2 files changed, 43 insertions, 17 deletions
diff --git a/app/controllers/concerns/issuable_actions.rb b/app/controllers/concerns/issuable_actions.rb
index 6fa2f75be33..94d1e8248fc 100644
--- a/app/controllers/concerns/issuable_actions.rb
+++ b/app/controllers/concerns/issuable_actions.rb
@@ -98,13 +98,12 @@ module IssuableActions
     render json: { notice: "#{quantity} #{resource_name.pluralize(quantity)} updated" }
   end
 
-  # rubocop: disable CodeReuse/ActiveRecord
+  # rubocop:disable CodeReuse/ActiveRecord
   def discussions
-    notes = issuable.discussion_notes
-      .inc_relations_for_view
-      .with_notes_filter(notes_filter)
-      .includes(:noteable)
-      .fresh
+    notes = NotesFinder.new(project, current_user, finder_params_for_issuable).execute
+                .inc_relations_for_view
+                .includes(:noteable)
+                .fresh
 
     if notes_filter != UserPreference::NOTES_FILTERS[:only_comments]
       notes = ResourceEvents::MergeIntoNotesService.new(issuable, current_user).execute(notes)
@@ -117,7 +116,7 @@ module IssuableActions
 
     render json: discussion_serializer.represent(discussions, context: self)
   end
-  # rubocop: enable CodeReuse/ActiveRecord
+  # rubocop:enable CodeReuse/ActiveRecord
 
   private
 
@@ -222,4 +221,13 @@ module IssuableActions
   def parent
     @project || @group # rubocop:disable Gitlab/ModuleWithInstanceVariables
   end
+
+  # rubocop:disable Gitlab/ModuleWithInstanceVariables
+  def finder_params_for_issuable
+    {
+        target: @issuable,
+        notes_filter: notes_filter
+    }
+  end
+  # rubocop:enable Gitlab/ModuleWithInstanceVariables
 end
diff --git a/app/finders/notes_finder.rb b/app/finders/notes_finder.rb
index 8f610d7dddb..c25600221d7 100644
--- a/app/finders/notes_finder.rb
+++ b/app/finders/notes_finder.rb
@@ -3,6 +3,8 @@
 class NotesFinder
   FETCH_OVERLAP = 5.seconds
 
+  attr_reader :target_type
+
   # Used to filter Notes
   # When used with target_type and target_id this returns notes specifically for the controller
   #
@@ -10,6 +12,7 @@ class NotesFinder
   #   current_user - which user check authorizations with
   #   project - which project to look for notes on
   #   params:
+  #     target: noteable
   #     target_type: string
   #     target_id: integer
   #     last_fetched_at: time
@@ -18,7 +21,8 @@ class NotesFinder
   def initialize(project, current_user, params = {})
     @project = project
     @current_user = current_user
-    @params = params
+    @params = params.dup
+    @target_type = @params[:target_type]
   end
 
   def execute
@@ -32,7 +36,27 @@ class NotesFinder
   def target
     return @target if defined?(@target)
 
-    target_type = @params[:target_type]
+    if target_given?
+      use_explicit_target
+    else
+      find_target_by_type_and_ids
+    end
+  end
+
+  private
+
+  def target_given?
+    @params.key?(:target)
+  end
+
+  def use_explicit_target
+    @target = @params[:target]
+    @target_type = @target.class.name.underscore
+
+    @target
+  end
+
+  def find_target_by_type_and_ids
     target_id   = @params[:target_id]
     target_iid  = @params[:target_iid]
 
@@ -45,13 +69,11 @@ class NotesFinder
           @project.commit(target_id)
         end
       else
-        noteables_for_type_by_id(target_type, target_id, target_iid)
+        noteable_for_type_by_id(target_type, target_id, target_iid)
       end
   end
 
-  private
-
-  def noteables_for_type_by_id(type, id, iid)
+  def noteable_for_type_by_id(type, id, iid)
     query = if id
               { id: id }
             else
@@ -77,10 +99,6 @@ class NotesFinder
     search(notes)
   end
 
-  def target_type
-    @params[:target_type]
-  end
-
   # rubocop: disable CodeReuse/ActiveRecord
   def notes_of_any_type
     types = %w(commit issue merge_request snippet)