Add feature specs for CI minutes analytics

ee/app/assets/javascripts/ci_minutes_usage/components/minutes_usage_project_chart.vue

@@ -78,7 +78,7 @@ export default {
   <div>
     <div class="gl-display-flex gl-my-3">
       <h5 class="gl-flex-grow-1">{{ $options.USAGE_BY_PROJECT }}</h5>
-      <gl-dropdown v-if="!isDataEmpty" :text="selectedMonth">
+      <gl-dropdown v-if="!isDataEmpty" :text="selectedMonth" data-testid="project-month-dropdown">
         <gl-dropdown-item
           v-for="(month, index) in months"
           :key="index"

ee/spec/features/ci/ci_minutes_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe 'CI minutes', :js do
+  let_it_be(:user) { create(:user) }
+  let_it_be(:project) { create(:project, name: 'Project 1', namespace: user.namespace) }
+
+  def create_ci_minutes_usage(minutes, date)
+    create(:ci_namespace_monthly_usage, namespace: user.namespace, amount_used: minutes, date: date)
+    create(:ci_project_monthly_usage, project: project, amount_used: minutes, date: date)
+  end
+
+  before do
+    create_ci_minutes_usage(50, Date.new(2021, 5, 1))
+    create_ci_minutes_usage(60, Date.new(2021, 6, 1))
+
+    sign_in(user)
+
+    visit profile_usage_quotas_path
+  end
+
+  it 'renders a dropdown with the months of available analytics' do
+    wait_for_requests
+
+    page.find('[data-testid="project-month-dropdown"]').click
+
+    page.within '[data-testid="project-month-dropdown"]' do
+      expect(page.all('.gl-new-dropdown-item').size).to eq 2
+    end
+  end
+end