge_requests
-      @project.merge_requests.opened.select([:iid, :title])
+      MergeRequestsFinder.new(current_user, project_id: project.id, state: 'opened').execute.select([:iid, :title])
     end
 
     def labels
       @project.labels.select([:title, :color])
     end
 
-    def commands
-      # We don't return commands when editing an issue or merge request
-      # This should be improved by not enabling autocomplete at the JS-level
-      # following this suggestion: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5021#note_13837384
-      return [] if !target || %w[edit update].include?(params[:action_name])
-
-      SlashCommands::InterpretService.command_definitions(
-        project: project,
-        noteable: target,
-        current_user: current_user
-      )
-    end
-
-    private
-
-    def target
-      @target ||= begin
-        noteable_id = params[:type_id]
-        case params[:type]
+    def commands(noteable, type)
+      noteable ||=
+        case type
         when 'Issue'
-          IssuesFinder.new(current_user, project_id: project.id, state: 'all').
-            execute.find_or_initialize_by(iid: noteable_id)
+          @project.issues.build
         when 'MergeRequest'
-          MergeRequestsFinder.new(current_user, project_id: project.id, state: 'all').
-            execute.find_or_initialize_by(iid: noteable_id)
-        else
-          nil
+          @project.merge_requests.build
         end
-      end
+
+      return [] unless noteable && noteable.is_a?(Issuable)
+
+      opts = {
+        project: project,
+        noteable: noteable,
+        current_user: current_user
+      }
+      SlashCommands::InterpretService.command_definitions.map do |definition|
+        next unless definition.available?(opts)
+
+        definition.to_h(opts)
+      end.compact
     end
   end
 end
diff --git a/app/services/projects/participants_service.rb b/app/services/projects/participants_service.rb
index 1c8f2913e8b..d38328403c1 100644
--- a/app/services/projects/participants_service.rb
+++ b/app/services/projects/participants_service.rb
@@ -1,45 +1,28 @@
 module Projects
   class ParticipantsService < BaseService
-    attr_reader :noteable_type, :noteable_id
-
-    def execute
-      @noteable_type = params[:type]
-      @noteable_id = params[:type_id]
+    attr_reader :noteable
+    
+    def execute(noteable)
+      @noteable = noteable
 
       project_members = sorted(project.team.members)
-      participants = target_owner + participants_in_target + all_members + groups + project_members
+      participants = noteable_owner + participants_in_noteable + all_members + groups + project_members
       participants.uniq
     end
 
-    def target
-      @target ||=
-        case noteable_type
-        when 'Issue'
-          IssuesFinder.new(current_user, project_id: project.id, state: 'all').
-            execute.find_by(iid: noteable_id)
-        when 'MergeRequest'
-          MergeRequestsFinder.new(current_user, project_id: project.id, state: 'all').
-            execute.find_by(iid: noteable_id)
-        when 'Commit'
-          project.commit(noteable_id)
-        else
-          nil
-        end
-    end
-
-    def target_owner
-      return [] unless target && target.author.present?
+    def noteable_owner
+      return [] unless noteable && noteable.author.present?
 
       [{
-        name: target.author.name,
-        username: target.author.username
+        name: noteable.author.name,
+        username: noteable.author.username
       }]
     end
 
-    def participants_in_target
-      return [] unless target
+    def participants_in_noteable
+      return [] unless noteable
 
-      users = target.participants(current_user)
+      users = noteable.participants(current_user)
       sorted(users)
     end
 
diff --git a/app/services/slash_commands/interpret_service.rb b/app/services/slash_commands/interpret_service.rb
index 112bebe423a..a2b92d70f9f 100644
--- a/app/services/slash_commands/interpret_service.rb
+++ b/app/services/slash_commands/interpret_service.rb
@@ -10,20 +10,28 @@ module SlashCommands
       @noteable = noteable
       @updates = {}
 
-      commands = extractor(noteable: noteable).extract_commands!(content)
-      commands.each do |command, *args|
-        execute_command(command, *args)
+      opts = {
+        noteable:     noteable,
+        current_user: current_user,
+        project:      project
+      }
+
+      content, commands = extractor.extract_commands(content, opts)
+
+      commands.each do |name, *args|
+        definition = self.class.command_definitions_by_name[name.to_sym]
+        next unless definition
+
+        definition.execute(self, opts, *args)
       end
 
-      @updates
+      [content, @updates]
     end
 
     private
 
-    def extractor(opts = {})
-      opts.merge!(current_user: current_user, project: project)
-
-      Gitlab::SlashCommands::Extractor.new(self.class.command_names(opts))
+    def extractor
+      Gitlab::SlashCommands::Extractor.new(self.class.command_definitions)
     end
 
     desc do
diff --git a/lib/gitlab/slash_commands/command_definition.rb b/lib/gitlab/slash_commands/command_definition.rb
new file mode 100644
index 00000000000..5dec6c91869
--- /dev/null
+++ b/lib/gitlab/slash_commands/command_definition.rb
@@ -0,0 +1,57 @@
+module Gitlab
+  module SlashCommands
+    class CommandDefinition
+      attr_accessor :name, :aliases, :description, :params, :condition_block, :action_block
+
+      def valid?
+        name.present?
+      end
+
+      def all_names
+        [name, *aliases]
+      end
+
+      def noop?
+        action_block.nil?
+      end
+
+      def available?(opts)
+        return true unless condition_block
+
+        context = OpenStruct.new(opts)
+        context.instance_exec(&condition_block)
+      end
+
+      def to_description(opts)
+        return description unless description.respond_to?(:call)
+
+        context = OpenStruct.new(opts)
+        context.instance_exec(&description) rescue ''
+      end
+
+      def execute(context, opts, *args)
+        return if noop? || !available?(opts)
+
+        block_arity = action_block.arity
+        return unless block_arity == -1 || block_arity == args.size
+
+        context.instance_exec(*args, &action_block)
+      end
+
+      def to_h(opts)
+        desc = description
+        if desc.respond_to?(:call)
+          context = OpenStruct.new(opts)
+          desc = context.instance_exec(&desc) rescue ''
+        end
+
+        {
+          name: name,
+          aliases: aliases,
+          description: desc,
+          params: params
+        }
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/slash_commands/dsl.rb b/lib/gitlab/slash_commands/dsl.rb
index ce659aff1da..58ba7027f84 100644
--- a/lib/gitlab/slash_commands/dsl.rb
+++ b/lib/gitlab/slash_commands/dsl.rb
@@ -4,64 +4,16 @@ module Gitlab
       extend ActiveSupport::Concern
 
       included do
-        cattr_accessor :definitions
-      end
-
-      def execute_command(name, *args)
-        name = name.to_sym
-        cmd_def = self.class.definitions.find do |cmd_def|
-          self.class.command_name_and_aliases(cmd_def).include?(name)
+        cattr_accessor :command_definitions, instance_accessor: false do
+          []
         end
-        return unless cmd_def && cmd_def[:action_block]
-        return if self.class.command_unavailable?(cmd_def, self)
 
-        block_arity = cmd_def[:action_block].arity
-        if block_arity == -1 || block_arity == args.size
-          instance_exec(*args, &cmd_def[:action_block])
+        cattr_accessor :command_definitions_by_name, instance_accessor: false do
+          {}
         end
       end
 
       class_methods do
-        # This method is used to generate the autocompletion menu.
-        # It returns no-op slash commands (such as `/cc`).
-        def command_definitions(opts = {})
-          self.definitions.map do |cmd_def|
-            context = OpenStruct.new(opts)
-            next if command_unavailable?(cmd_def, context)
-
-            cmd_def = cmd_def.dup
-
-            if cmd_def[:description].respond_to?(:call)
-              cmd_def[:description] = context.instance_exec(&cmd_def[:description]) rescue ''
-            end
-
-            cmd_def
-          end.compact
-        end
-
-        # This method is used to generate a list of valid commands in the current
-        # context of `opts`.
-        # It excludes no-op slash commands (such as `/cc`).
-        # This list can then be given to `Gitlab::SlashCommands::Extractor`.
-        def command_names(opts = {})
-          self.definitions.flat_map do |cmd_def|
-            next if cmd_def[:opts].fetch(:noop, false)
-
-            context = OpenStruct.new(opts)
-            next if command_unavailable?(cmd_def, context)
-
-            command_name_and_aliases(cmd_def)
-          end.compact
-        end
-
-        def command_unavailable?(cmd_def, context)
-          cmd_def[:condition_block] && !context.instance_exec(&cmd_def[:condition_block])
-        end
-
-        def command_name_and_aliases(cmd_def)
-          [cmd_def[:name], *cmd_def[:aliases]]
-        end
-
         # Allows to give a description to the next slash command.
         # This description is shown in the autocomplete menu.
         # It accepts a block that will be evaluated with the context given to
@@ -119,19 +71,23 @@ module Gitlab
         #     # Awesome code block
         #   end
         def command(*command_names, &block)
-          opts = command_names.extract_options!
           name, *aliases = command_names
 
-          self.definitions ||= []
-          self.definitions << {
-            name: name,
-            aliases: aliases,
-            description: @description || '',
-            params: @params || [],
-            condition_block: @condition_block,
-            action_block: block,
-            opts: opts
-          }
+          definition = CommandDefinition.new
+          definition.name            =  name
+          definition.aliases         =  aliases
+          definition.description     =  @description || ''
+          definition.params          =  @params || []
+          definition.condition_block =  @condition_block
+          definition.action_block    =  block
+
+          return unless definition.valid?
+
+          self.command_definitions << definition
+
+          definition.all_names.each do |name|
+            self.command_definitions_by_name[name] = definition
+          end
 
           @description = nil
           @params = nil
diff --git a/lib/gitlab/slash_commands/extractor.rb b/lib/gitlab/slash_commands/extractor.rb
index ce0a2eba535..a6838cb5e7c 100644
--- a/lib/gitlab/slash_commands/extractor.rb
+++ b/lib/gitlab/slash_commands/extractor.rb
@@ -7,10 +7,10 @@ module Gitlab
     # extractor = Gitlab::SlashCommands::Extractor.new([:open, :assign, :labels])
     # ```
     class Extractor
-      attr_reader :command_names
+      attr_reader :command_definitions
 
-      def initialize(command_names)
-        @command_names = command_names
+      def initialize(command_definitions)
+        @command_definitions = command_definitions
       end
 
       # Extracts commands from content and return an array of commands.
@@ -26,16 +26,18 @@ module Gitlab
       # ```
       # extractor = Gitlab::SlashCommands::Extractor.new([:open, :assign, :labels])
       # msg = %(hello\n/labels ~foo ~"bar baz"\nworld)
-      # commands = extractor.extract_commands! #=> [['labels', '~foo ~"bar baz"']]
+      # commands = extractor.extract_commands(msg) #=> [['labels', '~foo ~"bar baz"']]
       # msg #=> "hello\nworld"
       # ```
-      def extract_commands!(content)
+      def extract_commands(content, opts)
         return [] unless content
 
+        content = content.dup
+
         commands = []
 
         content.delete!("\r")
-        content.gsub!(commands_regex) do
+        content.gsub!(commands_regex(opts)) do
           if $~[:cmd]
             commands << [$~[:cmd], $~[:args]].reject(&:blank?)
             ''
@@ -44,11 +46,19 @@ module Gitlab
           end
         end
 
-        commands
+        [content.strip, commands]
       end
 
       private
 
+      def command_names(opts)
+        command_definitions.flat_map do |command|
+          next if command.noop?
+
+          command.all_names
+        end.compact
+      end
+
       # Builds a regular expression to match known commands.
       # First match group captures the command name and
       # second match group captures its arguments.
@@ -56,7 +66,9 @@ module Gitlab
       # It looks something like:
       #
       #   /^\/(?<cmd>close|reopen|...)(?:( |$))(?<args>[^\/\n]*)(?:\n|$)/
-      def commands_regex
+      def commands_regex(opts)
+        names = command_names(opts).map(&:to_s)
+
         @commands_regex ||= %r{
             (?<code>
               # Code blocks:
@@ -95,7 +107,7 @@ module Gitlab
               # Command not in a blockquote, blockcode, or HTML tag:
               # /close
 
-              ^\/(?<cmd>#{command_names.join('|')})(?:(\ |$))(?<args>[^\/\n]*)(?:\n|$)
+              ^\/(?<cmd>#{Regexp.union(names)})(?:$|\ (?<args>[^\/\n]*)$)
             )
         }mx
       end
diff --git a/spec/lib/gitlab/slash_commands/extractor_spec.rb b/spec/lib/gitlab/slash_commands/extractor_spec.rb
index ac7296bdba1..8a6801205fa 100644
--- a/spec/lib/gitlab/slash_commands/extractor_spec.rb
+++ b/spec/lib/gitlab/slash_commands/extractor_spec.rb
@@ -5,7 +5,7 @@ describe Gitlab::SlashCommands::Extractor do
 
   shared_examples 'command with no argument' do
     it 'extracts command' do
-      commands = extractor.extract_commands!(original_msg)
+      commands = extractor.extract_commands(original_msg)
 
       expect(commands).to eq [['open']]
       expect(original_msg).to eq final_msg
@@ -14,7 +14,7 @@ describe Gitlab::SlashCommands::Extractor do
 
   shared_examples 'command with a single argument' do
     it 'extracts command' do
-      commands = extractor.extract_commands!(original_msg)
+      commands = extractor.extract_commands(original_msg)
 
       expect(commands).to eq [['assign', '@joe']]
       expect(original_msg).to eq final_msg
@@ -23,14 +23,14 @@ describe Gitlab::SlashCommands::Extractor do
 
   shared_examples 'command with multiple arguments' do
     it 'extracts command' do
-      commands = extractor.extract_commands!(original_msg)
+      commands = extractor.extract_commands(original_msg)
 
       expect(commands).to eq [['labels', '~foo ~"bar baz" label']]
       expect(original_msg).to eq final_msg
     end
   end
 
-  describe '#extract_commands!' do
+  describe '#extract_commands' do
     describe 'command with no argument' do
       context 'at the start of content' do
         it_behaves_like 'command with no argument' do
@@ -49,7 +49,7 @@ describe Gitlab::SlashCommands::Extractor do
       context 'in the middle of a line' do
         it 'does not extract command' do
           msg = "hello\nworld /open"
-          commands = extractor.extract_commands!(msg)
+          commands = extractor.extract_commands(msg)
 
           expect(commands).to be_empty
           expect(msg).to eq "hello\nworld /open"
@@ -82,7 +82,7 @@ describe Gitlab::SlashCommands::Extractor do
       context 'in the middle of a line' do
         it 'does not extract command' do
           msg = "hello\nworld /assign @joe"
-          commands = extractor.extract_commands!(msg)
+          commands = extractor.extract_commands(msg)
 
           expect(commands).to be_empty
           expect(msg).to eq "hello\nworld /assign @joe"
@@ -99,7 +99,7 @@ describe Gitlab::SlashCommands::Extractor do
       context 'when argument is not separated with a space' do
         it 'does not extract command' do
           msg = "hello\n/assign@joe\nworld"
-          commands = extractor.extract_commands!(msg)
+          commands = extractor.extract_commands(msg)
 
           expect(commands).to be_empty
           expect(msg).to eq "hello\n/assign@joe\nworld"
@@ -125,7 +125,7 @@ describe Gitlab::SlashCommands::Extractor do
       context 'in the middle of a line' do
         it 'does not extract command' do
           msg = %(hello\nworld /labels ~foo ~"bar baz" label)
-          commands = extractor.extract_commands!(msg)
+          commands = extractor.extract_commands(msg)
 
           expect(commands).to be_empty
           expect(msg).to eq %(hello\nworld /labels ~foo ~"bar baz" label)
@@ -142,7 +142,7 @@ describe Gitlab::SlashCommands::Extractor do
       context 'when argument is not separated with a space' do
         it 'does not extract command' do
           msg = %(hello\n/labels~foo ~"bar baz" label\nworld)
-          commands = extractor.extract_commands!(msg)
+          commands = extractor.extract_commands(msg)
 
           expect(commands).to be_empty
           expect(msg).to eq %(hello\n/labels~foo ~"bar baz" label\nworld)
@@ -152,7 +152,7 @@ describe Gitlab::SlashCommands::Extractor do
 
     it 'extracts command with multiple arguments and various prefixes' do
       msg = %(hello\n/power @user.name %9.10 ~"bar baz.2"\nworld)
-      commands = extractor.extract_commands!(msg)
+      commands = extractor.extract_commands(msg)
 
       expect(commands).to eq [['power', '@user.name %9.10 ~"bar baz.2"']]
       expect(msg).to eq "hello\nworld"
@@ -160,7 +160,7 @@ describe Gitlab::SlashCommands::Extractor do
 
     it 'extracts multiple commands' do
       msg = %(hello\n/power @user.name %9.10 ~"bar baz.2" label\nworld\n/open)
-      commands = extractor.extract_commands!(msg)
+      commands = extractor.extract_commands(msg)
 
       expect(commands).to eq [['power', '@user.name %9.10 ~"bar baz.2" label'], ['open']]
       expect(msg).to eq "hello\nworld\n"
@@ -168,7 +168,7 @@ describe Gitlab::SlashCommands::Extractor do
 
     it 'does not alter original content if no command is found' do
       msg = 'Fixes #123'
-      commands = extractor.extract_commands!(msg)
+      commands = extractor.extract_commands(msg)
 
       expect(commands).to be_empty
       expect(msg).to eq 'Fixes #123'
@@ -177,7 +177,7 @@ describe Gitlab::SlashCommands::Extractor do
     it 'does not extract commands inside a blockcode' do
       msg = "Hello\r\n```\r\nThis is some text\r\n/close\r\n/assign @user\r\n```\r\n\r\nWorld"
       expected = msg.delete("\r")
-      commands = extractor.extract_commands!(msg)
+      commands = extractor.extract_commands(msg)
 
       expect(commands).to be_empty
       expect(msg).to eq expected
@@ -186,7 +186,7 @@ describe Gitlab::SlashCommands::Extractor do
     it 'does not extract commands inside a blockquote' do
       msg = "Hello\r\n>>>\r\nThis is some text\r\n/close\r\n/assign @user\r\n>>>\r\n\r\nWorld"
       expected = msg.delete("\r")
-      commands = extractor.extract_commands!(msg)
+      commands = extractor.extract_commands(msg)
 
       expect(commands).to be_empty
       expect(msg).to eq expected
@@ -195,7 +195,7 @@ describe Gitlab::SlashCommands::Extractor do
     it 'does not extract commands inside a HTML tag' do
       msg = "Hello\r\n<div>\r\nThis is some text\r\n/close\r\n/assign @user\r\n</div>\r\n\r\nWorld"
       expected = msg.delete("\r")
-      commands = extractor.extract_commands!(msg)
+      commands = extractor.extract_commands(msg)
 
       expect(commands).to be_empty
       expect(msg).to eq expected

From ccd44546589297bcb36a92f8cbb1a6d13bcf1abf Mon Sep 17 00:00:00 2001
From: Douwe Maan <douwe@selenight.nl>
Date: Fri, 12 Aug 2016 20:17:57 -0500
Subject: [PATCH 13/25] Fix autocomplete on commit and issue/MR edit pages

