Add tests for checking displayed current branch in the pipeline editor

app/assets/javascripts/pipeline_editor/components/file_nav/branch_switcher.vue

@@ -212,6 +212,7 @@ export default {
     :text="currentBranch"
     icon="branch"
     data-qa-selector="branch_selector_button"
+    data-testid="branch-selector"
   >
     <gl-search-box-by-type :debounce="$options.inputDebounce" @input="setSearchTerm" />
     <gl-dropdown-section-header>

spec/features/projects/ci/editor_spec.rb

@@ -5,17 +5,55 @@ require 'spec_helper'
 RSpec.describe 'Pipeline Editor', :js do
   include Spec::Support::Helpers::Features::SourceEditorSpecHelpers
 
-  let(:project) { create(:project, :repository) }
+  let(:project) { create(:project_empty_repo, :public) }
   let(:user) { create(:user) }
 
+  let(:default_branch) { 'main' }
+  let(:other_branch) { 'test' }
+
   before do
     sign_in(user)
     project.add_developer(user)
 
+    project.repository.create_file(user, project.ci_config_path_or_default, 'Default Content', message: 'Create CI file for main', branch_name: default_branch)
+    project.repository.create_file(user, project.ci_config_path_or_default, 'Other Content', message: 'Create CI file for test', branch_name: other_branch)
+
     visit project_ci_pipeline_editor_path(project)
+    wait_for_requests
   end
 
   it 'user sees the Pipeline Editor page' do
     expect(page).to have_content('Pipeline Editor')
   end
+
+  context 'branch switcher' do
+    before do
+      stub_feature_flags(pipeline_editor_branch_switcher: true)
+    end
+
+    def switch_to_branch(branch)
+      find('[data-testid="branch-selector"]').click
+
+      page.within '[data-testid="branch-selector"]' do
+        click_button branch
+        wait_for_requests
+      end
+    end
+
+    it 'displays current branch' do
+      page.within('[data-testid="branch-selector"]') do
+        expect(page).to have_content(default_branch)
+        expect(page).not_to have_content(other_branch)
+      end
+    end
+
+    it 'displays updated current branch after switching branches' do
+      switch_to_branch(other_branch)
+
+      page.within('[data-testid="branch-selector"]') do
+        expect(page).to have_content(other_branch)
+        expect(page).not_to have_content(default_branch)
+      end
+    end
+  end
 end