Add tests for autocomplete on a Commit

spec/features/participants_autocomplete_spec.rb

@@ -7,6 +7,7 @@ feature 'Member autocomplete', feature: true do
   let(:author) { create(:user) }
 
   before do
+    allow_any_instance_of(Commit).to receive(:author).and_return(author)
     login_as user
   end
 
@@ -58,6 +59,23 @@ feature 'Member autocomplete', feature: true do
     end
   end
 
+  context 'adding a new note on a Commit ', js: true do
+    let(:commit)  { project.commit }
+
+    before do
+      allow(commit).to receive(:author).and_return(author)
+      create(:note_on_commit, author: participant, project: project, commit_id: project.repository.commit.id, note: 'No More Parties in LA')
+      visit_commit(project, commit)
+    end
+
+    context 'when typing @' do
+      include_examples "open suggestions"
+      before do
+        open_member_suggestions
+      end
+    end
+  end
+
   def open_member_suggestions
     sleep 1
     page.within('.new-note') do
@@ -73,4 +91,8 @@ feature 'Member autocomplete', feature: true do
   def visit_merge_request(project, merge)
     visit namespace_project_merge_request_path(project.namespace, project, merge)
   end
+
+  def visit_commit(project, commit)
+    visit namespace_project_commit_path(project.namespace, project, commit)
+  end
 end