---
 app/controllers/projects/commit_controller.rb         |  2 +-
 app/controllers/projects/issues_controller.rb         | 11 ++++++-----
 app/controllers/projects/merge_requests_controller.rb |  2 +-
 3 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/app/controllers/projects/commit_controller.rb b/app/controllers/projects/commit_controller.rb
index f44e9bb3fd7..02fb3f56890 100644
--- a/app/controllers/projects/commit_controller.rb
+++ b/app/controllers/projects/commit_controller.rb
@@ -93,7 +93,7 @@ class Projects::CommitController < Projects::ApplicationController
   end
 
   def commit
-    @commit ||= @project.commit(params[:id])
+    @noteable = @commit ||= @project.commit(params[:id])
   end
 
   def pipelines
diff --git a/app/controllers/projects/issues_controller.rb b/app/controllers/projects/issues_controller.rb
index 660e0eba06f..c8eda6b27f4 100644
--- a/app/controllers/projects/issues_controller.rb
+++ b/app/controllers/projects/issues_controller.rb
@@ -176,11 +176,12 @@ class Projects::IssuesController < Projects::ApplicationController
   protected
 
   def issue
-    @issue ||= begin
-                 @project.issues.find_by!(iid: params[:id])
-               rescue ActiveRecord::RecordNotFound
-                 redirect_old
-               end
+    @noteable = @issue ||=
+      begin
+        @project.issues.find_by!(iid: params[:id])
+      rescue ActiveRecord::RecordNotFound
+        redirect_old
+      end
   end
   alias_method :subscribable_resource, :issue
   alias_method :issuable, :issue
diff --git a/app/controllers/projects/merge_requests_controller.rb b/app/controllers/projects/merge_requests_controller.rb
index 139680d2df9..8e82a8c0360 100644
--- a/app/controllers/projects/merge_requests_controller.rb
+++ b/app/controllers/projects/merge_requests_controller.rb
@@ -324,7 +324,7 @@ class Projects::MergeRequestsController < Projects::ApplicationController
   end
 
   def merge_request
-    @merge_request ||= @project.merge_requests.find_by!(iid: params[:id])
+    @issuable = @merge_request ||= @project.merge_requests.find_by!(iid: params[:id])
   end
   alias_method :subscribable_resource, :merge_request
   alias_method :issuable, :merge_request

From f48e898619a104aa379af0a037fb96d09ee8675f Mon Sep 17 00:00:00 2001
From: Douwe Maan <douwe@selenight.nl>
Date: Fri, 12 Aug 2016 20:19:16 -0500
Subject: [PATCH 14/25] Disable slash commands on edit forms

---
 app/assets/javascripts/gfm_auto_complete.js.es6 | 4 ++--
 app/views/layouts/_init_auto_complete.html.haml | 4 ++--
 app/views/projects/_zen.html.haml               | 3 ++-
 app/views/projects/notes/_form.html.haml        | 6 +++++-
 app/views/shared/issuable/_form.html.haml       | 3 ++-
 5 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/app/assets/javascripts/gfm_auto_complete.js.es6 b/app/assets/javascripts/gfm_auto_complete.js.es6
index 2e1cbb362a3..3d6f704c9b0 100644
--- a/app/assets/javascripts/gfm_auto_complete.js.es6
+++ b/app/assets/javascripts/gfm_auto_complete.js.es6
@@ -249,8 +249,8 @@
           }
         }
       });
-      // We don't instantiate the slash commands autocomplete for note edit forms
-      $("form:not(.edit-note) .js-gfm-input").atwho({
+      // We don't instantiate the slash commands autocomplete for note and issue/MR edit forms
+      this.input.filter('[data-supports-slash-commands="true"]').atwho({
         at: '/',
         alias: 'commands',
         displayTpl: function(value) {
diff --git a/app/views/layouts/_init_auto_complete.html.haml b/app/views/layouts/_init_auto_complete.html.haml
index a51347fde83..67ff4b272b9 100644
--- a/app/views/layouts/_init_auto_complete.html.haml
+++ b/app/views/layouts/_init_auto_complete.html.haml
@@ -1,7 +1,7 @@
 - project = @target_project || @project
-- noteable_class = @noteable.class if @noteable.present?
+- noteable_type = @noteable.class if @noteable.present?
 
 :javascript
-  GitLab.GfmAutoComplete.dataSource = "#{autocomplete_sources_namespace_project_path(project.namespace, project, type: noteable_class, type_id: params[:id], action_name: action_name)}"
+  GitLab.GfmAutoComplete.dataSource = "#{autocomplete_sources_namespace_project_path(project.namespace, project, type: noteable_type, type_id: params[:id])}"
   GitLab.GfmAutoComplete.cachedData = undefined;
   GitLab.GfmAutoComplete.setup();
diff --git a/app/views/projects/_zen.html.haml b/app/views/projects/_zen.html.haml
index 413477a2d3a..3978fa60d66 100644
--- a/app/views/projects/_zen.html.haml
+++ b/app/views/projects/_zen.html.haml
@@ -1,7 +1,8 @@
+- supports_slash_commands = local_assigns.fetch(:supports_slash_commands, false)
 .zen-backdrop
   - classes << ' js-gfm-input js-autosize markdown-area'
   - if defined?(f) && f
-    = f.text_area attr, class: classes, placeholder: placeholder
+    = f.text_area attr, class: classes, placeholder: placeholder, data: { supports_slash_commands: supports_slash_commands }
   - else
     = text_area_tag attr, nil, class: classes, placeholder: placeholder
   %a.zen-control.zen-control-leave.js-zen-leave{ href: "#" }
diff --git a/app/views/projects/notes/_form.html.haml b/app/views/projects/notes/_form.html.haml
index 7c61ba750fe..b2a31607824 100644
--- a/app/views/projects/notes/_form.html.haml
+++ b/app/views/projects/notes/_form.html.haml
@@ -10,7 +10,11 @@
   = f.hidden_field :position
 
   = render layout: 'projects/md_preview', locals: { preview_class: "md-preview", referenced_users: true } do
-    = render 'projects/zen', f: f, attr: :note, classes: 'note-textarea js-note-text', placeholder: "Write a comment or drag your files here..."
+    = render 'projects/zen', f: f,
+      attr: :note,
+      classes: 'note-textarea js-note-text',
+      placeholder: "Write a comment or drag your files here...",
+      supports_slash_commands: true
     = render 'projects/notes/hints'
     .error-alert
 
diff --git a/app/views/shared/issuable/_form.html.haml b/app/views/shared/issuable/_form.html.haml
index c30bdb0ae91..7e4062c8d4d 100644
--- a/app/views/shared/issuable/_form.html.haml
+++ b/app/views/shared/issuable/_form.html.haml
@@ -30,7 +30,8 @@
     = render layout: 'projects/md_preview', locals: { preview_class: "md-preview", referenced_users: true } do
       = render 'projects/zen', f: f, attr: :description,
                                classes: 'note-textarea',
-                               placeholder: "Write a comment or drag your files here..."
+                               placeholder: "Write a comment or drag your files here...",
+                               supports_slash_commands: !issuable.persisted?
       = render 'projects/notes/hints'
       .clearfix
       .error-alert

From 489e8992cfb4076fb4bf7f1c68bd945d30a26bbf Mon Sep 17 00:00:00 2001
From: Douwe Maan <douwe@selenight.nl>
Date: Fri, 12 Aug 2016 20:19:52 -0500
Subject: [PATCH 15/25] Link to slash commands documentation from form hints

---
 app/views/projects/notes/_form.html.haml  |  2 +-
 app/views/projects/notes/_hints.html.haml | 11 +++++++++--
 app/views/shared/issuable/_form.html.haml |  2 +-
 3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/app/views/projects/notes/_form.html.haml b/app/views/projects/notes/_form.html.haml
index b2a31607824..759c72b2477 100644
--- a/app/views/projects/notes/_form.html.haml
+++ b/app/views/projects/notes/_form.html.haml
@@ -15,7 +15,7 @@
       classes: 'note-textarea js-note-text',
       placeholder: "Write a comment or drag your files here...",
       supports_slash_commands: true
-    = render 'projects/notes/hints'
+    = render 'projects/notes/hints', supports_slash_commands: true
     .error-alert
 
   .note-form-actions.clearfix
diff --git a/app/views/projects/notes/_hints.html.haml b/app/views/projects/notes/_hints.html.haml
index 25466e7562e..cf6e14648cc 100644
--- a/app/views/projects/notes/_hints.html.haml
+++ b/app/views/projects/notes/_hints.html.haml
@@ -1,8 +1,15 @@
+- supports_slash_commands = local_assigns.fetch(:supports_slash_commands, false)
 .comment-toolbar.clearfix
   .toolbar-text
     Styling with
     = link_to 'Markdown', help_page_path('markdown/markdown'), target: '_blank', tabindex: -1
-    is supported
+    - if supports_slash_commands
+      and
+      = link_to 'slash commands', help_page_path('workflow/slash_commands'), target: '_blank', tabindex: -1
+      are
+    - else
+      is
+    supported
   %button.toolbar-button.markdown-selector{ type: 'button', tabindex: '-1' }
     = icon('file-image-o', class: 'toolbar-button-icon')
-    Attach a file
\ No newline at end of file
+    Attach a file
diff --git a/app/views/shared/issuable/_form.html.haml b/app/views/shared/issuable/_form.html.haml
index 7e4062c8d4d..25b29ccf70d 100644
--- a/app/views/shared/issuable/_form.html.haml
+++ b/app/views/shared/issuable/_form.html.haml
@@ -32,7 +32,7 @@
                                classes: 'note-textarea',
                                placeholder: "Write a comment or drag your files here...",
                                supports_slash_commands: !issuable.persisted?
-      = render 'projects/notes/hints'
+      = render 'projects/notes/hints', supports_slash_commands: !issuable.persisted?
       .clearfix
       .error-alert
 

From 0afb96015034307f49d6b28da2c9a4143352ac97 Mon Sep 17 00:00:00 2001
From: Douwe Maan <douwe@selenight.nl>
Date: Fri, 12 Aug 2016 20:20:07 -0500
Subject: [PATCH 16/25] Autocomplete based on names and aliases

---
 app/assets/javascripts/gfm_auto_complete.js.es6 | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/app/assets/javascripts/gfm_auto_complete.js.es6 b/app/assets/javascripts/gfm_auto_complete.js.es6
index 3d6f704c9b0..3dca06d36b1 100644
--- a/app/assets/javascripts/gfm_auto_complete.js.es6
+++ b/app/assets/javascripts/gfm_auto_complete.js.es6
@@ -253,6 +253,7 @@
       this.input.filter('[data-supports-slash-commands="true"]').atwho({
         at: '/',
         alias: 'commands',
+        searchKey: 'search',
         displayTpl: function(value) {
           var tpl = '<li>/${name}';
           if (value.aliases.length > 0) {
@@ -283,6 +284,21 @@
           sorter: this.DefaultOptions.sorter,
           filter: this.DefaultOptions.filter,
           beforeInsert: this.DefaultOptions.beforeInsert,
+          beforeSave: function(commands) {
+            return $.map(commands, function(c) {
+              var search = c.name;
+              if (c.aliases.length > 0) {
+                search = search + " " + c.aliases.join(" ");
+              }
+              return {
+                name: c.name,
+                aliases: c.aliases,
+                params: c.params,
+                description: c.description,
+                search: search
+              };
+            });
+          },
           matcher: function(flag, subtext, should_startWithSpace, acceptSpaceBar) {
             var regexp = /(?:^|\n)\/([A-Za-z_]*)$/gi
             var match = regexp.exec(subtext);

From 463ae8f570f986d9f50ae42067715d6db0dc1541 Mon Sep 17 00:00:00 2001
From: Douwe Maan <douwe@selenight.nl>
Date: Fri, 12 Aug 2016 20:20:51 -0500
Subject: [PATCH 17/25] Force notes poll after commands have been executed

---
 app/assets/javascripts/notes.js               | 40 ++++++++++---------
 app/services/notes/create_service.rb          |  2 +-
 .../issues/user_uses_slash_commands_spec.rb   |  4 +-
 ...issuable_slash_commands_shared_examples.rb | 22 +++++-----
 4 files changed, 35 insertions(+), 33 deletions(-)

diff --git a/app/assets/javascripts/notes.js b/app/assets/javascripts/notes.js
index 99bc1a640a8..2484a07f363 100644
--- a/app/assets/javascripts/notes.js
+++ b/app/assets/javascripts/notes.js
@@ -201,7 +201,7 @@
     Increase @pollingInterval up to 120 seconds on every function call,
     if `shouldReset` has a truthy value, 'null' or 'undefined' the variable
     will reset to @basePollingInterval.
-    
+
     Note: this function is used to gradually increase the polling interval
     if there aren't new notes coming from the server
      */
@@ -223,7 +223,7 @@
 
     /*
     Render note in main comments area.
-    
+
     Note: for rendering inline notes use renderDiscussionNote
      */
 
@@ -236,6 +236,7 @@
         else {
           if (note.errors.commands_only) {
             new Flash(note.errors.commands_only, 'notice', this.parentTimeline);
+            this.refresh();
           }
         }
         return;
@@ -250,6 +251,7 @@
         $notesList.append(note.html).syntaxHighlight();
         gl.utils.localTimeAgo($notesList.find("#note_" + note.id + " .js-timeago"), false);
         this.initTaskList();
+        this.refresh();
         return this.updateNotesCount(1);
       }
     };
@@ -270,7 +272,7 @@
 
     /*
     Render note in discussion area.
-    
+
     Note: for rendering inline notes use renderDiscussionNote
      */
 
@@ -309,7 +311,7 @@
 
     /*
     Called in response the main target form has been successfully submitted.
-    
+
     Removes any errors.
     Resets text and preview.
     Resets buttons.
@@ -334,7 +336,7 @@
 
     /*
     Shows the main form and does some setup on it.
-    
+
     Sets some hidden fields in the form.
      */
 
@@ -354,7 +356,7 @@
 
     /*
     General note form setup.
-    
+
     deactivates the submit button when text is empty
     hides the preview button when text is empty
     setup GFM auto complete
@@ -371,7 +373,7 @@
 
     /*
     Called in response to the new note form being submitted
-    
+
     Adds new note to list.
      */
 
@@ -386,7 +388,7 @@
 
     /*
     Called in response to the new note form being submitted
-    
+
     Adds new note to list.
      */
 
@@ -398,7 +400,7 @@
 
     /*
     Called in response to the edit note form being submitted
-    
+
     Updates the current note field.
      */
 
@@ -415,7 +417,7 @@
 
     /*
     Called in response to clicking the edit note link
-    
+
     Replaces the note text with the note edit form
     Adds a data attribute to the form with the original content of the note for cancellations
      */
@@ -455,7 +457,7 @@
 
     /*
     Called in response to clicking the edit note link
-    
+
     Hides edit form and restores the original note text to the editor textarea.
      */
 
@@ -477,7 +479,7 @@
 
     /*
     Called in response to deleting a note of any kind.
-    
+
     Removes the actual note from view.
     Removes the whole discussion if the last note is being removed.
      */
@@ -503,7 +505,7 @@
 
     /*
     Called in response to clicking the delete attachment link
-    
+
     Removes the attachment wrapper view, including image tag if it exists
     Resets the note editing form
      */
@@ -520,7 +522,7 @@
 
     /*
     Called when clicking on the "reply" button for a diff line.
-    
+
     Shows the note form below the notes.
      */
 
@@ -536,9 +538,9 @@
 
     /*
     Shows the diff or discussion form and does some setup on it.
-    
+
     Sets some hidden fields in the form.
-    
+
     Note: dataHolder must have the "discussionId", "lineCode", "noteableType"
     and "noteableId" data attributes set.
      */
@@ -562,7 +564,7 @@
 
     /*
     Called when clicking on the "add a comment" button on the side of a diff line.
-    
+
     Inserts a temporary row for the form below the line.
     Sets up the form and shows it.
      */
@@ -610,7 +612,7 @@
 
     /*
     Called in response to "cancel" on a diff note form.
-    
+
     Shows the reply button again.
     Removes the form and if necessary it's temporary row.
      */
@@ -639,7 +641,7 @@
 
     /*
     Called after an attachment file has been selected.
-    
+
     Updates the file name for the selected attachment.
      */
 
diff --git a/app/services/notes/create_service.rb b/app/services/notes/create_service.rb
index f7cf4a8edc0..e9f37e04993 100644
--- a/app/services/notes/create_service.rb
+++ b/app/services/notes/create_service.rb
@@ -28,7 +28,7 @@ module Notes
       # We must add the error after we call #save because errors are reset
       # when #save is called
       if slash_commands_service.execute(command_params, note) && note.note.blank?
-        note.errors.add(:commands_only, 'Your commands are being executed.')
+        note.errors.add(:commands_only, 'Your commands have been executed!')
       end
 
       note
diff --git a/spec/features/issues/user_uses_slash_commands_spec.rb b/spec/features/issues/user_uses_slash_commands_spec.rb
index fe320070704..510f4254b54 100644
--- a/spec/features/issues/user_uses_slash_commands_spec.rb
+++ b/spec/features/issues/user_uses_slash_commands_spec.rb
@@ -27,7 +27,7 @@ feature 'Issues > User uses slash commands', feature: true, js: true do
         end
 
         expect(page).not_to have_content '/due_date 2016-08-28'
-        expect(page).to have_content 'Your commands are being executed.'
+        expect(page).to have_content 'Your commands have been executed!'
 
         issue.reload
 
@@ -47,7 +47,7 @@ feature 'Issues > User uses slash commands', feature: true, js: true do
         end
 
         expect(page).not_to have_content '/clear_due_date'
-        expect(page).to have_content 'Your commands are being executed.'
+        expect(page).to have_content 'Your commands have been executed!'
 
         issue.reload
 
diff --git a/spec/support/issuable_slash_commands_shared_examples.rb b/spec/support/issuable_slash_commands_shared_examples.rb
index e1255bd248d..ace14c19fd8 100644
--- a/spec/support/issuable_slash_commands_shared_examples.rb
+++ b/spec/support/issuable_slash_commands_shared_examples.rb
@@ -74,7 +74,7 @@ shared_examples 'issuable record that supports slash commands in its description
         expect(page).not_to have_content '/assign @bob'
         expect(page).not_to have_content '/label ~bug'
         expect(page).not_to have_content '/milestone %"ASAP"'
-        expect(page).to have_content 'Your commands are being executed.'
+        expect(page).to have_content 'Your commands have been executed!'
 
         issuable.reload
 
@@ -98,7 +98,7 @@ shared_examples 'issuable record that supports slash commands in its description
           end
 
           expect(page).not_to have_content '/close'
-          expect(page).to have_content 'Your commands are being executed.'
+          expect(page).to have_content 'Your commands have been executed!'
 
           expect(issuable.reload).to be_closed
         end
@@ -118,7 +118,7 @@ shared_examples 'issuable record that supports slash commands in its description
           end
 
           expect(page).not_to have_content '/close'
-          expect(page).not_to have_content 'Your commands are being executed.'
+          expect(page).not_to have_content 'Your commands have been executed!'
 
           expect(issuable).to be_open
         end
@@ -139,7 +139,7 @@ shared_examples 'issuable record that supports slash commands in its description
           end
 
           expect(page).not_to have_content '/reopen'
-          expect(page).to have_content 'Your commands are being executed.'
+          expect(page).to have_content 'Your commands have been executed!'
 
           expect(issuable.reload).to be_open
         end
@@ -159,7 +159,7 @@ shared_examples 'issuable record that supports slash commands in its description
           end
 
           expect(page).not_to have_content '/reopen'
-          expect(page).not_to have_content 'Your commands are being executed.'
+          expect(page).not_to have_content 'Your commands have been executed!'
 
           expect(issuable).to be_closed
         end
@@ -175,7 +175,7 @@ shared_examples 'issuable record that supports slash commands in its description
           end
 
           expect(page).not_to have_content '/title'
-          expect(page).to have_content 'Your commands are being executed.'
+          expect(page).to have_content 'Your commands have been executed!'
 
