Finding discussions in NotesFinder is no longer required.

app/finders/notes_finder.rb

@@ -11,7 +11,6 @@ class NotesFinder
   #     target_type: string
   #     target_id: integer
   #     last_fetched_at: time
-  #     discussion_id: string
   #     search: string
   #
   def initialize(project, current_user, params = {})
@@ -23,7 +22,6 @@ class NotesFinder
 
   def execute
     @notes = since_fetch_at(@params[:last_fetched_at]) if @params[:last_fetched_at]
-    @notes = for_discussion(@params[:discussion_id]) if @params[:discussion_id]
     @notes
   end
 
@@ -102,8 +100,4 @@ class NotesFinder
 
     @notes.where('updated_at > ?', last_fetched_at - FETCH_OVERLAP).fresh
   end
-
-  def for_discussion(discussion_id)
-    @notes.where(discussion_id: discussion_id)
-  end
 end

spec/finders/notes_finder_spec.rb

@@ -41,17 +41,6 @@ describe NotesFinder do
       expect(notes.count).to eq(0)
     end
 
-    context 'for a certain discussion' do
-      let!(:note_in_a_commit_discussion) { create(:note_on_commit, project: project) }
-      let!(:other_note) { create(:note_on_merge_request, project: project) }
-
-      it 'finds the only the notes for a certain discussion id' do
-        notes = described_class.new(project, user, discussion_id: note_in_a_commit_discussion.discussion_id).execute
-
-        expect(notes).to contain_exactly(note_in_a_commit_discussion)
-      end
-    end
-
     context 'on restricted projects' do
       let(:project) do
         create(:empty_project,