Remove EE-specific code from Mentionable

app/models/concerns/mentionable.rb

@@ -61,7 +61,7 @@ module Mentionable
         cache_key: [self, attr],
         author: author,
         skip_project_check: skip_project_check?
-      )
+      ).merge(mentionable_params)
 
       extractor.analyze(text, options)
     end
@@ -86,12 +86,11 @@ module Mentionable
     return [] unless matches_cross_reference_regex?
 
     refs = all_references(current_user)
-    refs = (refs.issues + refs.merge_requests + refs.commits)
 
     # We're using this method instead of Array diffing because that requires
     # both of the object's `hash` values to be the same, which may not be the
     # case for otherwise identical Commit objects.
-    refs.reject { |ref| ref == local_reference }
+    extracted_mentionables(refs).reject { |ref| ref == local_reference }
   end
 
   # Uses regex to quickly determine if mentionables might be referenced
@@ -134,6 +133,10 @@ module Mentionable
 
   private
 
+  def extracted_mentionables(refs)
+    refs.issues + refs.merge_requests + refs.commits
+  end
+
   # Returns a Hash of changed mentionable fields
   #
   # Preference is given to the `changes` Hash, but falls back to
@@ -161,4 +164,8 @@ module Mentionable
   def skip_project_check?
     false
   end
+
+  def mentionable_params
+    {}
+  end
 end

app/models/concerns/mentionable/reference_regexes.rb

@@ -5,13 +5,19 @@ module Mentionable
     def self.reference_pattern(link_patterns, issue_pattern)
       Regexp.union(link_patterns,
                    issue_pattern,
-                   Commit.reference_pattern,
-                   MergeRequest.reference_pattern)
+                   *other_patterns)
+    end
+
+    def self.other_patterns
+      [
+        Commit.reference_pattern,
+        MergeRequest.reference_pattern
+      ]
     end
 
     DEFAULT_PATTERN = begin
       issue_pattern = Issue.reference_pattern
-      link_patterns = Regexp.union([Issue, Commit, MergeRequest].map(&:link_reference_pattern))
+      link_patterns = Regexp.union([Issue, Commit, MergeRequest, Epic].map(&:link_reference_pattern).compact)
       reference_pattern(link_patterns, issue_pattern)
     end
 

app/models/epic.rb

@@ -3,6 +3,10 @@
 # Placeholder class for model that is implemented in EE
 # It reserves '&' as a reference prefix, but the table does not exists in CE
 class Epic < ActiveRecord::Base
+  def self.link_reference_pattern
+    nil
+  end
+
   def self.reference_prefix
     '&'
   end