           expect(issuable.reload.title).to eq 'Awesome new title'
         end
@@ -195,7 +195,7 @@ shared_examples 'issuable record that supports slash commands in its description
           end
 
           expect(page).not_to have_content '/title'
-          expect(page).not_to have_content 'Your commands are being executed.'
+          expect(page).not_to have_content 'Your commands have been executed!'
 
           expect(issuable.reload.title).not_to eq 'Awesome new title'
         end
@@ -210,7 +210,7 @@ shared_examples 'issuable record that supports slash commands in its description
         end
 
         expect(page).not_to have_content '/todo'
-        expect(page).to have_content 'Your commands are being executed.'
+        expect(page).to have_content 'Your commands have been executed!'
 
         todos = TodosFinder.new(master).execute
         todo = todos.first
@@ -244,7 +244,7 @@ shared_examples 'issuable record that supports slash commands in its description
         end
 
         expect(page).not_to have_content '/done'
-        expect(page).to have_content 'Your commands are being executed.'
+        expect(page).to have_content 'Your commands have been executed!'
 
         expect(todo.reload).to be_done
       end
@@ -260,7 +260,7 @@ shared_examples 'issuable record that supports slash commands in its description
         end
 
         expect(page).not_to have_content '/subscribe'
-        expect(page).to have_content 'Your commands are being executed.'
+        expect(page).to have_content 'Your commands have been executed!'
 
         expect(issuable.subscribed?(master)).to be_truthy
       end
@@ -280,7 +280,7 @@ shared_examples 'issuable record that supports slash commands in its description
         end
 
         expect(page).not_to have_content '/unsubscribe'
-        expect(page).to have_content 'Your commands are being executed.'
+        expect(page).to have_content 'Your commands have been executed!'
 
         expect(issuable.subscribed?(master)).to be_falsy
       end

From d9715266e86e6a48616c24147e46c1219f4e0255 Mon Sep 17 00:00:00 2001
From: Douwe Maan <douwe@selenight.nl>
Date: Fri, 12 Aug 2016 20:23:33 -0500
Subject: [PATCH 18/25] Allow setting labels, milestones and assignee based on
 name

---
 app/services/slash_commands/interpret_service.rb | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/app/services/slash_commands/interpret_service.rb b/app/services/slash_commands/interpret_service.rb
index a2b92d70f9f..50e2a96eefb 100644
--- a/app/services/slash_commands/interpret_service.rb
+++ b/app/services/slash_commands/interpret_service.rb
@@ -74,6 +74,8 @@ module SlashCommands
     end
     command :assign, :reassign do |assignee_param|
       user = extract_references(assignee_param, :user).first
+      user ||= User.find_by(username: assignee_param)
+      user ||= User.find_by(name: assignee_param)
 
       @updates[:assignee_id] = user.id if user
     end
@@ -95,6 +97,7 @@ module SlashCommands
     end
     command :milestone do |milestone_param|
       milestone = extract_references(milestone_param, :milestone).first
+      milestone ||= project.milestones.find_by(title: milestone_param.strip)
 
       @updates[:milestone_id] = milestone.id if milestone
     end
@@ -204,12 +207,15 @@ module SlashCommands
     command :cc, noop: true
 
     def find_label_ids(labels_param)
-      extract_references(labels_param, :label).map(&:id)
+      label_ids_by_reference = extract_references(labels_param, :label).map(&:id)
+      labels_ids_by_name = @project.labels.where(name: labels_param.split).select(:id)
+
+      label_ids_by_reference | labels_ids_by_name
     end
 
-    def extract_references(cmd_arg, type)
+    def extract_references(arg, type)
       ext = Gitlab::ReferenceExtractor.new(project, current_user)
-      ext.analyze(cmd_arg, author: current_user)
+      ext.analyze(arg, author: current_user)
 
       ext.references(type)
     end

From b2b1b4a4226267dbc442d62e19949909d9e58235 Mon Sep 17 00:00:00 2001
From: Douwe Maan <douwe@selenight.nl>
Date: Fri, 12 Aug 2016 20:23:49 -0500
Subject: [PATCH 19/25] Prefer `/reopen` over `/open`, remove `/reassign`

---
 .../slash_commands/interpret_service.rb       | 42 +++++++++----------
 doc/workflow/slash_commands.md                |  6 +--
 2 files changed, 24 insertions(+), 24 deletions(-)

diff --git a/app/services/slash_commands/interpret_service.rb b/app/services/slash_commands/interpret_service.rb
index 50e2a96eefb..f7b9547bd2b 100644
--- a/app/services/slash_commands/interpret_service.rb
+++ b/app/services/slash_commands/interpret_service.rb
@@ -39,8 +39,8 @@ module SlashCommands
     end
     condition do
       noteable.persisted? &&
-      noteable.open? &&
-      current_user.can?(:"update_#{noteable.to_ability_name}", noteable)
+        noteable.open? &&
+        current_user.can?(:"update_#{noteable.to_ability_name}", noteable)
     end
     command :close do
       @updates[:state_event] = 'close'
@@ -51,9 +51,9 @@ module SlashCommands
     end
     condition do
       noteable.closed? &&
-      current_user.can?(:"update_#{noteable.to_ability_name}", noteable)
+        current_user.can?(:"update_#{noteable.to_ability_name}", noteable)
     end
-    command :open, :reopen do
+    command :reopen, :open do
       @updates[:state_event] = 'reopen'
     end
 
@@ -61,7 +61,7 @@ module SlashCommands
     params '<New title>'
     condition do
       noteable.persisted? &&
-      current_user.can?(:"update_#{noteable.to_ability_name}", noteable)
+        current_user.can?(:"update_#{noteable.to_ability_name}", noteable)
     end
     command :title do |title_param|
       @updates[:title] = title_param
@@ -72,7 +72,7 @@ module SlashCommands
     condition do
       current_user.can?(:"admin_#{noteable.to_ability_name}", project)
     end
-    command :assign, :reassign do |assignee_param|
+    command :assign do |assignee_param|
       user = extract_references(assignee_param, :user).first
       user ||= User.find_by(username: assignee_param)
       user ||= User.find_by(name: assignee_param)
@@ -83,7 +83,7 @@ module SlashCommands
     desc 'Remove assignee'
     condition do
       noteable.assignee_id? &&
-      current_user.can?(:"admin_#{noteable.to_ability_name}", project)
+        current_user.can?(:"admin_#{noteable.to_ability_name}", project)
     end
     command :unassign, :remove_assignee do
       @updates[:assignee_id] = nil
@@ -93,7 +93,7 @@ module SlashCommands
     params '%"milestone"'
     condition do
       current_user.can?(:"admin_#{noteable.to_ability_name}", project) &&
-      project.milestones.active.any?
+        project.milestones.active.any?
     end
     command :milestone do |milestone_param|
       milestone = extract_references(milestone_param, :milestone).first
@@ -105,7 +105,7 @@ module SlashCommands
     desc 'Remove milestone'
     condition do
       noteable.milestone_id? &&
-      current_user.can?(:"admin_#{noteable.to_ability_name}", project)
+        current_user.can?(:"admin_#{noteable.to_ability_name}", project)
     end
     command :clear_milestone, :remove_milestone do
       @updates[:milestone_id] = nil
@@ -115,7 +115,7 @@ module SlashCommands
     params '~label1 ~"label 2"'
     condition do
       current_user.can?(:"admin_#{noteable.to_ability_name}", project) &&
-      project.labels.any?
+        project.labels.any?
     end
     command :label, :labels do |labels_param|
       label_ids = find_label_ids(labels_param)
@@ -127,7 +127,7 @@ module SlashCommands
     params '~label1 ~"label 2"'
     condition do
       noteable.labels.any? &&
-      current_user.can?(:"admin_#{noteable.to_ability_name}", project)
+        current_user.can?(:"admin_#{noteable.to_ability_name}", project)
     end
     command :unlabel, :remove_label, :remove_labels do |labels_param|
       label_ids = find_label_ids(labels_param)
@@ -138,7 +138,7 @@ module SlashCommands
     desc 'Remove all labels'
     condition do
       noteable.labels.any? &&
-      current_user.can?(:"admin_#{noteable.to_ability_name}", project)
+        current_user.can?(:"admin_#{noteable.to_ability_name}", project)
     end
     command :clear_labels, :clear_label do
       @updates[:label_ids] = []
@@ -147,7 +147,7 @@ module SlashCommands
     desc 'Add a todo'
     condition do
       noteable.persisted? &&
-      !TodoService.new.todo_exist?(noteable, current_user)
+        !TodoService.new.todo_exist?(noteable, current_user)
     end
     command :todo do
       @updates[:todo_event] = 'add'
@@ -155,7 +155,7 @@ module SlashCommands
 
     desc 'Mark todo as done'
     condition do
-      TodoService.new.todo_exist?(noteable, current_user)
+        TodoService.new.todo_exist?(noteable, current_user)
     end
     command :done do
       @updates[:todo_event] = 'done'
@@ -164,7 +164,7 @@ module SlashCommands
     desc 'Subscribe'
     condition do
       noteable.persisted? &&
-      !noteable.subscribed?(current_user)
+        !noteable.subscribed?(current_user)
     end
     command :subscribe do
       @updates[:subscription_event] = 'subscribe'
@@ -173,17 +173,17 @@ module SlashCommands
     desc 'Unsubscribe'
     condition do
       noteable.persisted? &&
-      noteable.subscribed?(current_user)
+        noteable.subscribed?(current_user)
     end
     command :unsubscribe do
       @updates[:subscription_event] = 'unsubscribe'
     end
 
     desc 'Set due date'
-    params '<in 2 days | this Friday | December 31st>'
+    params '<in 2 days; this Friday; December 31st>'
     condition do
       noteable.respond_to?(:due_date) &&
-      current_user.can?(:"update_#{noteable.to_ability_name}", noteable)
+        current_user.can?(:"update_#{noteable.to_ability_name}", noteable)
     end
     command :due, :due_date do |due_date_param|
       due_date = Chronic.parse(due_date_param).try(:to_date)
@@ -194,8 +194,8 @@ module SlashCommands
     desc 'Remove due date'
     condition do
       noteable.respond_to?(:due_date) &&
-      noteable.due_date? &&
-      current_user.can?(:"update_#{noteable.to_ability_name}", noteable)
+        noteable.due_date? &&
+        current_user.can?(:"update_#{noteable.to_ability_name}", noteable)
     end
     command :clear_due_date do
       @updates[:due_date] = nil
@@ -204,7 +204,7 @@ module SlashCommands
     # This is a dummy command, so that it appears in the autocomplete commands
     desc 'CC'
     params '@user'
-    command :cc, noop: true
+    command :cc
 
     def find_label_ids(labels_param)
       label_ids_by_reference = extract_references(labels_param, :label).map(&:id)
diff --git a/doc/workflow/slash_commands.md b/doc/workflow/slash_commands.md
index 2bdc18ad248..e787d421fa8 100644
--- a/doc/workflow/slash_commands.md
+++ b/doc/workflow/slash_commands.md
@@ -12,9 +12,9 @@ do.
 | Command                    | Aliases             | Action       |
 |:---------------------------|:--------------------|:-------------|
 | `/close`                   | None                | Close the issue or merge request |
-| `/open`                    | `/reopen`           | Reopen the issue or merge request |
+| `/reopen`                  | `/open`             | Reopen the issue or merge request |
 | `/title <New title>`       | None                | Change title |
-| `/assign @username`        | `/reassign`         | Assign |
+| `/assign @username`        | None                | Assign |
 | `/unassign`                | `/remove_assignee`  | Remove assignee |
 | `/milestone %milestone`    | None                | Set milestone |
 | `/clear_milestone`         | `/remove_milestone` | Remove milestone |
@@ -25,5 +25,5 @@ do.
 | `/done`                    | None                | Mark todo as done |
 | `/subscribe`               | None                | Subscribe |
 | `/unsubscribe`             | None                | Unsubscribe |
-| `/due <in 2 days | this Friday | December 31st>` | `/due_date` | Set due date |
+| `/due <in 2 days; this Friday; December 31st>` | `/due_date` | Set due date |
 | `/clear_due_date`          | None                | Remove due date |

From 029b7d2e9266246feff2f165a10b16be1d7fe88e Mon Sep 17 00:00:00 2001
From: Douwe Maan <douwe@selenight.nl>
Date: Sat, 13 Aug 2016 11:58:51 -0500
Subject: [PATCH 20/25] Fixed specs and fixes based on failing specs

---
 app/controllers/projects/issues_controller.rb |   8 +-
 app/services/notes/create_service.rb          |  23 +-
 app/services/notes/slash_commands_service.rb  |  19 +-
 .../slash_commands/interpret_service.rb       |  79 +++----
 .../slash_commands/command_definition.rb      |  11 +-
 lib/gitlab/slash_commands/dsl.rb              |   5 +-
 lib/gitlab/slash_commands/extractor.rb        |  12 +-
 .../slash_commands/command_definition_spec.rb | 143 ++++++++++++
 spec/lib/gitlab/slash_commands/dsl_spec.rb    | 190 ++++------------
 .../gitlab/slash_commands/extractor_spec.rb   |  55 +++--
 spec/services/notes/create_service_spec.rb    |   2 +-
 .../notes/slash_commands_service_spec.rb      |  33 ++-
 .../slash_commands/interpret_service_spec.rb  | 203 +++---------------
 13 files changed, 360 insertions(+), 423 deletions(-)
 create mode 100644 spec/lib/gitlab/slash_commands/command_definition_spec.rb

diff --git a/app/controllers/projects/issues_controller.rb b/app/controllers/projects/issues_controller.rb
index c8eda6b27f4..d0cc4b55467 100644
--- a/app/controllers/projects/issues_controller.rb
+++ b/app/controllers/projects/issues_controller.rb
@@ -176,12 +176,7 @@ class Projects::IssuesController < Projects::ApplicationController
   protected
 
   def issue
-    @noteable = @issue ||=
-      begin
-        @project.issues.find_by!(iid: params[:id])
-      rescue ActiveRecord::RecordNotFound
-        redirect_old
-      end
+    @noteable = @issue ||= @project.issues.find_by(iid: params[:id]) || redirect_old
   end
   alias_method :subscribable_resource, :issue
   alias_method :issuable, :issue
@@ -225,7 +220,6 @@ class Projects::IssuesController < Projects::ApplicationController
 
     if issue
       redirect_to issue_path(issue)
-      return
     else
       raise ActiveRecord::RecordNotFound.new
     end
diff --git a/app/services/notes/create_service.rb b/app/services/notes/create_service.rb
index e9f37e04993..a36008c3ef5 100644
--- a/app/services/notes/create_service.rb
+++ b/app/services/notes/create_service.rb
@@ -15,20 +15,29 @@ module Notes
       # **before** we save the note because if the note consists of commands
       # only, there is no need be create a note!
       slash_commands_service = SlashCommandsService.new(project, current_user)
-      content, command_params = slash_commands_service.extract_commands(note)
 
-      note.note = content
+      if slash_commands_service.supported?(note)
+        content, command_params = slash_commands_service.extract_commands(note)
 
-      if note.save
+        only_commands = content.empty?
+
+        note.note = content
+      end
+
+      if !only_commands && note.save
         # Finish the harder work in the background
         NewNoteWorker.perform_in(2.seconds, note.id, params)
         todo_service.new_note(note, current_user)
       end
 
-      # We must add the error after we call #save because errors are reset
-      # when #save is called
-      if slash_commands_service.execute(command_params, note) && note.note.blank?
-        note.errors.add(:commands_only, 'Your commands have been executed!')
+      if command_params && command_params.any?
+        slash_commands_service.execute(command_params, note)
+
+        # We must add the error after we call #save because errors are reset
+        # when #save is called
+        if only_commands
+          note.errors.add(:commands_only, 'Your commands have been executed!')
+        end
       end
 
       note
diff --git a/app/services/notes/slash_commands_service.rb b/app/services/notes/slash_commands_service.rb
index f2c43775b72..4a9a8a64653 100644
--- a/app/services/notes/slash_commands_service.rb
+++ b/app/services/notes/slash_commands_service.rb
@@ -5,10 +5,13 @@ module Notes
       'MergeRequest' => MergeRequests::UpdateService
     }
 
+    def supported?(note)
+      noteable_update_service(note) &&
+        can?(current_user, :"update_#{note.noteable_type.underscore}", note.noteable)
+    end
+
     def extract_commands(note)
-      @noteable_update_service = UPDATE_SERVICES[note.noteable_type]
-      return [] unless @noteable_update_service
-      return [] unless can?(current_user, :"update_#{note.noteable_type.underscore}", note.noteable)
+      return [note.note, {}] unless supported?(note)
 
       SlashCommands::InterpretService.new(project, current_user).
         execute(note.note, note.noteable)
@@ -16,9 +19,15 @@ module Notes
 
     def execute(command_params, note)
       return if command_params.empty?
+      return unless supported?(note)
 
-      @noteable_update_service.new(project, current_user, command_params).
-        execute(note.noteable)
+      noteable_update_service(note).new(project, current_user, command_params).execute(note.noteable)
+    end
+
+    private
+
+    def noteable_update_service(note)
+      UPDATE_SERVICES[note.noteable_type]
     end
   end
 end
diff --git a/app/services/slash_commands/interpret_service.rb b/app/services/slash_commands/interpret_service.rb
index f7b9547bd2b..126f97b0f9b 100644
--- a/app/services/slash_commands/interpret_service.rb
+++ b/app/services/slash_commands/interpret_service.rb
@@ -2,16 +2,16 @@ module SlashCommands
   class InterpretService < BaseService
     include Gitlab::SlashCommands::Dsl
 
