Move common logic to reference group/project label to Label#to_reference

app/models/group_label.rb

@@ -3,32 +3,7 @@ class GroupLabel < Label
 
   validates :group, presence: true
 
-  ##
-  # Returns the String necessary to reference this GroupLabel in Markdown
-  #
-  # format - Symbol format to use (default: :id, optional: :name)
-  #
-  # Examples:
-  #
-  #   GroupLabel.first.to_reference                # => "~1"
-  #   GroupLabel.first.to_reference(format: :name) # => "~\"bug\""
-  #
-  # Returns a String
-  #
   def to_reference(source_project = nil, target_project = nil, format: :id)
-    format_reference = label_format_reference(format)
-    reference = "#{self.class.reference_prefix}#{format_reference}"
-
-    if cross_project_reference?(source_project, target_project)
-      source_project.to_reference + reference
-    else
-      reference
-    end
-  end
-
-  private
-
-  def cross_project_reference?(source_project, target_project)
-    source_project && target_project && source_project != target_project
+    super(source_project, target_project, format: format)
   end
 end

app/models/label.rb

@@ -97,8 +97,36 @@ class Label < ActiveRecord::Base
     write_attribute(:title, sanitize_title(value)) if value.present?
   end
 
+  ##
+  # Returns the String necessary to reference this Label in Markdown
+  #
+  # format - Symbol format to use (default: :id, optional: :name)
+  #
+  # Examples:
+  #
+  #   Label.first.to_reference                     # => "~1"
+  #   Label.first.to_reference(format: :name)      # => "~\"bug\""
+  #   Label.first.to_reference(project1, project2) # => "gitlab-org/gitlab-ce~1"
+  #
+  # Returns a String
+  #
+  def to_reference(source_project = nil, target_project = nil, format: :id)
+    format_reference = label_format_reference(format)
+    reference = "#{self.class.reference_prefix}#{format_reference}"
+
+    if cross_project_reference?(source_project, target_project)
+      source_project.to_reference + reference
+    else
+      reference
+    end
+  end
+
   private
 
+  def cross_project_reference?(source_project, target_project)
+    source_project && target_project && source_project != target_project
+  end
+
   def issues_count(user, params = {})
     IssuesFinder.new(user, { label_name: title, scope: 'all' }.merge(params))
                 .execute

app/models/project_label.rb

@@ -7,28 +7,8 @@ class ProjectLabel < Label
 
   delegate :group, to: :project, allow_nil: true
 
-  ##
-  # Returns the String necessary to reference this ProjectLabel in Markdown
-  #
-  # format - Symbol format to use (default: :id, optional: :name)
-  #
-  # Examples:
-  #
-  #   ProjectLabel.first.to_reference                # => "~1"
-  #   ProjectLabel.first.to_reference(format: :name) # => "~\"bug\""
-  #   ProjectLabel.first.to_reference(project)       # => "gitlab-org/gitlab-ce~1"
-  #
-  # Returns a String
-  #
-  def to_reference(from_project = nil, format: :id)
-    format_reference = label_format_reference(format)
-    reference = "#{self.class.reference_prefix}#{format_reference}"
-
-    if cross_project_reference?(from_project)
-      project.to_reference + reference
-    else
-      reference
-    end
+  def to_reference(target_project = nil, format: :id)
+    super(project, target_project, format: format)
   end
 
   private