Move checking of recepients to a service.

app/controllers/projects_controller.rb

@@ -124,18 +124,12 @@ class ProjectsController < ApplicationController
   def autocomplete_sources
     note_type = params['type']
     note_id = params['type_id']
-    participating = if note_type && note_id
-                      participants_in(note_type, note_id)
-                    else
-                      []
-                    end
-    team_members = sorted(@project.team.members)
-    participants = [{ username: "all", name: "Project and Group Members" }] + team_members + participating
+    participants = ::Projects::ParticipantsService.new(@project).execute(note_type, note_id)
     @suggestions = {
       emojis: Emoji.names.map { |e| { name: e, path: view_context.image_url("emoji/#{e}.png") } },
       issues: @project.issues.select([:iid, :title, :description]),
       mergerequests: @project.merge_requests.select([:iid, :title, :description]),
-      members: participants.uniq
+      members: participants
     }
 
     respond_to do |format|
@@ -191,25 +185,4 @@ class ProjectsController < ApplicationController
   def user_layout
     current_user ? "projects" : "public_projects"
   end
-
-  def participants_in(type, id)
-    users = case type
-            when "Issue"
-              issue = @project.issues.find_by_iid(id)
-              issue ? issue.participants : []
-            when "MergeRequest"
-              merge_request = @project.merge_requests.find_by_iid(id)
-              merge_request ? merge_request.participants : []
-            when "Commit"
-              author_ids = Note.for_commit_id(id).pluck(:author_id).uniq
-              User.where(id: author_ids)
-            else
-              []
-            end
-    sorted(users)
-  end
-
-  def sorted(users)
-    users.uniq.to_a.compact.sort_by(&:username).map { |user| { username: user.username, name: user.name } }
-  end
 end

app/models/concerns/mentionable.rb

@@ -55,7 +55,7 @@ module Mentionable
         if has_project
           id = project.team.members.find_by(username: identifier).try(:id)
         else
-          id = User.where(username: identifier).pluck(:id).first
+          id = User.find_by(username: identifier).try(:id)
         end
         users << User.find(id) unless id.blank?
       end

app/services/projects/participants_service.rb

+module Projects
+  class ParticipantsService < BaseService
+    def initialize(project)
+      @project = project
+    end
+
+    def execute(note_type, note_id)
+      participating = if note_type && note_id
+                      participants_in(note_type, note_id)
+                    else
+                      []
+                    end
+      team_members = sorted(@project.team.members)
+      participants = all_members + team_members + participating
+      participants.uniq
+    end
+
+    def participants_in(type, id)
+      users = case type
+              when "Issue"
+                issue = @project.issues.find_by_iid(id)
+                issue ? issue.participants : []
+              when "MergeRequest"
+                merge_request = @project.merge_requests.find_by_iid(id)
+                merge_request ? merge_request.participants : []
+              when "Commit"
+                author_ids = Note.for_commit_id(id).pluck(:author_id).uniq
+                User.where(id: author_ids)
+              else
+                []
+              end
+      sorted(users)
+    end
+
+    def sorted(users)
+      users.uniq.to_a.compact.sort_by(&:username).map { |user| { username: user.username, name: user.name } }
+    end
+
+    def all_members
+      [{ username: "all", name: "Project and Group Members" }]
+    end
+  end
+end

lib/gitlab/markdown.rb

@@ -169,15 +169,13 @@ module Gitlab
     end
 
     def reference_user(identifier, project = @project)
-      if identifier == "all"
-        options = html_options.merge(
+      options = html_options.merge(
           class: "gfm gfm-team_member #{html_options[:class]}"
         )
+
+      if identifier == "all"
         link_to("@all", project_url(project), options)
       elsif user = User.find_by(username: identifier)
-        options = html_options.merge(
-          class: "gfm gfm-team_member #{html_options[:class]}"
-        )
         link_to("@#{identifier}", user_url(identifier), options)
       end
     end