-    attr_reader :noteable
+    attr_reader :issuable
 
     # Takes a text and interpret the commands that are extracted from it.
     # Returns a hash of changes to be applied to a record.
-    def execute(content, noteable)
-      @noteable = noteable
+    def execute(content, issuable)
+      @issuable = issuable
       @updates = {}
 
       opts = {
-        noteable:     noteable,
+        issuable:     issuable,
         current_user: current_user,
         project:      project
       }
@@ -35,23 +35,24 @@ module SlashCommands
     end
 
     desc do
-      "Close this #{noteable.to_ability_name.humanize(capitalize: false)}"
+      "Close this #{issuable.to_ability_name.humanize(capitalize: false)}"
     end
     condition do
-      noteable.persisted? &&
-        noteable.open? &&
-        current_user.can?(:"update_#{noteable.to_ability_name}", noteable)
+      issuable.persisted? &&
+        issuable.open? &&
+        current_user.can?(:"update_#{issuable.to_ability_name}", issuable)
     end
     command :close do
       @updates[:state_event] = 'close'
     end
 
     desc do
-      "Reopen this #{noteable.to_ability_name.humanize(capitalize: false)}"
+      "Reopen this #{issuable.to_ability_name.humanize(capitalize: false)}"
     end
     condition do
-      noteable.closed? &&
-        current_user.can?(:"update_#{noteable.to_ability_name}", noteable)
+      issuable.persisted? &&
+        issuable.closed? &&
+        current_user.can?(:"update_#{issuable.to_ability_name}", issuable)
     end
     command :reopen, :open do
       @updates[:state_event] = 'reopen'
@@ -60,8 +61,8 @@ module SlashCommands
     desc 'Change title'
     params '<New title>'
     condition do
-      noteable.persisted? &&
-        current_user.can?(:"update_#{noteable.to_ability_name}", noteable)
+      issuable.persisted? &&
+        current_user.can?(:"update_#{issuable.to_ability_name}", issuable)
     end
     command :title do |title_param|
       @updates[:title] = title_param
@@ -70,7 +71,7 @@ module SlashCommands
     desc 'Assign'
     params '@user'
     condition do
-      current_user.can?(:"admin_#{noteable.to_ability_name}", project)
+      current_user.can?(:"admin_#{issuable.to_ability_name}", project)
     end
     command :assign do |assignee_param|
       user = extract_references(assignee_param, :user).first
@@ -82,8 +83,9 @@ module SlashCommands
 
     desc 'Remove assignee'
     condition do
-      noteable.assignee_id? &&
-        current_user.can?(:"admin_#{noteable.to_ability_name}", project)
+      issuable.persisted? &&
+        issuable.assignee_id? &&
+        current_user.can?(:"admin_#{issuable.to_ability_name}", project)
     end
     command :unassign, :remove_assignee do
       @updates[:assignee_id] = nil
@@ -92,7 +94,7 @@ module SlashCommands
     desc 'Set milestone'
     params '%"milestone"'
     condition do
-      current_user.can?(:"admin_#{noteable.to_ability_name}", project) &&
+      current_user.can?(:"admin_#{issuable.to_ability_name}", project) &&
         project.milestones.active.any?
     end
     command :milestone do |milestone_param|
@@ -104,8 +106,9 @@ module SlashCommands
 
     desc 'Remove milestone'
     condition do
-      noteable.milestone_id? &&
-        current_user.can?(:"admin_#{noteable.to_ability_name}", project)
+      issuable.persisted? &&
+        issuable.milestone_id? &&
+        current_user.can?(:"admin_#{issuable.to_ability_name}", project)
     end
     command :clear_milestone, :remove_milestone do
       @updates[:milestone_id] = nil
@@ -114,7 +117,7 @@ module SlashCommands
     desc 'Add label(s)'
     params '~label1 ~"label 2"'
     condition do
-      current_user.can?(:"admin_#{noteable.to_ability_name}", project) &&
+      current_user.can?(:"admin_#{issuable.to_ability_name}", project) &&
         project.labels.any?
     end
     command :label, :labels do |labels_param|
@@ -126,8 +129,9 @@ module SlashCommands
     desc 'Remove label(s)'
     params '~label1 ~"label 2"'
     condition do
-      noteable.labels.any? &&
-        current_user.can?(:"admin_#{noteable.to_ability_name}", project)
+      issuable.persisted? &&
+        issuable.labels.any? &&
+        current_user.can?(:"admin_#{issuable.to_ability_name}", project)
     end
     command :unlabel, :remove_label, :remove_labels do |labels_param|
       label_ids = find_label_ids(labels_param)
@@ -137,8 +141,9 @@ module SlashCommands
 
     desc 'Remove all labels'
     condition do
-      noteable.labels.any? &&
-        current_user.can?(:"admin_#{noteable.to_ability_name}", project)
+      issuable.persisted? &&
+        issuable.labels.any? &&
+        current_user.can?(:"admin_#{issuable.to_ability_name}", project)
     end
     command :clear_labels, :clear_label do
       @updates[:label_ids] = []
@@ -146,8 +151,8 @@ module SlashCommands
 
     desc 'Add a todo'
     condition do
-      noteable.persisted? &&
-        !TodoService.new.todo_exist?(noteable, current_user)
+      issuable.persisted? &&
+        !TodoService.new.todo_exist?(issuable, current_user)
     end
     command :todo do
       @updates[:todo_event] = 'add'
@@ -155,7 +160,8 @@ module SlashCommands
 
     desc 'Mark todo as done'
     condition do
-        TodoService.new.todo_exist?(noteable, current_user)
+      issuable.persisted? &&
+        TodoService.new.todo_exist?(issuable, current_user)
     end
     command :done do
       @updates[:todo_event] = 'done'
@@ -163,8 +169,8 @@ module SlashCommands
 
     desc 'Subscribe'
     condition do
-      noteable.persisted? &&
-        !noteable.subscribed?(current_user)
+      issuable.persisted? &&
+        !issuable.subscribed?(current_user)
     end
     command :subscribe do
       @updates[:subscription_event] = 'subscribe'
@@ -172,8 +178,8 @@ module SlashCommands
 
     desc 'Unsubscribe'
     condition do
-      noteable.persisted? &&
-        noteable.subscribed?(current_user)
+      issuable.persisted? &&
+        issuable.subscribed?(current_user)
     end
     command :unsubscribe do
       @updates[:subscription_event] = 'unsubscribe'
@@ -182,8 +188,8 @@ module SlashCommands
     desc 'Set due date'
     params '<in 2 days; this Friday; December 31st>'
     condition do
-      noteable.respond_to?(:due_date) &&
-        current_user.can?(:"update_#{noteable.to_ability_name}", noteable)
+      issuable.respond_to?(:due_date) &&
+        current_user.can?(:"update_#{issuable.to_ability_name}", issuable)
     end
     command :due, :due_date do |due_date_param|
       due_date = Chronic.parse(due_date_param).try(:to_date)
@@ -193,9 +199,10 @@ module SlashCommands
 
     desc 'Remove due date'
     condition do
-      noteable.respond_to?(:due_date) &&
-        noteable.due_date? &&
-        current_user.can?(:"update_#{noteable.to_ability_name}", noteable)
+      issuable.persisted? &&
+        issuable.respond_to?(:due_date) &&
+        issuable.due_date? &&
+        current_user.can?(:"update_#{issuable.to_ability_name}", issuable)
     end
     command :clear_due_date do
       @updates[:due_date] = nil
diff --git a/lib/gitlab/slash_commands/command_definition.rb b/lib/gitlab/slash_commands/command_definition.rb
index 5dec6c91869..187c1c9489f 100644
--- a/lib/gitlab/slash_commands/command_definition.rb
+++ b/lib/gitlab/slash_commands/command_definition.rb
@@ -3,8 +3,8 @@ module Gitlab
     class CommandDefinition
       attr_accessor :name, :aliases, :description, :params, :condition_block, :action_block
 
-      def valid?
-        name.present?
+      def initialize(name)
+        @name = name
       end
 
       def all_names
@@ -22,13 +22,6 @@ module Gitlab
         context.instance_exec(&condition_block)
       end
 
-      def to_description(opts)
-        return description unless description.respond_to?(:call)
-
-        context = OpenStruct.new(opts)
-        context.instance_exec(&description) rescue ''
-      end
-
       def execute(context, opts, *args)
         return if noop? || !available?(opts)
 
diff --git a/lib/gitlab/slash_commands/dsl.rb b/lib/gitlab/slash_commands/dsl.rb
index 58ba7027f84..7b1a094a7e6 100644
--- a/lib/gitlab/slash_commands/dsl.rb
+++ b/lib/gitlab/slash_commands/dsl.rb
@@ -73,16 +73,13 @@ module Gitlab
         def command(*command_names, &block)
           name, *aliases = command_names
 
-          definition = CommandDefinition.new
-          definition.name            =  name
+          definition = CommandDefinition.new(name)
           definition.aliases         =  aliases
           definition.description     =  @description || ''
           definition.params          =  @params || []
           definition.condition_block =  @condition_block
           definition.action_block    =  block
 
-          return unless definition.valid?
-
           self.command_definitions << definition
 
           definition.all_names.each do |name|
diff --git a/lib/gitlab/slash_commands/extractor.rb b/lib/gitlab/slash_commands/extractor.rb
index a6838cb5e7c..02c4c8c492e 100644
--- a/lib/gitlab/slash_commands/extractor.rb
+++ b/lib/gitlab/slash_commands/extractor.rb
@@ -29,8 +29,8 @@ module Gitlab
       # commands = extractor.extract_commands(msg) #=> [['labels', '~foo ~"bar baz"']]
       # msg #=> "hello\nworld"
       # ```
-      def extract_commands(content, opts)
-        return [] unless content
+      def extract_commands(content, opts = {})
+        return [content, []] unless content
 
         content = content.dup
 
@@ -107,7 +107,13 @@ module Gitlab
               # Command not in a blockquote, blockcode, or HTML tag:
               # /close
 
-              ^\/(?<cmd>#{Regexp.union(names)})(?:$|\ (?<args>[^\/\n]*)$)
+              ^\/
+              (?<cmd>#{Regexp.union(names)})
+              (?:
+                [ ]
+                (?<args>[^\/\n]*)
+              )?
+              (?:\n|$)
             )
         }mx
       end
diff --git a/spec/lib/gitlab/slash_commands/command_definition_spec.rb b/spec/lib/gitlab/slash_commands/command_definition_spec.rb
new file mode 100644
index 00000000000..2a75fab24b0
--- /dev/null
+++ b/spec/lib/gitlab/slash_commands/command_definition_spec.rb
@@ -0,0 +1,143 @@
+require 'spec_helper'
+
+describe Gitlab::SlashCommands::CommandDefinition do
+  subject { described_class.new(:command) }
+
+  describe "#all_names" do
+    context "when the command has aliases" do
+      before do
+        subject.aliases = [:alias1, :alias2]
+      end
+
+      it "returns an array with the name and aliases" do
+        expect(subject.all_names).to eq([:command, :alias1, :alias2])
+      end
+    end
+
+    context "when the command doesn't have aliases" do
+      it "returns an array with the name" do
+        expect(subject.all_names).to eq([:command])
+      end
+    end
+  end
+
+  describe "#noop?" do
+    context "when the command has an action block" do
+      before do
+        subject.action_block = -> { }
+      end
+
+      it "returns false" do
+        expect(subject.noop?).to be false
+      end
+    end
+
+    context "when the command doesn't have an action block" do
+      it "returns true" do
+        expect(subject.noop?).to be true
+      end
+    end
+  end
+
+  describe "#available?" do
+    let(:opts) { { go: false } }
+
+    context "when the command has a condition block" do
+      before do
+        subject.condition_block = -> { go }
+      end
+
+      context "when the condition block returns true" do
+        before do
+          opts[:go] = true
+        end
+
+        it "returns true" do
+          expect(subject.available?(opts)).to be true
+        end
+      end
+
+      context "when the condition block returns false" do
+        it "returns false" do
+          expect(subject.available?(opts)).to be false
+        end
+      end
+    end
+
+    context "when the command doesn't have a condition block" do
+      it "returns true" do
+        expect(subject.available?(opts)).to be true
+      end
+    end
+  end
+
+  describe "#execute" do
+    let(:context) { OpenStruct.new(run: false) }
+
+    context "when the command is a noop" do
+      it "doesn't execute the command" do
+        expect(context).not_to receive(:instance_exec)
+
+        subject.execute(context, {})
+
+        expect(context.run).to be false
+      end
+    end
+
+    context "when the command is not a noop" do
+      before do
+        subject.action_block = -> { self.run = true }
+      end
+
+      context "when the command is not available" do
+        before do
+          subject.condition_block = -> { false }
+        end
+
+        it "doesn't execute the command" do
+          subject.execute(context, {})
+
+          expect(context.run).to be false
+        end
+      end
+
+      context "when the command is available" do
+        context "when the command has an exact number of arguments" do
+          before do
+            subject.action_block = ->(arg) { self.run = arg }
+          end
+
+          context "when the command is provided a wrong number of arguments" do
+            it "doesn't execute the command" do
+              subject.execute(context, {}, true, true)
+
+              expect(context.run).to be false
+            end
+          end
+
+          context "when the command is provided the right number of arguments" do
+            it "executes the command" do
+              subject.execute(context, {}, true)
+
+              expect(context.run).to be true
+            end
+          end
+        end
+
+        context "when the command has a variable number of arguments" do
+          before do
+            subject.action_block = ->(*args) { self.run = args.first }
+          end
+
+          context "when the command is provided any number of arguments" do
+            it "executes the command" do
+              subject.execute(context, {}, true, true)
+
+              expect(context.run).to be true
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/slash_commands/dsl_spec.rb b/spec/lib/gitlab/slash_commands/dsl_spec.rb
index 500ff3ca1fe..87be3455baf 100644
--- a/spec/lib/gitlab/slash_commands/dsl_spec.rb
+++ b/spec/lib/gitlab/slash_commands/dsl_spec.rb
@@ -10,9 +10,9 @@ describe Gitlab::SlashCommands::Dsl do
         "Hello World!"
       end
 
-      desc 'A command returning a value'
+      desc { "A command with #{something}" }
       command :returning do
-        return 42
+        42
       end
 
       params 'The first argument'
@@ -28,7 +28,7 @@ describe Gitlab::SlashCommands::Dsl do
         [arg1, arg2]
       end
 
-      command :cc, noop: true
+      command :cc
 
       condition do
         project == 'foo'
@@ -49,182 +49,74 @@ describe Gitlab::SlashCommands::Dsl do
         {
           name: :no_args, aliases: [:none],
           description: 'A command with no args', params: [],
-          condition_block: nil, action_block: a_kind_of(Proc),
-          opts: {}
+          condition_block: nil, action_block: a_kind_of(Proc)
         },
         {
           name: :returning, aliases: [],
           description: 'A command returning a value', params: [],
-          condition_block: nil, action_block: a_kind_of(Proc),
-          opts: {}
+          condition_block: nil, action_block: a_kind_of(Proc)
         },
         {
           name: :one_arg, aliases: [:once, :first],
           description: '', params: ['The first argument'],
-          condition_block: nil, action_block: a_kind_of(Proc),
-          opts: {}
+          condition_block: nil, action_block: a_kind_of(Proc)
         },
         {
           name: :two_args, aliases: [],
           description: '', params: ['The first argument', 'The second argument'],
-          condition_block: nil, action_block: a_kind_of(Proc),
-          opts: {}
+          condition_block: nil, action_block: a_kind_of(Proc)
         },
         {
           name: :cc, aliases: [],
           description: '', params: [],
-          condition_block: nil, action_block: nil,
-          opts: { noop: true }
+          condition_block: nil, action_block: nil
         },
         {
           name: :wildcard, aliases: [],
           description: '', params: [],
-          condition_block: nil, action_block: a_kind_of(Proc),
-          opts: {}
+          condition_block: nil, action_block: a_kind_of(Proc)
         }
       ]
     end
 
     it 'returns an array with commands definitions' do
-      expect(DummyClass.command_definitions).to match_array base_expected
-    end
+      no_args_def, returning_def, one_arg_def, two_args_def, cc_def, cond_action_def, wildcard_def = DummyClass.command_definitions
 
-    context 'with options passed' do
-      context 'when condition is met' do
-        let(:expected) do
-          base_expected << {
-            name: :cond_action, aliases: [],
-            description: '', params: [],
-            condition_block: a_kind_of(Proc), action_block: a_kind_of(Proc),
-            opts: {}
-          }
-        end
+      expect(no_args_def.name).to eq(:no_args)
+      expect(no_args_def.aliases).to eq([:none])
+      expect(no_args_def.description).to eq('A command with no args')
+      expect(no_args_def.params).to eq([])
+      expect(no_args_def.condition_block).to be_nil
+      expect(no_args_def.action_block).to be_a_kind_of(Proc)
 
-        it 'returns an array with commands definitions' do
-          expect(DummyClass.command_definitions(project: 'foo')).to match_array expected
-        end
-      end
+      expect(returning_def.name).to eq(:returning)
+      expect(returning_def.aliases).to eq([])
+      expect(returning_def.description).to be_a_kind_of(Proc)
+      expect(returning_def.to_h(something: "a block description")[:description]).to eq('A command with a block description')
+      expect(returning_def.params).to eq([])
+      expect(returning_def.condition_block).to be_nil
+      expect(returning_def.action_block).to be_a_kind_of(Proc)
 
-      context 'when condition is not met' do
-        it 'returns an array with commands definitions without actions that did not met conditions' do
-          expect(DummyClass.command_definitions(project: 'bar')).to match_array base_expected
-        end
-      end
+      expect(one_arg_def.name).to eq(:one_arg)
+      expect(one_arg_def.aliases).to eq([:once, :first])
+      expect(one_arg_def.description).to eq('')
+      expect(one_arg_def.params).to eq(['The first argument'])
+      expect(one_arg_def.condition_block).to be_nil
+      expect(one_arg_def.action_block).to be_a_kind_of(Proc)
 
-      context 'when description can be generated dynamically' do
-        it 'returns an array with commands definitions with dynamic descriptions' do
-          base_expected[3][:description] = 'A dynamic description for MERGE REQUEST'
+      expect(cc_def.name).to eq(:cc)
+      expect(cc_def.aliases).to eq([])
+      expect(cc_def.description).to eq('')
+      expect(cc_def.params).to eq([])
+      expect(cc_def.condition_block).to be_nil
+      expect(cc_def.action_block).to be_nil
 
-          expect(DummyClass.command_definitions(noteable: 'merge request')).to match_array base_expected
-        end
-      end
-    end
-  end
-
-  describe '.command_names' do
-    let(:base_expected) do
-      [
-        :no_args, :none, :returning, :one_arg,
-        :once, :first, :two_args, :wildcard
-      ]
-    end
-
-    it 'returns an array with commands definitions' do
-      expect(DummyClass.command_names).to eq base_expected
-    end
-
-    context 'with options passed' do
-      context 'when condition is met' do
-        let(:expected) { base_expected << :cond_action }
-
-        it 'returns an array with commands definitions' do
-          expect(DummyClass.command_names(project: 'foo')).to match_array expected
-        end
-      end
-
-      context 'when condition is not met' do
-        it 'returns an array with commands definitions without action that did not met conditions' do
-          expect(DummyClass.command_names(project: 'bar')).to match_array base_expected
-        end
-      end
-    end
-  end
-
-  let(:dummy) { DummyClass.new(nil) }
-
-  describe '#execute_command' do
-    describe 'command with no args' do
-      context 'called with no args' do
-        it 'succeeds' do
-          expect(dummy.execute_command(:no_args)).to eq 'Hello World!'
-        end
-      end
-    end
-
-    describe 'command with an explicit return' do
-      context 'called with no args' do
-        it 'succeeds' do
-          expect { dummy.execute_command(:returning) }.to raise_error(LocalJumpError)
-        end
-      end
-    end
-
-    describe 'command with one arg' do
-      context 'called with one arg' do
-        it 'succeeds' do
-          expect(dummy.execute_command(:one_arg, 42)).to eq 42
-        end
-      end
-    end
-
-    describe 'command with two args' do
-      context 'called with two args' do
-        it 'succeeds' do
-          expect(dummy.execute_command(:two_args, 42, 'foo')).to eq [42, 'foo']
-        end
-      end
-    end
-
-    describe 'noop command' do
-      it 'returns nil' do
-        expect(dummy.execute_command(:cc)).to be_nil
-      end
-    end
-
-    describe 'command with condition' do
-      context 'when condition is not met' do
-        it 'returns nil' do
-          expect(dummy.execute_command(:cond_action)).to be_nil
-        end
-      end
-
-      context 'when condition is met' do
-        let(:dummy) { DummyClass.new('foo') }
-
-        it 'succeeds' do
-          expect(dummy.execute_command(:cond_action, 42)).to eq 42
-        end
-      end
-    end
-
-    describe 'command with wildcard' do
-      context 'called with no args' do
-        it 'succeeds' do
-          expect(dummy.execute_command(:wildcard)).to eq []
-        end
-      end
-
-      context 'called with one arg' do
-        it 'succeeds' do
-          expect(dummy.execute_command(:wildcard, 42)).to eq [42]
-        end
-      end
-
-      context 'called with two args' do
-        it 'succeeds' do
-          expect(dummy.execute_command(:wildcard, 42, 'foo')).to eq [42, 'foo']
-        end
-      end
+      expect(wildcard_def.name).to eq(:wildcard)
+      expect(wildcard_def.aliases).to eq([])
+      expect(wildcard_def.description).to eq('')
+      expect(wildcard_def.params).to eq([])
+      expect(wildcard_def.condition_block).to be_nil
+      expect(wildcard_def.action_block).to be_a_kind_of(Proc)
     end
   end
 end
diff --git a/spec/lib/gitlab/slash_commands/extractor_spec.rb b/spec/lib/gitlab/slash_commands/extractor_spec.rb
index 8a6801205fa..09f909dcdd2 100644
--- a/spec/lib/gitlab/slash_commands/extractor_spec.rb
+++ b/spec/lib/gitlab/slash_commands/extractor_spec.rb
@@ -1,32 +1,43 @@
 require 'spec_helper'
 
 describe Gitlab::SlashCommands::Extractor do
-  let(:extractor) { described_class.new([:open, :assign, :labels, :power]) }
+  let(:definitions) do
+    Class.new do
+      include Gitlab::SlashCommands::Dsl
+
+      command(:reopen, :open) { }
+      command(:assign) { }
+      command(:labels) { }
+      command(:power) { }
+    end.command_definitions
+  end
+
+  let(:extractor) { described_class.new(definitions) }
 
   shared_examples 'command with no argument' do
     it 'extracts command' do
-      commands = extractor.extract_commands(original_msg)
+      msg, commands = extractor.extract_commands(original_msg)
 
       expect(commands).to eq [['open']]
-      expect(original_msg).to eq final_msg
+      expect(msg).to eq final_msg
     end
   end
 
   shared_examples 'command with a single argument' do
     it 'extracts command' do
-      commands = extractor.extract_commands(original_msg)
+      msg, commands = extractor.extract_commands(original_msg)
 
       expect(commands).to eq [['assign', '@joe']]
-      expect(original_msg).to eq final_msg
+      expect(msg).to eq final_msg
     end
   end
 
   shared_examples 'command with multiple arguments' do
     it 'extracts command' do
-      commands = extractor.extract_commands(original_msg)
+      msg, commands = extractor.extract_commands(original_msg)
 
       expect(commands).to eq [['labels', '~foo ~"bar baz" label']]
-      expect(original_msg).to eq final_msg
+      expect(msg).to eq final_msg
     end
   end
 
