rename table subscribe; make it polymorfic

app/controllers/projects/issues_controller.rb

@@ -100,7 +100,7 @@ class Projects::IssuesController < Projects::ApplicationController
   def set_subscription
     subscribed = params[:subscription] == "Subscribe"
 
-    sub = @issue.subscribes.find_or_create_by(user_id: current_user.id)
+    sub = @issue.subscriptions.find_or_create_by(user_id: current_user.id)
     sub.update(subscribed: subscribed)
     
     render nothing: true

app/controllers/projects/merge_requests_controller.rb

@@ -177,7 +177,7 @@ class Projects::MergeRequestsController < Projects::ApplicationController
   def set_subscription
     subscribed = params[:subscription] == "Subscribe"
 
-    sub = @merge_request.subscribes.find_or_create_by(user_id: current_user.id)
+    sub = @merge_request.subscriptions.find_or_create_by(user_id: current_user.id)
     sub.update(subscribed: subscribed)
     
     render nothing: true

app/models/concerns/issuable.rb

@@ -15,7 +15,7 @@ module Issuable
     has_many :notes, as: :noteable, dependent: :destroy
     has_many :label_links, as: :target, dependent: :destroy
     has_many :labels, through: :label_links
-    has_many :subscribes, dependent: :destroy
+    has_many :subscriptions, dependent: :destroy, as: :subscribable
 
     validates :author, presence: true
     validates :title, presence: true, length: { within: 0..255 }
@@ -133,10 +133,11 @@ module Issuable
     users.concat(mentions.reduce([], :|)).uniq
   end
 
-  def subscribe_status(user)
-    subscribe = subscribes.find_by_user_id(user.id)
-    if subscribe
-      return subscribe.subscribed
+  def subscription_status(user)
+    subscription = subscriptions.find_by_user_id(user.id)
+
+    if subscription
+      return subscription.subscribed
     end
 
     participants.include?(user)

app/models/subscribe.rb

@@ -1,6 +0,0 @@
-class Subscribe < ActiveRecord::Base
-  belongs_to :user
-
-  validates :issue_id, uniqueness: { scope: :user_id, allow_nil: true }
-  validates :merge_request_id, uniqueness: { scope: :user_id, allow_nil: true }
-end

app/models/subscription.rb

@@ -0,0 +1,7 @@
+class Subscription < ActiveRecord::Base
+  belongs_to :subscribable, polymorphic: true
+
+  validates :user_id, 
+            uniqueness: { scope: [:subscribable_id, :subscribable_type]},
+            presence: true
+end

app/services/notification_service.rb

@@ -316,8 +316,8 @@ class NotificationService
 
   def reject_unsubscribed_users(recipients, target)
     recipients.reject do |user|
-      subscribe = target.subscribes.find_by_user_id(user.id)
-      subscribe && !subscribe.subscribed
+      subscription = target.subscriptions.find_by_user_id(user.id)
+      subscription && !subscription.subscribed
     end
   end
 
@@ -375,9 +375,9 @@ class NotificationService
   end
 
   def add_subscribed_users(recipients, target)
-    subscribes = target.subscribes
-    if subscribes.any?
-      recipients.merge(subscribes.where("subscribed is true").map(&:user))
+    subscriptions = target.subscriptions
+    if subscriptions.any?
+      recipients.merge(subscriptions.where("subscribed is true").map(&:user))
     else
       recipients
     end

app/views/projects/issues/_issue_context.html.haml

@@ -33,8 +33,8 @@
         Subscription:
         %i.fa.fa-spinner.fa-spin.hidden.subscription
         %span.sub_status
-          = @issue.subscribe_status(current_user) ? "subscribed" : "unsubscribed"
-    - subscribe_action = @issue.subscribe_status(current_user) ? "Unsubscribe" : "Subscribe"
+          = @issue.subscription_status(current_user) ? "subscribed" : "unsubscribed"
+    - subscribe_action = @issue.subscription_status(current_user) ? "Unsubscribe" : "Subscribe"
     %input.btn.subscribe-button{:type => "button", :value => subscribe_action}
 
 :coffeescript

app/views/projects/merge_requests/show/_context.html.haml

@@ -35,8 +35,8 @@
         Subscription:
         %i.fa.fa-spinner.fa-spin.hidden.subscription
         %span.sub_status
-          = @merge_request.subscribe_status(current_user) ? "subscribed" : "unsubscribed"
-    - subscribe_action = @merge_request.subscribe_status(current_user) ? "Unsubscribe" : "Subscribe"
+          = @merge_request.subscription_status(current_user) ? "subscribed" : "unsubscribed"
+    - subscribe_action = @merge_request.subscription_status(current_user) ? "Unsubscribe" : "Subscribe"
     %input.btn.subscribe-button{:type => "button", :value => subscribe_action}
 
 :coffeescript

db/migrate/20150313012111_create_subscribes_table.rb

@@ -1,16 +0,0 @@
-class CreateSubscribesTable < ActiveRecord::Migration
-  def change
-    create_table :subscribes do |t|
-      t.integer :user_id
-      t.integer :merge_request_id
-      t.integer :issue_id
-      t.boolean :subscribed
-      
-      t.timestamps
-    end
-
-    add_index :subscribes, :user_id
-    add_index :subscribes, :issue_id
-    add_index :subscribes, :merge_request_id
-  end
-end

db/migrate/20150313012111_create_subscriptions_table.rb

@@ -0,0 +1,13 @@
+class CreateSubscriptionsTable < ActiveRecord::Migration
+  def change
+    create_table :subscriptions do |t|
+      t.integer :user_id
+      t.references :subscribable, polymorphic: true
+      t.boolean :subscribed
+      
+      t.timestamps
+    end
+
+    add_index :subscriptions, [:subscribable_id, :subscribable_type, :user_id], unique: true, name: 'subscriptions_user_id_and_ref_fields'
+  end
+end

db/schema.rb

@@ -397,18 +397,16 @@ ActiveRecord::Schema.define(version: 20150313012111) do
   add_index "snippets", ["project_id"], name: "index_snippets_on_project_id", using: :btree
   add_index "snippets", ["visibility_level"], name: "index_snippets_on_visibility_level", using: :btree
 
-  create_table "subscribes", force: true do |t|
+  create_table "subscriptions", force: true do |t|
     t.integer  "user_id"
-    t.integer  "merge_request_id"
-    t.integer  "issue_id"
+    t.integer  "subscribable_id"
+    t.string   "subscribable_type"
     t.boolean  "subscribed"
     t.datetime "created_at"
     t.datetime "updated_at"
   end
 
-  add_index "subscribes", ["issue_id"], name: "index_subscribes_on_issue_id", using: :btree
-  add_index "subscribes", ["merge_request_id"], name: "index_subscribes_on_merge_request_id", using: :btree
-  add_index "subscribes", ["user_id"], name: "index_subscribes_on_user_id", using: :btree
+  add_index "subscriptions", ["subscribable_id", "subscribable_type", "user_id"], name: "subscriptions_user_id_and_ref_fields", unique: true, using: :btree
 
   create_table "taggings", force: true do |t|
     t.integer  "tag_id"