@@ -49,7 +60,7 @@ describe Gitlab::SlashCommands::Extractor do
       context 'in the middle of a line' do
         it 'does not extract command' do
           msg = "hello\nworld /open"
-          commands = extractor.extract_commands(msg)
+          msg, commands = extractor.extract_commands(msg)
 
           expect(commands).to be_empty
           expect(msg).to eq "hello\nworld /open"
@@ -59,7 +70,7 @@ describe Gitlab::SlashCommands::Extractor do
       context 'at the end of content' do
         it_behaves_like 'command with no argument' do
           let(:original_msg) { "hello\n/open" }
-          let(:final_msg) { "hello\n" }
+          let(:final_msg) { "hello" }
         end
       end
     end
@@ -82,7 +93,7 @@ describe Gitlab::SlashCommands::Extractor do
       context 'in the middle of a line' do
         it 'does not extract command' do
           msg = "hello\nworld /assign @joe"
-          commands = extractor.extract_commands(msg)
+          msg, commands = extractor.extract_commands(msg)
 
           expect(commands).to be_empty
           expect(msg).to eq "hello\nworld /assign @joe"
@@ -92,14 +103,14 @@ describe Gitlab::SlashCommands::Extractor do
       context 'at the end of content' do
         it_behaves_like 'command with a single argument' do
           let(:original_msg) { "hello\n/assign @joe" }
-          let(:final_msg) { "hello\n" }
+          let(:final_msg) { "hello" }
         end
       end
 
       context 'when argument is not separated with a space' do
         it 'does not extract command' do
           msg = "hello\n/assign@joe\nworld"
-          commands = extractor.extract_commands(msg)
+          msg, commands = extractor.extract_commands(msg)
 
           expect(commands).to be_empty
           expect(msg).to eq "hello\n/assign@joe\nworld"
@@ -125,7 +136,7 @@ describe Gitlab::SlashCommands::Extractor do
       context 'in the middle of a line' do
         it 'does not extract command' do
           msg = %(hello\nworld /labels ~foo ~"bar baz" label)
-          commands = extractor.extract_commands(msg)
+          msg, commands = extractor.extract_commands(msg)
 
           expect(commands).to be_empty
           expect(msg).to eq %(hello\nworld /labels ~foo ~"bar baz" label)
@@ -135,14 +146,14 @@ describe Gitlab::SlashCommands::Extractor do
       context 'at the end of content' do
         it_behaves_like 'command with multiple arguments' do
           let(:original_msg) { %(hello\n/labels ~foo ~"bar baz" label) }
-          let(:final_msg) { "hello\n" }
+          let(:final_msg) { "hello" }
         end
       end
 
       context 'when argument is not separated with a space' do
         it 'does not extract command' do
           msg = %(hello\n/labels~foo ~"bar baz" label\nworld)
-          commands = extractor.extract_commands(msg)
+          msg, commands = extractor.extract_commands(msg)
 
           expect(commands).to be_empty
           expect(msg).to eq %(hello\n/labels~foo ~"bar baz" label\nworld)
@@ -152,7 +163,7 @@ describe Gitlab::SlashCommands::Extractor do
 
     it 'extracts command with multiple arguments and various prefixes' do
       msg = %(hello\n/power @user.name %9.10 ~"bar baz.2"\nworld)
-      commands = extractor.extract_commands(msg)
+      msg, commands = extractor.extract_commands(msg)
 
       expect(commands).to eq [['power', '@user.name %9.10 ~"bar baz.2"']]
       expect(msg).to eq "hello\nworld"
@@ -160,15 +171,15 @@ describe Gitlab::SlashCommands::Extractor do
 
     it 'extracts multiple commands' do
       msg = %(hello\n/power @user.name %9.10 ~"bar baz.2" label\nworld\n/open)
-      commands = extractor.extract_commands(msg)
+      msg, commands = extractor.extract_commands(msg)
 
       expect(commands).to eq [['power', '@user.name %9.10 ~"bar baz.2" label'], ['open']]
-      expect(msg).to eq "hello\nworld\n"
+      expect(msg).to eq "hello\nworld"
     end
 
     it 'does not alter original content if no command is found' do
       msg = 'Fixes #123'
-      commands = extractor.extract_commands(msg)
+      msg, commands = extractor.extract_commands(msg)
 
       expect(commands).to be_empty
       expect(msg).to eq 'Fixes #123'
@@ -177,7 +188,7 @@ describe Gitlab::SlashCommands::Extractor do
     it 'does not extract commands inside a blockcode' do
       msg = "Hello\r\n```\r\nThis is some text\r\n/close\r\n/assign @user\r\n```\r\n\r\nWorld"
       expected = msg.delete("\r")
-      commands = extractor.extract_commands(msg)
+      msg, commands = extractor.extract_commands(msg)
 
       expect(commands).to be_empty
       expect(msg).to eq expected
@@ -186,7 +197,7 @@ describe Gitlab::SlashCommands::Extractor do
     it 'does not extract commands inside a blockquote' do
       msg = "Hello\r\n>>>\r\nThis is some text\r\n/close\r\n/assign @user\r\n>>>\r\n\r\nWorld"
       expected = msg.delete("\r")
-      commands = extractor.extract_commands(msg)
+      msg, commands = extractor.extract_commands(msg)
 
       expect(commands).to be_empty
       expect(msg).to eq expected
@@ -195,7 +206,7 @@ describe Gitlab::SlashCommands::Extractor do
     it 'does not extract commands inside a HTML tag' do
       msg = "Hello\r\n<div>\r\nThis is some text\r\n/close\r\n/assign @user\r\n</div>\r\n\r\nWorld"
       expected = msg.delete("\r")
-      commands = extractor.extract_commands(msg)
+      msg, commands = extractor.extract_commands(msg)
 
       expect(commands).to be_empty
       expect(msg).to eq expected
diff --git a/spec/services/notes/create_service_spec.rb b/spec/services/notes/create_service_spec.rb
index 92dbccf0729..93885c84dc3 100644
--- a/spec/services/notes/create_service_spec.rb
+++ b/spec/services/notes/create_service_spec.rb
@@ -56,7 +56,7 @@ describe Notes::CreateService, services: true do
 
     it "creates regular note if emoji name is invalid" do
       opts = {
-        note: ':smile: moretext: ',
+        note: ':smile: moretext:',
         noteable_type: 'Issue',
         noteable_id: issue.id
       }
diff --git a/spec/services/notes/slash_commands_service_spec.rb b/spec/services/notes/slash_commands_service_spec.rb
index 5632ec09834..9a262fcf32f 100644
--- a/spec/services/notes/slash_commands_service_spec.rb
+++ b/spec/services/notes/slash_commands_service_spec.rb
@@ -12,7 +12,6 @@ describe Notes::SlashCommandsService, services: true do
 
     before do
       note.note = note_text
-      described_class.new(project, master).execute(note)
     end
 
     describe 'note with only command' do
@@ -20,7 +19,10 @@ describe Notes::SlashCommandsService, services: true do
         let(:note_text) { %(/close\n/assign @#{assignee.username}") }
 
         it 'saves the note and does not alter the note text' do
-          expect(note.note).to eq note_text
+          content, command_params = service.extract_commands(note)
+
+          expect(content).to eq note_text
+          expect(command_params).to be_empty
         end
       end
     end
@@ -30,7 +32,10 @@ describe Notes::SlashCommandsService, services: true do
         let(:note_text) { %(HELLO\n/close\n/assign @#{assignee.username}\nWORLD) }
 
         it 'saves the note and does not alter the note text' do
-          expect(note.note).to eq note_text
+          content, command_params = service.extract_commands(note)
+
+          expect(content).to eq note_text
+          expect(command_params).to be_empty
         end
       end
     end
@@ -53,9 +58,10 @@ describe Notes::SlashCommandsService, services: true do
         end
 
         it 'closes noteable, sets labels, assigns, and sets milestone to noteable, and leave no note' do
-          described_class.new(project, master).execute(note)
+          content, command_params = service.extract_commands(note)
+          service.execute(command_params, note)
 
-          expect(note.note).to eq ''
+          expect(content).to eq ''
           expect(note.noteable).to be_closed
           expect(note.noteable.labels).to match_array(labels)
           expect(note.noteable.assignee).to eq(assignee)
@@ -71,9 +77,10 @@ describe Notes::SlashCommandsService, services: true do
         let(:note_text) { '/open' }
 
         it 'opens the noteable, and leave no note' do
-          described_class.new(project, master).execute(note)
+          content, command_params = service.extract_commands(note)
+          service.execute(command_params, note)
 
-          expect(note.note).to eq ''
+          expect(content).to eq ''
           expect(note.noteable).to be_open
         end
       end
@@ -86,9 +93,10 @@ describe Notes::SlashCommandsService, services: true do
         end
 
         it 'closes noteable, sets labels, assigns, and sets milestone to noteable' do
-          described_class.new(project, master).execute(note)
+          content, command_params = service.extract_commands(note)
+          service.execute(command_params, note)
 
-          expect(note.note).to eq "HELLO\nWORLD"
+          expect(content).to eq "HELLO\nWORLD"
           expect(note.noteable).to be_closed
           expect(note.noteable.labels).to match_array(labels)
           expect(note.noteable.assignee).to eq(assignee)
@@ -104,9 +112,10 @@ describe Notes::SlashCommandsService, services: true do
         let(:note_text) { "HELLO\n/open\nWORLD" }
 
         it 'opens the noteable' do
-          described_class.new(project, master).execute(note)
+          content, command_params = service.extract_commands(note)
+          service.execute(command_params, note)
 
-          expect(note.note).to eq "HELLO\nWORLD"
+          expect(content).to eq "HELLO\nWORLD"
           expect(note.noteable).to be_open
         end
       end
@@ -114,6 +123,8 @@ describe Notes::SlashCommandsService, services: true do
   end
 
   describe '#execute' do
+    let(:service) { described_class.new(project, master) }
+
     it_behaves_like 'note on noteable that supports slash commands' do
       let(:note) { build(:note_on_issue, project: project) }
     end
diff --git a/spec/services/slash_commands/interpret_service_spec.rb b/spec/services/slash_commands/interpret_service_spec.rb
index 0cf77e53435..c20aa90ddde 100644
--- a/spec/services/slash_commands/interpret_service_spec.rb
+++ b/spec/services/slash_commands/interpret_service_spec.rb
@@ -12,141 +12,6 @@ describe SlashCommands::InterpretService, services: true do
     project.team << [user, :developer]
   end
 
-  describe '#command_names' do
-    subject do
-      described_class.command_names(
-        project: project,
-        noteable: issue,
-        current_user: user
-      )
-    end
-
-    it 'returns the basic known commands' do
-      is_expected.to match_array([
-        :close,
-        :title,
-        :assign, :reassign,
-        :todo,
-        :subscribe,
-        :due_date, :due
-      ])
-    end
-
-    context 'when noteable is open' do
-      it 'includes the :close command' do
-        is_expected.to include(*[:close])
-      end
-    end
-
-    context 'when noteable is closed' do
-      before do
-        issue.close!
-      end
-
-      it 'includes the :open, :reopen commands' do
-        is_expected.to include(*[:open, :reopen])
-      end
-    end
-
-    context 'when noteable has an assignee' do
-      before do
-        issue.update(assignee_id: user.id)
-      end
-
-      it 'includes the :unassign, :remove_assignee commands' do
-        is_expected.to include(*[:unassign, :remove_assignee])
-      end
-    end
-
-    context 'when noteable has a milestone' do
-      before do
-        issue.update(milestone: milestone)
-      end
-
-      it 'includes the :clear_milestone, :remove_milestone commands' do
-        is_expected.to include(*[:milestone, :clear_milestone, :remove_milestone])
-      end
-    end
-
-    context 'when project has a milestone' do
-      before do
-        milestone
-      end
-
-      it 'includes the :milestone command' do
-        is_expected.to include(*[:milestone])
-      end
-    end
-
-    context 'when noteable has a label' do
-      before do
-        issue.update(label_ids: [bug.id])
-      end
-
-      it 'includes the :unlabel, :remove_labels, :remove_label, :clear_labels, :clear_label commands' do
-        is_expected.to include(*[:unlabel, :remove_labels, :remove_label, :clear_labels, :clear_label])
-      end
-    end
-
-    context 'when project has a label' do
-      before do
-        inprogress
-      end
-
-      it 'includes the :labels, :label commands' do
-        is_expected.to include(*[:labels, :label])
-      end
-    end
-
-    context 'when user has no todo' do
-      it 'includes the :todo command' do
-        is_expected.to include(*[:todo])
-      end
-    end
-
-    context 'when user has a todo' do
-      before do
-        TodoService.new.mark_todo(issue, user)
-      end
-
-      it 'includes the :done command' do
-        is_expected.to include(*[:done])
-      end
-    end
-
-    context 'when user is not subscribed' do
-      it 'includes the :subscribe command' do
-        is_expected.to include(*[:subscribe])
-      end
-    end
-
-    context 'when user is subscribed' do
-      before do
-        issue.subscribe(user)
-      end
-
-      it 'includes the :unsubscribe command' do
-        is_expected.to include(*[:unsubscribe])
-      end
-    end
-
-    context 'when noteable has a no due date' do
-      it 'includes the :due_date, :due commands' do
-        is_expected.to include(*[:due_date, :due])
-      end
-    end
-
-    context 'when noteable has a due date' do
-      before do
-        issue.update(due_date: Date.today)
-      end
-
-      it 'includes the :clear_due_date command' do
-        is_expected.to include(*[:due_date, :due, :clear_due_date])
-      end
-    end
-  end
-
   describe '#execute' do
     let(:service) { described_class.new(project, user) }
     let(:merge_request) { create(:merge_request, source_project: project) }
@@ -154,60 +19,60 @@ describe SlashCommands::InterpretService, services: true do
     shared_examples 'open command' do
       it 'returns state_event: "open" if content contains /open' do
         issuable.close!
-        changes = service.execute(content, issuable)
+        _, updates = service.execute(content, issuable)
 
-        expect(changes).to eq(state_event: 'reopen')
+        expect(updates).to eq(state_event: 'reopen')
       end
     end
 
     shared_examples 'close command' do
       it 'returns state_event: "close" if content contains /open' do
-        changes = service.execute(content, issuable)
+        _, updates = service.execute(content, issuable)
 
-        expect(changes).to eq(state_event: 'close')
+        expect(updates).to eq(state_event: 'close')
       end
     end
 
     shared_examples 'title command' do
       it 'populates title: "A brand new title" if content contains /title A brand new title' do
-        changes = service.execute(content, issuable)
+        _, updates = service.execute(content, issuable)
 
-        expect(changes).to eq(title: 'A brand new title')
+        expect(updates).to eq(title: 'A brand new title')
       end
     end
 
     shared_examples 'assign command' do
       it 'fetches assignee and populates assignee_id if content contains /assign' do
-        changes = service.execute(content, issuable)
+        _, updates = service.execute(content, issuable)
 
-        expect(changes).to eq(assignee_id: user.id)
+        expect(updates).to eq(assignee_id: user.id)
       end
     end
 
     shared_examples 'unassign command' do
       it 'populates assignee_id: nil if content contains /unassign' do
         issuable.update(assignee_id: user.id)
-        changes = service.execute(content, issuable)
+        _, updates = service.execute(content, issuable)
 
-        expect(changes).to eq(assignee_id: nil)
+        expect(updates).to eq(assignee_id: nil)
       end
     end
 
     shared_examples 'milestone command' do
       it 'fetches milestone and populates milestone_id if content contains /milestone' do
         milestone # populate the milestone
-        changes = service.execute(content, issuable)
+        _, updates = service.execute(content, issuable)
 
-        expect(changes).to eq(milestone_id: milestone.id)
+        expect(updates).to eq(milestone_id: milestone.id)
       end
     end
 
     shared_examples 'clear_milestone command' do
       it 'populates milestone_id: nil if content contains /clear_milestone' do
         issuable.update(milestone_id: milestone.id)
-        changes = service.execute(content, issuable)
+        _, updates = service.execute(content, issuable)
 
-        expect(changes).to eq(milestone_id: nil)
+        expect(updates).to eq(milestone_id: nil)
       end
     end
 
@@ -215,86 +80,86 @@ describe SlashCommands::InterpretService, services: true do
       it 'fetches label ids and populates add_label_ids if content contains /label' do
         bug # populate the label
         inprogress # populate the label
-        changes = service.execute(content, issuable)
+        _, updates = service.execute(content, issuable)
 
-        expect(changes).to eq(add_label_ids: [bug.id, inprogress.id])
+        expect(updates).to eq(add_label_ids: [bug.id, inprogress.id])
       end
     end
 
     shared_examples 'unlabel command' do
       it 'fetches label ids and populates remove_label_ids if content contains /unlabel' do
         issuable.update(label_ids: [inprogress.id]) # populate the label
-        changes = service.execute(content, issuable)
+        _, updates = service.execute(content, issuable)
 
-        expect(changes).to eq(remove_label_ids: [inprogress.id])
+        expect(updates).to eq(remove_label_ids: [inprogress.id])
       end
     end
 
     shared_examples 'clear_labels command' do
       it 'populates label_ids: [] if content contains /clear_labels' do
         issuable.update(label_ids: [inprogress.id]) # populate the label
-        changes = service.execute(content, issuable)
+        _, updates = service.execute(content, issuable)
 
-        expect(changes).to eq(label_ids: [])
+        expect(updates).to eq(label_ids: [])
       end
     end
 
     shared_examples 'todo command' do
       it 'populates todo_event: "add" if content contains /todo' do
-        changes = service.execute(content, issuable)
+        _, updates = service.execute(content, issuable)
 
-        expect(changes).to eq(todo_event: 'add')
+        expect(updates).to eq(todo_event: 'add')
       end
     end
 
     shared_examples 'done command' do
       it 'populates todo_event: "done" if content contains /done' do
         TodoService.new.mark_todo(issuable, user)
-        changes = service.execute(content, issuable)
+        _, updates = service.execute(content, issuable)
 
-        expect(changes).to eq(todo_event: 'done')
+        expect(updates).to eq(todo_event: 'done')
       end
     end
 
     shared_examples 'subscribe command' do
       it 'populates subscription_event: "subscribe" if content contains /subscribe' do
-        changes = service.execute(content, issuable)
+        _, updates = service.execute(content, issuable)
 
-        expect(changes).to eq(subscription_event: 'subscribe')
+        expect(updates).to eq(subscription_event: 'subscribe')
       end
     end
 
     shared_examples 'unsubscribe command' do
       it 'populates subscription_event: "unsubscribe" if content contains /unsubscribe' do
         issuable.subscribe(user)
-        changes = service.execute(content, issuable)
+        _, updates = service.execute(content, issuable)
 
-        expect(changes).to eq(subscription_event: 'unsubscribe')
+        expect(updates).to eq(subscription_event: 'unsubscribe')
       end
     end
 
     shared_examples 'due_date command' do
       it 'populates due_date: Date.new(2016, 8, 28) if content contains /due_date 2016-08-28' do
-        changes = service.execute(content, issuable)
+        _, updates = service.execute(content, issuable)
 
-        expect(changes).to eq(due_date: defined?(expected_date) ? expected_date : Date.new(2016, 8, 28))
+        expect(updates).to eq(due_date: defined?(expected_date) ? expected_date : Date.new(2016, 8, 28))
       end
     end
 
     shared_examples 'clear_due_date command' do
       it 'populates due_date: nil if content contains /clear_due_date' do
         issuable.update(due_date: Date.today)
-        changes = service.execute(content, issuable)
+        _, updates = service.execute(content, issuable)
 
-        expect(changes).to eq(due_date: nil)
+        expect(updates).to eq(due_date: nil)
       end
     end
 
     shared_examples 'empty command' do
       it 'populates {} if content contains an unsupported command' do
-        changes = service.execute(content, issuable)
+        _, updates = service.execute(content, issuable)
 
-        expect(changes).to be_empty
+        expect(updates).to be_empty
       end
     end
 

From 8b8a4626c601a13683599fd1a127e2c502af38a3 Mon Sep 17 00:00:00 2001
From: Douwe Maan <douwe@selenight.nl>
Date: Tue, 16 Aug 2016 19:59:55 -0500
Subject: [PATCH 21/25] Fix specs and implement fixes based on failing specs

---
 app/controllers/projects_controller.rb        |  6 +-
 app/services/issuable_base_service.rb         | 41 ++++++++----
 app/services/issues/create_service.rb         |  7 +-
 app/services/merge_requests/create_service.rb |  2 +-
 app/services/projects/autocomplete_service.rb |  2 +-
 .../slash_commands/interpret_service.rb       |  4 +-
 doc/workflow/slash_commands.md                |  3 +-
 .../slash_commands/command_definition.rb      |  8 ++-
 lib/gitlab/slash_commands/dsl.rb              | 18 +++---
 spec/lib/gitlab/slash_commands/dsl_spec.rb    | 64 +++++--------------
 ...issuable_slash_commands_shared_examples.rb |  4 +-
 11 files changed, 75 insertions(+), 84 deletions(-)

diff --git a/app/controllers/projects_controller.rb b/app/controllers/projects_controller.rb
index 93338dba51e..fc52cd2f367 100644
--- a/app/controllers/projects_controller.rb
+++ b/app/controllers/projects_controller.rb
@@ -137,13 +137,13 @@ class ProjectsController < Projects::ApplicationController
     noteable =
       case params[:type]
       when 'Issue'
-        IssuesFinder.new(current_user, project_id: project.id, state: 'all').
+        IssuesFinder.new(current_user, project_id: @project.id, state: 'all').
           execute.find_by(iid: params[:type_id])
       when 'MergeRequest'
-        MergeRequestsFinder.new(current_user, project_id: project.id, state: 'all').
+        MergeRequestsFinder.new(current_user, project_id: @project.id, state: 'all').
           execute.find_by(iid: params[:type_id])
       when 'Commit'
-        project.commit(params[:type_id])
+        @project.commit(params[:type_id])
       else
         nil
       end
diff --git a/app/services/issuable_base_service.rb b/app/services/issuable_base_service.rb
index aa08eef081c..b60afd1560e 100644
--- a/app/services/issuable_base_service.rb
+++ b/app/services/issuable_base_service.rb
@@ -80,13 +80,16 @@ class IssuableBaseService < BaseService
     params[key] = project.labels.where(id: params[key]).pluck(:id)
   end
 
-  def process_label_ids(attributes, base_label_ids: [], merge_all: false)
+  def process_label_ids(attributes, existing_label_ids: [])
     label_ids = attributes.delete(:label_ids)
     add_label_ids = attributes.delete(:add_label_ids)
     remove_label_ids = attributes.delete(:remove_label_ids)
 
-    new_label_ids = base_label_ids
-    new_label_ids = label_ids if label_ids && (merge_all || (add_label_ids.blank? && remove_label_ids.blank?))
+    new_label_ids = existing_label_ids
+
+    override_existing = new_label_ids.empty? || (add_label_ids.blank? && remove_label_ids.blank?)
+    new_label_ids = label_ids if label_ids && override_existing
+
     new_label_ids |= add_label_ids if add_label_ids
     new_label_ids -= remove_label_ids if remove_label_ids
 
@@ -103,14 +106,8 @@ class IssuableBaseService < BaseService
     params.merge!(command_params)
   end
 
-  def create_issuable(issuable, attributes)
+  def create_issuable(issuable, attributes, label_ids:)
     issuable.with_transaction_returning_status do
-      attributes.delete(:state_event)
-      params[:author] ||= current_user
-      label_ids = process_label_ids(attributes, merge_all: true)
-
-      issuable.assign_attributes(attributes)
-
       if issuable.save
         issuable.update_attributes(label_ids: label_ids)
       end
@@ -121,8 +118,16 @@ class IssuableBaseService < BaseService
     merge_slash_commands_into_params!(issuable)
     filter_params
 
-    if params.present? && create_issuable(issuable, params)
-      handle_creation(issuable)
+    params.delete(:state_event)
+    params[:author] ||= current_user
+    label_ids = process_label_ids(params)
+
+    issuable.assign_attributes(params)
+
+    before_create(issuable)
+
+    if params.present? && create_issuable(issuable, params, label_ids: label_ids)
+      after_create(issuable)
       issuable.create_cross_references!(current_user)
       execute_hooks(issuable)
     end
@@ -130,10 +135,16 @@ class IssuableBaseService < BaseService
     issuable
   end
 
+  def before_create(issuable)
+    # To be overridden by subclasses
+  end
+
+  def after_create(issuable)
+    # To be overridden by subclasses
+  end
+
   def update_issuable(issuable, attributes)
     issuable.with_transaction_returning_status do
-      attributes[:label_ids] = process_label_ids(attributes, base_label_ids: issuable.label_ids)
-
       issuable.update(attributes.merge(updated_by: current_user))
     end
   end
@@ -145,6 +156,8 @@ class IssuableBaseService < BaseService
     filter_params
     old_labels = issuable.labels.to_a
 
+    params[:label_ids] = process_label_ids(params, existing_label_ids: issuable.label_ids)
+
     if params.present? && update_issuable(issuable, params)
       issuable.reset_events_cache
       handle_common_system_notes(issuable, old_labels: old_labels)
diff --git a/app/services/issues/create_service.rb b/app/services/issues/create_service.rb
index 8314c9971ff..ea1690f3e38 100644
--- a/app/services/issues/create_service.rb
+++ b/app/services/issues/create_service.rb
@@ -5,12 +5,15 @@ module Issues
       @api = params.delete(:api)
 
       @issue = project.issues.new
-      @issue.spam = spam_service.check(@api)
 
       create(@issue)
     end
 
-    def handle_creation(issuable)
+    def before_create(issuable)
+      issuable.spam = spam_service.check(@api)
+    end
+
+    def after_create(issuable)
       event_service.open_issue(issuable, current_user)
       notification_service.new_issue(issuable, current_user)
       todo_service.new_issue(issuable, current_user)
diff --git a/app/services/merge_requests/create_service.rb b/app/services/merge_requests/create_service.rb
index 0b592cd5620..73247e62421 100644
--- a/app/services/merge_requests/create_service.rb
+++ b/app/services/merge_requests/create_service.rb
@@ -16,7 +16,7 @@ module MergeRequests
       create(merge_request)
     end
 
-    def handle_creation(issuable)
+    def after_create(issuable)
       event_service.open_mr(issuable, current_user)
       notification_service.new_merge_request(issuable, current_user)
       todo_service.new_merge_request(issuable, current_user)
diff --git a/app/services/projects/autocomplete_service.rb b/app/services/projects/autocomplete_service.rb
index cb85ee6694d..f578f8dbea2 100644
--- a/app/services/projects/autocomplete_service.rb
+++ b/app/services/projects/autocomplete_service.rb
@@ -29,7 +29,7 @@ module Projects
 
       opts = {
         project: project,
-        noteable: noteable,
+        issuable: noteable,
         current_user: current_user
       }
       SlashCommands::InterpretService.command_definitions.map do |definition|
diff --git a/app/services/slash_commands/interpret_service.rb b/app/services/slash_commands/interpret_service.rb
index 126f97b0f9b..cb0dca94036 100644
--- a/app/services/slash_commands/interpret_service.rb
+++ b/app/services/slash_commands/interpret_service.rb
@@ -4,8 +4,8 @@ module SlashCommands
 
     attr_reader :issuable
 
-    # Takes a text and interpret the commands that are extracted from it.
-    # Returns a hash of changes to be applied to a record.
+    # Takes a text and interprets the commands that are extracted from it.
+    # Returns the content without commands, and hash of changes to be applied to a record.
     def execute(content, issuable)
       @issuable = issuable
       @updates = {}
diff --git a/doc/workflow/slash_commands.md b/doc/workflow/slash_commands.md
index e787d421fa8..75fec7bcdb9 100644
--- a/doc/workflow/slash_commands.md
+++ b/doc/workflow/slash_commands.md
@@ -4,7 +4,8 @@ Slash commands are textual shortcuts for common actions on issues or merge
 requests that are usually done by clicking buttons or dropdowns in GitLab's UI.
 You can enter these commands while creating a new issue or merge request, and
 in comments. Each command should be on a separate line in order to be properly
-detected and executed.
+detected and executed. The commands are removed from the issue, merge request or
+comment body before it is saved and will not be visible as such to anyone else.
 
 Here is a list of all of the available commands and descriptions about what they
 do.
diff --git a/lib/gitlab/slash_commands/command_definition.rb b/lib/gitlab/slash_commands/command_definition.rb
index 187c1c9489f..641c92e77da 100644
--- a/lib/gitlab/slash_commands/command_definition.rb
+++ b/lib/gitlab/slash_commands/command_definition.rb
@@ -3,8 +3,14 @@ module Gitlab
     class CommandDefinition
       attr_accessor :name, :aliases, :description, :params, :condition_block, :action_block
 
-      def initialize(name)
+      def initialize(name, attributes = {})
         @name = name
+
+        @aliases          =  attributes[:aliases] || []
+        @description      =  attributes[:description] || ''
+        @params           =  attributes[:params] || []
+        @condition_block  =  attributes[:condition_block]
+        @action_block     =  attributes[:action_block]
       end
 
       def all_names
diff --git a/lib/gitlab/slash_commands/dsl.rb b/lib/gitlab/slash_commands/dsl.rb
index 7b1a094a7e6..50b0937d267 100644
--- a/lib/gitlab/slash_commands/dsl.rb
+++ b/lib/gitlab/slash_commands/dsl.rb
@@ -17,7 +17,7 @@ module Gitlab
         # Allows to give a description to the next slash command.
         # This description is shown in the autocomplete menu.
         # It accepts a block that will be evaluated with the context given to
-        # `.command_definitions` or `.command_names`.
+        # `CommandDefintion#to_h`.
         #
         # Example:
         #
@@ -47,7 +47,7 @@ module Gitlab
         # Allows to define conditions that must be met in order for the command
         # to be returned by `.command_names` & `.command_definitions`.
         # It accepts a block that will be evaluated with the context given to
-        # `.command_definitions`, `.command_names`, and the actual command method.
+        # `CommandDefintion#to_h`.
         #
         # Example:
         #
@@ -73,12 +73,14 @@ module Gitlab
         def command(*command_names, &block)
           name, *aliases = command_names
 
-          definition = CommandDefinition.new(name)
-          definition.aliases         =  aliases
-          definition.description     =  @description || ''
-          definition.params          =  @params || []
-          definition.condition_block =  @condition_block
-          definition.action_block    =  block
+          definition = CommandDefinition.new(
+            name,
+            aliases:          aliases,
+            description:      @description,
+            params:           @params,
+            condition_block:  @condition_block,
+            action_block:     block
+          )
 
           self.command_definitions << definition
 
diff --git a/spec/lib/gitlab/slash_commands/dsl_spec.rb b/spec/lib/gitlab/slash_commands/dsl_spec.rb
index 87be3455baf..9ec00c25787 100644
--- a/spec/lib/gitlab/slash_commands/dsl_spec.rb
+++ b/spec/lib/gitlab/slash_commands/dsl_spec.rb
@@ -10,11 +10,6 @@ describe Gitlab::SlashCommands::Dsl do
         "Hello World!"
       end
 
-      desc { "A command with #{something}" }
-      command :returning do
-        42
-      end
-
       params 'The first argument'
       command :one_arg, :once, :first do |arg1|
         arg1
@@ -44,43 +39,8 @@ describe Gitlab::SlashCommands::Dsl do
   end
 
   describe '.command_definitions' do
-    let(:base_expected) do
-      [
-        {
-          name: :no_args, aliases: [:none],
-          description: 'A command with no args', params: [],
-          condition_block: nil, action_block: a_kind_of(Proc)
-        },
-        {
-          name: :returning, aliases: [],
-          description: 'A command returning a value', params: [],
-          condition_block: nil, action_block: a_kind_of(Proc)
-        },
-        {
-          name: :one_arg, aliases: [:once, :first],
-          description: '', params: ['The first argument'],
-          condition_block: nil, action_block: a_kind_of(Proc)
-        },
-        {
-          name: :two_args, aliases: [],
-          description: '', params: ['The first argument', 'The second argument'],
-          condition_block: nil, action_block: a_kind_of(Proc)
-        },
-        {
-          name: :cc, aliases: [],
-          description: '', params: [],
-          condition_block: nil, action_block: nil
-        },
-        {
-          name: :wildcard, aliases: [],
-          description: '', params: [],
-          condition_block: nil, action_block: a_kind_of(Proc)
-        }
-      ]
-    end
-
     it 'returns an array with commands definitions' do
-      no_args_def, returning_def, one_arg_def, two_args_def, cc_def, cond_action_def, wildcard_def = DummyClass.command_definitions
+      no_args_def, one_arg_def, two_args_def, cc_def, cond_action_def, wildcard_def = DummyClass.command_definitions
 
       expect(no_args_def.name).to eq(:no_args)
       expect(no_args_def.aliases).to eq([:none])
@@ -89,14 +49,6 @@ describe Gitlab::SlashCommands::Dsl do
       expect(no_args_def.condition_block).to be_nil
       expect(no_args_def.action_block).to be_a_kind_of(Proc)
 
-      expect(returning_def.name).to eq(:returning)
-      expect(returning_def.aliases).to eq([])
-      expect(returning_def.description).to be_a_kind_of(Proc)
-      expect(returning_def.to_h(something: "a block description")[:description]).to eq('A command with a block description')
-      expect(returning_def.params).to eq([])
-      expect(returning_def.condition_block).to be_nil
-      expect(returning_def.action_block).to be_a_kind_of(Proc)
-
       expect(one_arg_def.name).to eq(:one_arg)
       expect(one_arg_def.aliases).to eq([:once, :first])
       expect(one_arg_def.description).to eq('')
@@ -104,6 +56,13 @@ describe Gitlab::SlashCommands::Dsl do
       expect(one_arg_def.condition_block).to be_nil
       expect(one_arg_def.action_block).to be_a_kind_of(Proc)
 
+      expect(two_args_def.name).to eq(:two_args)
+      expect(two_args_def.aliases).to eq([])
+      expect(two_args_def.to_h(noteable: "issue")[:description]).to eq('A dynamic description for ISSUE')
+      expect(two_args_def.params).to eq(['The first argument', 'The second argument'])
+      expect(two_args_def.condition_block).to be_nil
+      expect(two_args_def.action_block).to be_a_kind_of(Proc)
+
       expect(cc_def.name).to eq(:cc)
       expect(cc_def.aliases).to eq([])
       expect(cc_def.description).to eq('')
@@ -111,6 +70,13 @@ describe Gitlab::SlashCommands::Dsl do
       expect(cc_def.condition_block).to be_nil
       expect(cc_def.action_block).to be_nil
 
+      expect(cond_action_def.name).to eq(:cond_action)
+      expect(cond_action_def.aliases).to eq([])
+      expect(cond_action_def.description).to eq('')
+      expect(cond_action_def.params).to eq([])
+      expect(cond_action_def.condition_block).to be_a_kind_of(Proc)
+      expect(cond_action_def.action_block).to be_a_kind_of(Proc)
+
       expect(wildcard_def.name).to eq(:wildcard)
       expect(wildcard_def.aliases).to eq([])
       expect(wildcard_def.description).to eq('')
diff --git a/spec/support/issuable_slash_commands_shared_examples.rb b/spec/support/issuable_slash_commands_shared_examples.rb
index ace14c19fd8..d2a49ea5c5e 100644
--- a/spec/support/issuable_slash_commands_shared_examples.rb
+++ b/spec/support/issuable_slash_commands_shared_examples.rb
@@ -28,7 +28,7 @@ shared_examples 'issuable record that supports slash commands in its description
 
         issuable = project.public_send(issuable_type.to_s.pluralize).first
 
-        expect(issuable.description).to eq "bug description\n"
+        expect(issuable.description).to eq "bug description"
         expect(issuable.labels).to eq [label_bug]
         expect(issuable.milestone).to eq milestone
         expect(page).to have_content 'bug 345'
@@ -57,7 +57,7 @@ shared_examples 'issuable record that supports slash commands in its description
         issuable.reload
         note = issuable.notes.user.first
 
-        expect(note.note).to eq "Awesome!\n"
+        expect(note.note).to eq "Awesome!"
         expect(issuable.assignee).to eq assignee
         expect(issuable.labels).to eq [label_bug]
         expect(issuable.milestone).to eq milestone

From 3e7eeefc939f2ce5234e36684c00b8d1c7e1c7dc Mon Sep 17 00:00:00 2001
From: Douwe Maan <douwe@selenight.nl>
Date: Wed, 17 Aug 2016 18:58:44 -0500
Subject: [PATCH 22/25] Address feedback

---
 app/services/issuable_base_service.rb           |  4 +---
 .../slash_commands/interpret_service.rb         |  5 ++---
 lib/gitlab/slash_commands/command_definition.rb | 16 ++++++++--------
 lib/gitlab/slash_commands/extractor.rb          | 17 ++++++++---------
 4 files changed, 19 insertions(+), 23 deletions(-)

diff --git a/app/services/issuable_base_service.rb b/app/services/issuable_base_service.rb
index b60afd1560e..57286f255f4 100644
--- a/app/services/issuable_base_service.rb
+++ b/app/services/issuable_base_service.rb
@@ -193,9 +193,7 @@ class IssuableBaseService < BaseService
       todo_service.mark_todo(issuable, current_user)
     when 'done'
       todo = TodosFinder.new(current_user).execute.find_by(target: issuable)
-      if todo
-        todo_service.mark_todos_as_done([todo], current_user)
-      end
+      todo_service.mark_todos_as_done([todo], current_user) if todo
     end
   end
 
diff --git a/app/services/slash_commands/interpret_service.rb b/app/services/slash_commands/interpret_service.rb
index cb0dca94036..dc4a892b8b1 100644
--- a/app/services/slash_commands/interpret_service.rb
+++ b/app/services/slash_commands/interpret_service.rb
@@ -18,11 +18,11 @@ module SlashCommands
 
       content, commands = extractor.extract_commands(content, opts)
 
-      commands.each do |name, *args|
+      commands.each do |name, args|
         definition = self.class.command_definitions_by_name[name.to_sym]
         next unless definition
 
-        definition.execute(self, opts, *args)
+        definition.execute(self, opts, args)
       end
 
       [content, @updates]
@@ -76,7 +76,6 @@ module SlashCommands
     command :assign do |assignee_param|
       user = extract_references(assignee_param, :user).first
       user ||= User.find_by(username: assignee_param)
-      user ||= User.find_by(name: assignee_param)
 
       @updates[:assignee_id] = user.id if user
     end
diff --git a/lib/gitlab/slash_commands/command_definition.rb b/lib/gitlab/slash_commands/command_definition.rb
index 641c92e77da..2ff8f4eddf0 100644
--- a/lib/gitlab/slash_commands/command_definition.rb
+++ b/lib/gitlab/slash_commands/command_definition.rb
@@ -6,11 +6,11 @@ module Gitlab
       def initialize(name, attributes = {})
         @name = name
 
-        @aliases          =  attributes[:aliases] || []
-        @description      =  attributes[:description] || ''
-        @params           =  attributes[:params] || []
-        @condition_block  =  attributes[:condition_block]
-        @action_block     =  attributes[:action_block]
+        @aliases         = attributes[:aliases] || []
+        @description     = attributes[:description] || ''
+        @params          = attributes[:params] || []
+        @condition_block = attributes[:condition_block]
+        @action_block    = attributes[:action_block]
       end
 
       def all_names
@@ -28,13 +28,13 @@ module Gitlab
         context.instance_exec(&condition_block)
       end
 
-      def execute(context, opts, *args)
+      def execute(context, opts, args)
         return if noop? || !available?(opts)
 
         block_arity = action_block.arity
-        return unless block_arity == -1 || block_arity == args.size
+        return unless (args.present? && block_arity == 1) || (args.blank? && block_arity <= 0)
 
-        context.instance_exec(*args, &action_block)
+        context.instance_exec(args, &action_block)
       end
 
       def to_h(opts)
diff --git a/lib/gitlab/slash_commands/extractor.rb b/lib/gitlab/slash_commands/extractor.rb
index 02c4c8c492e..c790b825347 100644
--- a/lib/gitlab/slash_commands/extractor.rb
+++ b/lib/gitlab/slash_commands/extractor.rb
@@ -50,15 +50,6 @@ module Gitlab
       end
 
       private
-
-      def command_names(opts)
-        command_definitions.flat_map do |command|
-          next if command.noop?
-
-          command.all_names
-        end.compact
-      end
-
       # Builds a regular expression to match known commands.
       # First match group captures the command name and
       # second match group captures its arguments.
@@ -117,6 +108,14 @@ module Gitlab
             )
         }mx
       end
+
+      def command_names(opts)
+        command_definitions.flat_map do |command|
+          next if command.noop?
+
+          command.all_names
+        end.compact
+      end
     end
   end
 end

From 9aa3edc61586fd79ce0760b7af0946ddfadaa65a Mon Sep 17 00:00:00 2001
From: Douwe Maan <douwe@selenight.nl>
Date: Wed, 17 Aug 2016 18:58:52 -0500
Subject: [PATCH 23/25] Remove unneeded aliases

---
 .../slash_commands/interpret_service.rb       |  35 +++--
 doc/workflow/slash_commands.md                |  40 +++---
 .../issues/user_uses_slash_commands_spec.rb   |   8 +-
 .../user_uses_slash_commands_spec.rb          |   4 +-
 .../gitlab/slash_commands/extractor_spec.rb   |  16 +--
 .../notes/slash_commands_service_spec.rb      |   8 +-
 .../slash_commands/interpret_service_spec.rb  | 123 ++++++++----------
 ..._service_slash_commands_shared_examples.rb |   4 +-
 8 files changed, 115 insertions(+), 123 deletions(-)

diff --git a/app/services/slash_commands/interpret_service.rb b/app/services/slash_commands/interpret_service.rb
index dc4a892b8b1..0d7838055fe 100644
--- a/app/services/slash_commands/interpret_service.rb
+++ b/app/services/slash_commands/interpret_service.rb
@@ -54,7 +54,7 @@ module SlashCommands
         issuable.closed? &&
         current_user.can?(:"update_#{issuable.to_ability_name}", issuable)
     end
-    command :reopen, :open do
+    command :reopen do
       @updates[:state_event] = 'reopen'
     end
 
@@ -86,7 +86,7 @@ module SlashCommands
         issuable.assignee_id? &&
         current_user.can?(:"admin_#{issuable.to_ability_name}", project)
     end
-    command :unassign, :remove_assignee do
+    command :unassign do
       @updates[:assignee_id] = nil
     end
 
@@ -109,7 +109,7 @@ module SlashCommands
         issuable.milestone_id? &&
         current_user.can?(:"admin_#{issuable.to_ability_name}", project)
     end
-    command :clear_milestone, :remove_milestone do
+    command :remove_milestone do
       @updates[:milestone_id] = nil
     end
 
@@ -119,33 +119,40 @@ module SlashCommands
       current_user.can?(:"admin_#{issuable.to_ability_name}", project) &&
         project.labels.any?
     end
-    command :label, :labels do |labels_param|
+    command :label do |labels_param|
       label_ids = find_label_ids(labels_param)
 
       @updates[:add_label_ids] = label_ids unless label_ids.empty?
     end
 
-    desc 'Remove label(s)'
+    desc 'Remove all or specific label(s)'
     params '~label1 ~"label 2"'
     condition do
       issuable.persisted? &&
         issuable.labels.any? &&
         current_user.can?(:"admin_#{issuable.to_ability_name}", project)
     end
-    command :unlabel, :remove_label, :remove_labels do |labels_param|
-      label_ids = find_label_ids(labels_param)
+    command :unlabel do |labels_param = nil|
+      if labels_param.present?
+        label_ids = find_label_ids(labels_param)
 
-      @updates[:remove_label_ids] = label_ids unless label_ids.empty?
+        @updates[:remove_label_ids] = label_ids unless label_ids.empty?
+      else
+        @updates[:label_ids] = []
+      end
     end
 
-    desc 'Remove all labels'
+    desc 'Replace all label(s)'
+    params '~label1 ~"label 2"'
     condition do
       issuable.persisted? &&
         issuable.labels.any? &&
         current_user.can?(:"admin_#{issuable.to_ability_name}", project)
     end
-    command :clear_labels, :clear_label do
-      @updates[:label_ids] = []
+    command :relabel do |labels_param|
+      label_ids = find_label_ids(labels_param)
+
+      @updates[:label_ids] = label_ids unless label_ids.empty?
     end
 
     desc 'Add a todo'
@@ -185,12 +192,12 @@ module SlashCommands
     end
 
     desc 'Set due date'
-    params '<in 2 days; this Friday; December 31st>'
+    params '<in 2 days | this Friday | December 31st>'
     condition do
       issuable.respond_to?(:due_date) &&
         current_user.can?(:"update_#{issuable.to_ability_name}", issuable)
     end
-    command :due, :due_date do |due_date_param|
+    command :due do |due_date_param|
       due_date = Chronic.parse(due_date_param).try(:to_date)
 
       @updates[:due_date] = due_date if due_date
@@ -203,7 +210,7 @@ module SlashCommands
         issuable.due_date? &&
         current_user.can?(:"update_#{issuable.to_ability_name}", issuable)
     end
-    command :clear_due_date do
+    command :remove_due_date do
       @updates[:due_date] = nil
     end
 
diff --git a/doc/workflow/slash_commands.md b/doc/workflow/slash_commands.md
index 75fec7bcdb9..91d69d4e77e 100644
--- a/doc/workflow/slash_commands.md
+++ b/doc/workflow/slash_commands.md
@@ -5,26 +5,26 @@ requests that are usually done by clicking buttons or dropdowns in GitLab's UI.
 You can enter these commands while creating a new issue or merge request, and
 in comments. Each command should be on a separate line in order to be properly
 detected and executed. The commands are removed from the issue, merge request or
-comment body before it is saved and will not be visible as such to anyone else.
+comment body before it is saved and will not be visible to anyone else.
 
-Here is a list of all of the available commands and descriptions about what they
+Below is a list of all of the available commands and descriptions about what they
 do.
 
-| Command                    | Aliases             | Action       |
-|:---------------------------|:--------------------|:-------------|
-| `/close`                   | None                | Close the issue or merge request |
-| `/reopen`                  | `/open`             | Reopen the issue or merge request |
-| `/title <New title>`       | None                | Change title |
-| `/assign @username`        | None                | Assign |
-| `/unassign`                | `/remove_assignee`  | Remove assignee |
-| `/milestone %milestone`    | None                | Set milestone |
-| `/clear_milestone`         | `/remove_milestone` | Remove milestone |
-| `/label ~foo ~"bar baz"`   | `/labels`           | Add label(s) |
-| `/unlabel ~foo ~"bar baz"` | `/remove_label`, `remove_labels` | Remove label(s) |
-| `/clear_labels`            | `/clear_label`      | Clear all labels |
-| `/todo`                    | None                | Add a todo |
-| `/done`                    | None                | Mark todo as done |
-| `/subscribe`               | None                | Subscribe |
-| `/unsubscribe`             | None                | Unsubscribe |
-| `/due <in 2 days; this Friday; December 31st>` | `/due_date` | Set due date |
-| `/clear_due_date`          | None                | Remove due date |
+| Command                    | Action       |
+|:---------------------------|:-------------|
+| `/close`                   | Close the issue or merge request |
+| `/reopen`                  | Reopen the issue or merge request |
+| `/title <New title>`       | Change title |
+| `/assign @username`        | Assign |
+| `/unassign`                | Remove assignee |
+| `/milestone %milestone`    | Set milestone |
+| `/remove_milestone`        | Remove milestone |
+| `/label ~foo ~"bar baz"`   | Add label(s) |
+| `/unlabel ~foo ~"bar baz"` | Remove all or specific label(s) |
+| `/relabel ~foo ~"bar baz"` | Replace all label(s) |
+| `/todo`                    | Add a todo |
+| `/done`                    | Mark todo as done |
+| `/subscribe`               | Subscribe |
+| `/unsubscribe`             | Unsubscribe |
+| `/due <in 2 days | this Friday | December 31st>` | Set due date |
+| `/remove_due_date`          | Remove due date |
diff --git a/spec/features/issues/user_uses_slash_commands_spec.rb b/spec/features/issues/user_uses_slash_commands_spec.rb
index 510f4254b54..2883e392694 100644
--- a/spec/features/issues/user_uses_slash_commands_spec.rb
+++ b/spec/features/issues/user_uses_slash_commands_spec.rb
@@ -22,11 +22,11 @@ feature 'Issues > User uses slash commands', feature: true, js: true do
 
       it 'does not create a note, and sets the due date accordingly' do
         page.within('.js-main-target-form') do
-          fill_in 'note[note]', with: "/due_date 2016-08-28"
+          fill_in 'note[note]', with: "/due 2016-08-28"
           click_button 'Comment'
         end
 
-        expect(page).not_to have_content '/due_date 2016-08-28'
+        expect(page).not_to have_content '/due 2016-08-28'
         expect(page).to have_content 'Your commands have been executed!'
 
         issue.reload
@@ -42,11 +42,11 @@ feature 'Issues > User uses slash commands', feature: true, js: true do
         expect(issue.due_date).to eq Date.new(2016, 8, 28)
 
         page.within('.js-main-target-form') do
-          fill_in 'note[note]', with: "/clear_due_date"
+          fill_in 'note[note]', with: "/remove_due_date"
           click_button 'Comment'
         end
 
-        expect(page).not_to have_content '/clear_due_date'
+        expect(page).not_to have_content '/remove_due_date'
         expect(page).to have_content 'Your commands have been executed!'
 
         issue.reload
diff --git a/spec/features/merge_requests/user_uses_slash_commands_spec.rb b/spec/features/merge_requests/user_uses_slash_commands_spec.rb
index 08c452c6e59..d9ef0d18074 100644
--- a/spec/features/merge_requests/user_uses_slash_commands_spec.rb
+++ b/spec/features/merge_requests/user_uses_slash_commands_spec.rb
@@ -22,11 +22,11 @@ feature 'Merge Requests > User uses slash commands', feature: true, js: true do
 
     it 'does not recognize the command nor create a note' do
       page.within('.js-main-target-form') do
-        fill_in 'note[note]', with: "/due_date 2016-08-28"
+        fill_in 'note[note]', with: "/due 2016-08-28"
         click_button 'Comment'
       end
 
-      expect(page).not_to have_content '/due_date 2016-08-28'
+      expect(page).not_to have_content '/due 2016-08-28'
     end
   end
 end
diff --git a/spec/lib/gitlab/slash_commands/extractor_spec.rb b/spec/lib/gitlab/slash_commands/extractor_spec.rb
index 09f909dcdd2..1e4954c4af8 100644
--- a/spec/lib/gitlab/slash_commands/extractor_spec.rb
+++ b/spec/lib/gitlab/slash_commands/extractor_spec.rb
@@ -18,7 +18,7 @@ describe Gitlab::SlashCommands::Extractor do
     it 'extracts command' do
       msg, commands = extractor.extract_commands(original_msg)
 
-      expect(commands).to eq [['open']]
+      expect(commands).to eq [['reopen']]
       expect(msg).to eq final_msg
     end
   end
@@ -45,31 +45,31 @@ describe Gitlab::SlashCommands::Extractor do
     describe 'command with no argument' do
       context 'at the start of content' do
         it_behaves_like 'command with no argument' do
-          let(:original_msg) { "/open\nworld" }
+          let(:original_msg) { "/reopen\nworld" }
           let(:final_msg) { "world" }
         end
       end
 
       context 'in the middle of content' do
         it_behaves_like 'command with no argument' do
-          let(:original_msg) { "hello\n/open\nworld" }
+          let(:original_msg) { "hello\n/reopen\nworld" }
           let(:final_msg) { "hello\nworld" }
         end
       end
 
       context 'in the middle of a line' do
         it 'does not extract command' do
-          msg = "hello\nworld /open"
+          msg = "hello\nworld /reopen"
           msg, commands = extractor.extract_commands(msg)
 
           expect(commands).to be_empty
-          expect(msg).to eq "hello\nworld /open"
+          expect(msg).to eq "hello\nworld /reopen"
         end
       end
 
       context 'at the end of content' do
         it_behaves_like 'command with no argument' do
-          let(:original_msg) { "hello\n/open" }
+          let(:original_msg) { "hello\n/reopen" }
           let(:final_msg) { "hello" }
         end
       end
@@ -170,10 +170,10 @@ describe Gitlab::SlashCommands::Extractor do
     end
 
     it 'extracts multiple commands' do
-      msg = %(hello\n/power @user.name %9.10 ~"bar baz.2" label\nworld\n/open)
+      msg = %(hello\n/power @user.name %9.10 ~"bar baz.2" label\nworld\n/reopen)
       msg, commands = extractor.extract_commands(msg)
 
-      expect(commands).to eq [['power', '@user.name %9.10 ~"bar baz.2" label'], ['open']]
+      expect(commands).to eq [['power', '@user.name %9.10 ~"bar baz.2" label'], ['reopen']]
       expect(msg).to eq "hello\nworld"
     end
 
diff --git a/spec/services/notes/slash_commands_service_spec.rb b/spec/services/notes/slash_commands_service_spec.rb
index 9a262fcf32f..4f231aab161 100644
--- a/spec/services/notes/slash_commands_service_spec.rb
+++ b/spec/services/notes/slash_commands_service_spec.rb
@@ -69,12 +69,12 @@ describe Notes::SlashCommandsService, services: true do
         end
       end
 
-      describe '/open' do
+      describe '/reopen' do
         before do
           note.noteable.close!
           expect(note.noteable).to be_closed
         end
-        let(:note_text) { '/open' }
+        let(:note_text) { '/reopen' }
 
         it 'opens the noteable, and leave no note' do
           content, command_params = service.extract_commands(note)
@@ -104,12 +104,12 @@ describe Notes::SlashCommandsService, services: true do
         end
       end
 
-      describe '/open' do
+      describe '/reopen' do
         before do
           note.noteable.close
           expect(note.noteable).to be_closed
         end
-        let(:note_text) { "HELLO\n/open\nWORLD" }
+        let(:note_text) { "HELLO\n/reopen\nWORLD" }
 
         it 'opens the noteable' do
           content, command_params = service.extract_commands(note)
diff --git a/spec/services/slash_commands/interpret_service_spec.rb b/spec/services/slash_commands/interpret_service_spec.rb
index c20aa90ddde..a616275e883 100644
--- a/spec/services/slash_commands/interpret_service_spec.rb
+++ b/spec/services/slash_commands/interpret_service_spec.rb
@@ -16,8 +16,8 @@ describe SlashCommands::InterpretService, services: true do
     let(:service) { described_class.new(project, user) }
     let(:merge_request) { create(:merge_request, source_project: project) }
 
-    shared_examples 'open command' do
-      it 'returns state_event: "open" if content contains /open' do
+    shared_examples 'reopen command' do
+      it 'returns state_event: "reopen" if content contains /reopen' do
         issuable.close!
         _, updates = service.execute(content, issuable)
 
@@ -26,7 +26,7 @@ describe SlashCommands::InterpretService, services: true do
     end
 
     shared_examples 'close command' do
-      it 'returns state_event: "close" if content contains /open' do
+      it 'returns state_event: "close" if content contains /close' do
         _, updates = service.execute(content, issuable)
 
         expect(updates).to eq(state_event: 'close')
@@ -67,8 +67,8 @@ describe SlashCommands::InterpretService, services: true do
       end
     end
 
-    shared_examples 'clear_milestone command' do
-      it 'populates milestone_id: nil if content contains /clear_milestone' do
+    shared_examples 'remove_milestone command' do
+      it 'populates milestone_id: nil if content contains /remove_milestone' do
         issuable.update(milestone_id: milestone.id)
         _, updates = service.execute(content, issuable)
 
@@ -95,8 +95,8 @@ describe SlashCommands::InterpretService, services: true do
       end
     end
 
-    shared_examples 'clear_labels command' do
-      it 'populates label_ids: [] if content contains /clear_labels' do
+    shared_examples 'unlabel command with no argument' do
+      it 'populates label_ids: [] if content contains /unlabel with no arguments' do
         issuable.update(label_ids: [inprogress.id]) # populate the label
         _, updates = service.execute(content, issuable)
 
@@ -104,6 +104,16 @@ describe SlashCommands::InterpretService, services: true do
       end
     end
 
+    shared_examples 'relabel command' do
+      it 'populates label_ids: [] if content contains /relabel' do
+        issuable.update(label_ids: [bug.id]) # populate the label
+        inprogress # populate the label
+        _, updates = service.execute(content, issuable)
+
+        expect(updates).to eq(label_ids: [inprogress.id])
+      end
+    end
+
     shared_examples 'todo command' do
       it 'populates todo_event: "add" if content contains /todo' do
         _, updates = service.execute(content, issuable)
@@ -138,16 +148,16 @@ describe SlashCommands::InterpretService, services: true do
       end
     end
 
-    shared_examples 'due_date command' do
-      it 'populates due_date: Date.new(2016, 8, 28) if content contains /due_date 2016-08-28' do
+    shared_examples 'due command' do
+      it 'populates due_date: Date.new(2016, 8, 28) if content contains /due 2016-08-28' do
         _, updates = service.execute(content, issuable)
 
         expect(updates).to eq(due_date: defined?(expected_date) ? expected_date : Date.new(2016, 8, 28))
       end
     end
 
-    shared_examples 'clear_due_date command' do
-      it 'populates due_date: nil if content contains /clear_due_date' do
+    shared_examples 'remove_due_date command' do
+      it 'populates due_date: nil if content contains /remove_due_date' do
         issuable.update(due_date: Date.today)
         _, updates = service.execute(content, issuable)
 
@@ -163,21 +173,16 @@ describe SlashCommands::InterpretService, services: true do
       end
     end
 
-    it_behaves_like 'open command' do
-      let(:content) { '/open' }
-      let(:issuable) { issue }
-    end
-
-    it_behaves_like 'open command' do
-      let(:content) { '/open' }
-      let(:issuable) { merge_request }
-    end
-
-    it_behaves_like 'open command' do
+    it_behaves_like 'reopen command' do
       let(:content) { '/reopen' }
       let(:issuable) { issue }
     end
 
+    it_behaves_like 'reopen command' do
+      let(:content) { '/reopen' }
+      let(:issuable) { merge_request }
+    end
+
     it_behaves_like 'close command' do
       let(:content) { '/close' }
       let(:issuable) { issue }
@@ -233,11 +238,6 @@ describe SlashCommands::InterpretService, services: true do
       let(:issuable) { merge_request }
     end
 
-    it_behaves_like 'unassign command' do
-      let(:content) { '/remove_assignee' }
-      let(:issuable) { issue }
-    end
-
     it_behaves_like 'milestone command' do
       let(:content) { "/milestone %#{milestone.title}" }
       let(:issuable) { issue }
@@ -248,21 +248,16 @@ describe SlashCommands::InterpretService, services: true do
       let(:issuable) { merge_request }
     end
 
-    it_behaves_like 'clear_milestone command' do
-      let(:content) { '/clear_milestone' }
-      let(:issuable) { issue }
-    end
-
-    it_behaves_like 'clear_milestone command' do
-      let(:content) { '/clear_milestone' }
-      let(:issuable) { merge_request }
-    end
-
-    it_behaves_like 'clear_milestone command' do
+    it_behaves_like 'remove_milestone command' do
       let(:content) { '/remove_milestone' }
       let(:issuable) { issue }
     end
 
+    it_behaves_like 'remove_milestone command' do
+      let(:content) { '/remove_milestone' }
+      let(:issuable) { merge_request }
+    end
+
     it_behaves_like 'label command' do
       let(:content) { %(/label ~"#{inprogress.title}" ~#{bug.title} ~unknown) }
       let(:issuable) { issue }
@@ -273,11 +268,6 @@ describe SlashCommands::InterpretService, services: true do
       let(:issuable) { merge_request }
     end
 
-    it_behaves_like 'label command' do
-      let(:content) { %(/labels ~"#{inprogress.title}" ~#{bug.title} ~unknown) }
-      let(:issuable) { issue }
-    end
-
     it_behaves_like 'unlabel command' do
       let(:content) { %(/unlabel ~"#{inprogress.title}") }
       let(:issuable) { issue }
@@ -288,31 +278,26 @@ describe SlashCommands::InterpretService, services: true do
       let(:issuable) { merge_request }
     end
 
-    it_behaves_like 'unlabel command' do
-      let(:content) { %(/remove_labels ~"#{inprogress.title}") }
+    it_behaves_like 'unlabel command with no argument' do
+      let(:content) { %(/unlabel) }
       let(:issuable) { issue }
     end
 
-    it_behaves_like 'unlabel command' do
-      let(:content) { %(/remove_label ~"#{inprogress.title}") }
-      let(:issuable) { issue }
-    end
-
-    it_behaves_like 'clear_labels command' do
-      let(:content) { '/clear_labels' }
-      let(:issuable) { issue }
-    end
-
-    it_behaves_like 'clear_labels command' do
-      let(:content) { '/clear_labels' }
+    it_behaves_like 'unlabel command with no argument' do
+      let(:content) { %(/unlabel) }
       let(:issuable) { merge_request }
     end
 
-    it_behaves_like 'clear_labels command' do
-      let(:content) { '/clear_label' }
+    it_behaves_like 'relabel command' do
+      let(:content) { %(/relabel ~"#{inprogress.title}") }
       let(:issuable) { issue }
     end
 
+    it_behaves_like 'relabel command' do
+      let(:content) { %(/relabel ~"#{inprogress.title}") }
+      let(:issuable) { merge_request }
+    end
+
     it_behaves_like 'todo command' do
       let(:content) { '/todo' }
       let(:issuable) { issue }
@@ -353,46 +338,46 @@ describe SlashCommands::InterpretService, services: true do
       let(:issuable) { merge_request }
     end
 
-    it_behaves_like 'due_date command' do
-      let(:content) { '/due_date 2016-08-28' }
+    it_behaves_like 'due command' do
+      let(:content) { '/due 2016-08-28' }
       let(:issuable) { issue }
     end
 
-    it_behaves_like 'due_date command' do
+    it_behaves_like 'due command' do
       let(:content) { '/due tomorrow' }
       let(:issuable) { issue }
       let(:expected_date) { Date.tomorrow }
     end
 
-    it_behaves_like 'due_date command' do
+    it_behaves_like 'due command' do
       let(:content) { '/due 5 days from now' }
       let(:issuable) { issue }
       let(:expected_date) { 5.days.from_now.to_date }
     end
 
-    it_behaves_like 'due_date command' do
+    it_behaves_like 'due command' do
       let(:content) { '/due in 2 days' }
       let(:issuable) { issue }
       let(:expected_date) { 2.days.from_now.to_date }
     end
 
     it_behaves_like 'empty command' do
-      let(:content) { '/due_date foo bar' }
+      let(:content) { '/due foo bar' }
       let(:issuable) { issue }
     end
 
     it_behaves_like 'empty command' do
-      let(:content) { '/due_date 2016-08-28' }
+      let(:content) { '/due 2016-08-28' }
       let(:issuable) { merge_request }
     end
 
-    it_behaves_like 'clear_due_date command' do
-      let(:content) { '/clear_due_date' }
+    it_behaves_like 'remove_due_date command' do
+      let(:content) { '/remove_due_date' }
       let(:issuable) { issue }
     end
 
     it_behaves_like 'empty command' do
-      let(:content) { '/clear_due_date' }
+      let(:content) { '/remove_due_date' }
       let(:issuable) { merge_request }
     end
   end
diff --git a/spec/support/issuable_create_service_slash_commands_shared_examples.rb b/spec/support/issuable_create_service_slash_commands_shared_examples.rb
index bd0201c866f..5f9645ed44f 100644
--- a/spec/support/issuable_create_service_slash_commands_shared_examples.rb
+++ b/spec/support/issuable_create_service_slash_commands_shared_examples.rb
@@ -14,7 +14,7 @@ shared_examples 'new issuable record that supports slash commands' do
   context 'with labels in command only' do
     let(:example_params) do
       {
-        description: "/label ~#{labels.first.name} ~#{labels.second.name}\n/remove_label ~#{labels.third.name}"
+        description: "/label ~#{labels.first.name} ~#{labels.second.name}\n/unlabel ~#{labels.third.name}"
       }
     end
 
@@ -28,7 +28,7 @@ shared_examples 'new issuable record that supports slash commands' do
     let(:example_params) do
       {
         label_ids: [labels.second.id],
-        description: "/label ~#{labels.first.name}\n/remove_label ~#{labels.third.name}"
+        description: "/label ~#{labels.first.name}\n/unlabel ~#{labels.third.name}"
       }
     end
 

From 6f2f2a6baae128cd4f8111d91bdcfb7b76e39b97 Mon Sep 17 00:00:00 2001
From: Douwe Maan <douwe@selenight.nl>
Date: Thu, 18 Aug 2016 14:19:13 -0500
Subject: [PATCH 24/25] Fix behavior of label_ids and add/remove_label_ids

---
 app/services/issuable_base_service.rb | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/app/services/issuable_base_service.rb b/app/services/issuable_base_service.rb
index 57286f255f4..3100bd58818 100644
--- a/app/services/issuable_base_service.rb
+++ b/app/services/issuable_base_service.rb
@@ -80,18 +80,19 @@ class IssuableBaseService < BaseService
     params[key] = project.labels.where(id: params[key]).pluck(:id)
   end
 
-  def process_label_ids(attributes, existing_label_ids: [])
+  def process_label_ids(attributes, existing_label_ids: nil)
     label_ids = attributes.delete(:label_ids)
     add_label_ids = attributes.delete(:add_label_ids)
     remove_label_ids = attributes.delete(:remove_label_ids)
 
-    new_label_ids = existing_label_ids
+    new_label_ids = existing_label_ids || label_ids || []
 
-    override_existing = new_label_ids.empty? || (add_label_ids.blank? && remove_label_ids.blank?)
-    new_label_ids = label_ids if label_ids && override_existing
-
-    new_label_ids |= add_label_ids if add_label_ids
-    new_label_ids -= remove_label_ids if remove_label_ids
+    if add_label_ids.blank? && remove_label_ids.blank?
+      new_label_ids = label_ids if label_ids
+    else
+      new_label_ids |= add_label_ids if add_label_ids
+      new_label_ids -= remove_label_ids if remove_label_ids
+    end
 
     new_label_ids
   end

From 2703330a19e813351e9c33241a59d6b7f54741df Mon Sep 17 00:00:00 2001
From: Douwe Maan <douwe@selenight.nl>
Date: Thu, 18 Aug 2016 14:21:52 -0500
Subject: [PATCH 25/25] Fix behavior around commands with optional arguments

---
 .../slash_commands/interpret_service.rb       |  4 +-
 .../slash_commands/command_definition.rb      | 11 +--
 lib/gitlab/slash_commands/extractor.rb        | 13 ++--
 .../slash_commands/command_definition_spec.rb | 72 +++++++++++++------
 spec/lib/gitlab/slash_commands/dsl_spec.rb    | 13 +---
 5 files changed, 67 insertions(+), 46 deletions(-)

diff --git a/app/services/slash_commands/interpret_service.rb b/app/services/slash_commands/interpret_service.rb
index 0d7838055fe..9ac1124abc1 100644
--- a/app/services/slash_commands/interpret_service.rb
+++ b/app/services/slash_commands/interpret_service.rb
@@ -18,11 +18,11 @@ module SlashCommands
 
       content, commands = extractor.extract_commands(content, opts)
 
-      commands.each do |name, args|
+      commands.each do |name, arg|
         definition = self.class.command_definitions_by_name[name.to_sym]
         next unless definition
 
-        definition.execute(self, opts, args)
+        definition.execute(self, opts, arg)
       end
 
       [content, @updates]
diff --git a/lib/gitlab/slash_commands/command_definition.rb b/lib/gitlab/slash_commands/command_definition.rb
index 2ff8f4eddf0..60d35be2599 100644
--- a/lib/gitlab/slash_commands/command_definition.rb
+++ b/lib/gitlab/slash_commands/command_definition.rb
@@ -28,13 +28,14 @@ module Gitlab
         context.instance_exec(&condition_block)
       end
 
-      def execute(context, opts, args)
+      def execute(context, opts, arg)
         return if noop? || !available?(opts)
 
-        block_arity = action_block.arity
-        return unless (args.present? && block_arity == 1) || (args.blank? && block_arity <= 0)
-
-        context.instance_exec(args, &action_block)
+        if arg.present?
+          context.instance_exec(arg, &action_block)
+        elsif action_block.arity == 0
+          context.instance_exec(&action_block)
+        end
       end
 
       def to_h(opts)
diff --git a/lib/gitlab/slash_commands/extractor.rb b/lib/gitlab/slash_commands/extractor.rb
index c790b825347..a672e5e4855 100644
--- a/lib/gitlab/slash_commands/extractor.rb
+++ b/lib/gitlab/slash_commands/extractor.rb
@@ -39,7 +39,7 @@ module Gitlab
         content.delete!("\r")
         content.gsub!(commands_regex(opts)) do
           if $~[:cmd]
-            commands << [$~[:cmd], $~[:args]].reject(&:blank?)
+            commands << [$~[:cmd], $~[:arg]].reject(&:blank?)
             ''
           else
             $~[0]
@@ -50,13 +50,14 @@ module Gitlab
       end
 
       private
+
       # Builds a regular expression to match known commands.
       # First match group captures the command name and
       # second match group captures its arguments.
       #
       # It looks something like:
       #
-      #   /^\/(?<cmd>close|reopen|...)(?:( |$))(?<args>[^\/\n]*)(?:\n|$)/
+      #   /^\/(?<cmd>close|reopen|...)(?:( |$))(?<arg>[^\/\n]*)(?:\n|$)/
       def commands_regex(opts)
         names = command_names(opts).map(&:to_s)
 
@@ -64,7 +65,7 @@ module Gitlab
             (?<code>
               # Code blocks:
               # ```
-              # Anything, including `/cmd args` which are ignored by this filter
+              # Anything, including `/cmd arg` which are ignored by this filter
               # ```
 
               ^```
@@ -75,7 +76,7 @@ module Gitlab
             (?<html>
               # HTML block:
               # <tag>
-              # Anything, including `/cmd args` which are ignored by this filter
+              # Anything, including `/cmd arg` which are ignored by this filter
               # </tag>
 
               ^<[^>]+?>\n
@@ -86,7 +87,7 @@ module Gitlab
             (?<html>
               # Quote block:
               # >>>
-              # Anything, including `/cmd args` which are ignored by this filter
+              # Anything, including `/cmd arg` which are ignored by this filter
               # >>>
 
               ^>>>
@@ -102,7 +103,7 @@ module Gitlab
               (?<cmd>#{Regexp.union(names)})
               (?:
                 [ ]
-                (?<args>[^\/\n]*)
+                (?<arg>[^\/\n]*)
               )?
               (?:\n|$)
             )
diff --git a/spec/lib/gitlab/slash_commands/command_definition_spec.rb b/spec/lib/gitlab/slash_commands/command_definition_spec.rb
index 2a75fab24b0..c9c2f314e57 100644
--- a/spec/lib/gitlab/slash_commands/command_definition_spec.rb
+++ b/spec/lib/gitlab/slash_commands/command_definition_spec.rb
@@ -24,7 +24,7 @@ describe Gitlab::SlashCommands::CommandDefinition do
   describe "#noop?" do
     context "when the command has an action block" do
       before do
-        subject.action_block = -> { }
+        subject.action_block = proc { }
       end
 
       it "returns false" do
@@ -44,7 +44,7 @@ describe Gitlab::SlashCommands::CommandDefinition do
 
     context "when the command has a condition block" do
       before do
-        subject.condition_block = -> { go }
+        subject.condition_block = proc { go }
       end
 
       context "when the condition block returns true" do
@@ -78,7 +78,7 @@ describe Gitlab::SlashCommands::CommandDefinition do
       it "doesn't execute the command" do
         expect(context).not_to receive(:instance_exec)
 
-        subject.execute(context, {})
+        subject.execute(context, {}, nil)
 
         expect(context.run).to be false
       end
@@ -86,52 +86,82 @@ describe Gitlab::SlashCommands::CommandDefinition do
 
     context "when the command is not a noop" do
       before do
-        subject.action_block = -> { self.run = true }
+        subject.action_block = proc { self.run = true }
       end
 
       context "when the command is not available" do
         before do
-          subject.condition_block = -> { false }
+          subject.condition_block = proc { false }
         end
 
         it "doesn't execute the command" do
-          subject.execute(context, {})
+          subject.execute(context, {}, nil)
 
           expect(context.run).to be false
         end
       end
 
       context "when the command is available" do
-        context "when the command has an exact number of arguments" do
+        context "when the commnd has no arguments" do
           before do
-            subject.action_block = ->(arg) { self.run = arg }
+            subject.action_block = proc { self.run = true }
           end
 
-          context "when the command is provided a wrong number of arguments" do
-            it "doesn't execute the command" do
-              subject.execute(context, {}, true, true)
-
-              expect(context.run).to be false
-            end
-          end
-
-          context "when the command is provided the right number of arguments" do
+          context "when the command is provided an argument" do
             it "executes the command" do
               subject.execute(context, {}, true)
 
               expect(context.run).to be true
             end
           end
+
+          context "when the command is not provided an argument" do
+            it "executes the command" do
+              subject.execute(context, {}, nil)
+
+              expect(context.run).to be true
+            end
+          end
         end
 
-        context "when the command has a variable number of arguments" do
+        context "when the command has 1 required argument" do
           before do
-            subject.action_block = ->(*args) { self.run = args.first }
+            subject.action_block = ->(arg) { self.run = arg }
           end
 
-          context "when the command is provided any number of arguments" do
+          context "when the command is provided an argument" do
             it "executes the command" do
-              subject.execute(context, {}, true, true)
+              subject.execute(context, {}, true)
+
+              expect(context.run).to be true
+            end
+          end
+
+          context "when the command is not provided an argument" do
+            it "doesn't execute the command" do
+              subject.execute(context, {}, nil)
+
+              expect(context.run).to be false
+            end
+          end
+        end
+
+        context "when the command has 1 optional argument" do
+          before do
+            subject.action_block = proc { |arg = nil| self.run = arg || true }
+          end
+
+          context "when the command is provided an argument" do
+            it "executes the command" do
+              subject.execute(context, {}, true)
+
+              expect(context.run).to be true
+            end
+          end
+
+          context "when the command is not provided an argument" do
+            it "executes the command" do
+              subject.execute(context, {}, nil)
 
               expect(context.run).to be true
             end
diff --git a/spec/lib/gitlab/slash_commands/dsl_spec.rb b/spec/lib/gitlab/slash_commands/dsl_spec.rb
index 9ec00c25787..26217a0e3b2 100644
--- a/spec/lib/gitlab/slash_commands/dsl_spec.rb
+++ b/spec/lib/gitlab/slash_commands/dsl_spec.rb
@@ -31,16 +31,12 @@ describe Gitlab::SlashCommands::Dsl do
       command :cond_action do |arg|
         arg
       end
-
-      command :wildcard do |*args|
-        args
-      end
     end
   end
 
   describe '.command_definitions' do
     it 'returns an array with commands definitions' do
-      no_args_def, one_arg_def, two_args_def, cc_def, cond_action_def, wildcard_def = DummyClass.command_definitions
+      no_args_def, one_arg_def, two_args_def, cc_def, cond_action_def = DummyClass.command_definitions
 
       expect(no_args_def.name).to eq(:no_args)
       expect(no_args_def.aliases).to eq([:none])
@@ -76,13 +72,6 @@ describe Gitlab::SlashCommands::Dsl do
       expect(cond_action_def.params).to eq([])
       expect(cond_action_def.condition_block).to be_a_kind_of(Proc)
       expect(cond_action_def.action_block).to be_a_kind_of(Proc)
-
-      expect(wildcard_def.name).to eq(:wildcard)
-      expect(wildcard_def.aliases).to eq([])
-      expect(wildcard_def.description).to eq('')
-      expect(wildcard_def.params).to eq([])
-      expect(wildcard_def.condition_block).to be_nil
-      expect(wildcard_def.action_block).to be_a_kind_of(Proc)
     end
   end
 end