Add E2E test of pipelines for merged results

Adds QA selectors.
Changes the code for expanding merge request settings to be
consistent with other similar code. And Updates the rebase merge
request test that used the old code.

app/assets/javascripts/vue_merge_request_widget/components/mr_widget_pipeline.vue

@@ -110,7 +110,10 @@ export default {
       <div class="ci-widget-container d-flex">
         <div class="ci-widget-content">
           <div class="media-body">
-            <div class="font-weight-bold js-pipeline-info-container">
+            <div
+              class="font-weight-bold js-pipeline-info-container"
+              data-qa-selector="merge_request_pipeline_info_content"
+            >
               {{ pipeline.details.name }}
               <gl-link :href="pipeline.path" class="pipeline-id font-weight-normal pipeline-number"
                 >#{{ pipeline.id }}</gl-link

ee/app/views/projects/_merge_pipelines_settings.html.haml

 - return unless merge_pipelines_available?
 
 .form-check.builds-feature
-  = form.check_box :merge_pipelines_enabled, class: 'form-check-input js-merge-options-merge-pipelines'
+  = form.check_box :merge_pipelines_enabled, class: 'form-check-input js-merge-options-merge-pipelines', data: { qa_selector: 'merged_results_pipeline_checkbox' }
   = form.label :merge_pipelines_enabled, class: 'form-check-label' do
     = s_('ProjectSettings|Merge pipelines will try to validate the post-merge result prior to merging')
     .text-secondary.mb-2

qa/qa/ee.rb

@@ -110,6 +110,7 @@ module QA
           autoload :ProtectedBranches, 'qa/ee/page/project/settings/protected_branches'
           autoload :MirroringRepositories, 'qa/ee/page/project/settings/mirroring_repositories'
           autoload :Main, 'qa/ee/page/project/settings/main'
+          autoload :MergeRequest, 'qa/ee/page/project/settings/merge_request'
           autoload :MergeRequestApproval, 'qa/ee/page/project/settings/merge_request_approval'
           autoload :Repository, 'qa/ee/page/project/settings/repository'
           autoload :PushRules, 'qa/ee/page/project/settings/push_rules'

qa/qa/ee/page/project/settings/merge_request.rb

+# frozen_string_literal: true
+
+module QA
+  module EE
+    module Page
+      module Project
+        module Settings
+          module MergeRequest
+            def self.prepended(page)
+              page.module_eval do
+                view 'ee/app/views/projects/_merge_pipelines_settings.html.haml' do
+                  element :merged_results_pipeline_checkbox
+                end
+              end
+            end
+
+            def click_pipelines_for_merged_results_checkbox
+              check_element :merged_results_pipeline_checkbox
+            end
+          end
+        end
+      end
+    end
+  end
+end

qa/qa/page/merge_request/show.rb

@@ -6,6 +6,16 @@ module QA
       class Show < Page::Base
         include Page::Component::Note
 
+        view 'app/assets/javascripts/vue_merge_request_widget/components/mr_widget_header.vue' do
+          element :dropdown_toggle
+          element :download_email_patches
+          element :download_plain_diff
+        end
+
+        view 'app/assets/javascripts/vue_merge_request_widget/components/mr_widget_pipeline.vue' do
+          element :merge_request_pipeline_info_content
+        end
+
         view 'app/assets/javascripts/vue_merge_request_widget/components/states/ready_to_merge.vue' do
           element :merge_button
           element :fast_forward_message, 'Fast-forward merge without a merge commit' # rubocop:disable QA/ElementWithPattern
@@ -27,12 +37,6 @@ module QA
           element :squash_checkbox
         end
 
-        view 'app/assets/javascripts/vue_merge_request_widget/components/mr_widget_header.vue' do
-          element :dropdown_toggle
-          element :download_email_patches
-          element :download_plain_diff
-        end
-
         view 'app/views/projects/merge_requests/show.html.haml' do
           element :notes_tab
           element :diffs_tab
@@ -111,6 +115,11 @@ module QA
           end
         end
 
+        def has_pipeline_status?(text)
+          # Pipelines can be slow, so we wait a bit longer than the usual 10 seconds
+          has_element?(:merge_request_pipeline_info_content, text: text, wait: 30)
+        end
+
         def has_title?(title)
           has_element?(:title, text: title)
         end

qa/qa/page/project/settings/main.rb

@@ -11,6 +11,7 @@ module QA
 
           view 'app/views/projects/edit.html.haml' do
             element :advanced_settings
+            element :merge_request_settings
           end
 
           view 'app/views/projects/settings/_general.html.haml' do
@@ -41,6 +42,12 @@ module QA
             end
           end
 
+          def expand_merge_requests_settings(&block)
+            expand_section(:merge_request_settings) do
+              MergeRequest.perform(&block)
+            end
+          end
+
           def expand_visibility_project_features_permissions(&block)
             expand_section(:visibility_features_permissions_content) do
               VisibilityFeaturesPermissions.perform(&block)

qa/qa/page/project/settings/merge_request.rb

@@ -8,7 +8,6 @@ module QA
           include Common
 
           view 'app/views/projects/edit.html.haml' do
-            element :merge_request_settings
             element :save_merge_request_changes
           end
 
@@ -16,14 +15,18 @@ module QA
             element :radio_button_merge_ff
           end
 
+          def click_save_changes
+            click_element :save_merge_request_changes
+          end
+
           def enable_ff_only
-            expand_section(:merge_request_settings) do
-              click_element :radio_button_merge_ff
-              click_element :save_merge_request_changes
-            end
+            click_element :radio_button_merge_ff
+            click_save_changes
           end
         end
       end
     end
   end
 end
+
+QA::Page::Project::Settings::MergeRequest.prepend_if_ee("QA::EE::Page::Project::Settings::MergeRequest")

qa/qa/specs/features/browser_ui/3_create/merge_request/rebase_merge_request_spec.rb

@@ -13,8 +13,12 @@ module QA
         end
         project.visit!
 
-        Page::Project::Menu.perform(&:click_settings)
-        Page::Project::Settings::MergeRequest.perform(&:enable_ff_only)
+        Page::Project::Menu.perform(&:go_to_general_settings)
+        Page::Project::Settings::Main.perform do |main|
+          main.expand_merge_requests_settings do |settings|
+            settings.enable_ff_only
+          end
+        end
 
         merge_request = Resource::MergeRequest.fabricate! do |merge_request|
           merge_request.project = project

qa/qa/specs/features/ee/browser_ui/6_release/pipelines_for_merged_results_spec.rb

+# frozen_string_literal: true
+
+module QA
+  context 'Release', :docker do
+    describe 'Pipelines for merged results' do
+      let(:project) do
+        Resource::Project.fabricate_via_api! do |project|
+          project.name = 'pipelines-for-merged-results'
+        end
+      end
+      let(:executor) { "qa-runner-#{Time.now.to_i}" }
+
+      before do
+        Resource::Runner.fabricate_via_api! do |runner|
+          runner.project = project
+          runner.name = executor
+          runner.tags = %w[qa test]
+        end
+
+        Resource::Repository::ProjectPush.fabricate! do |project_push|
+          project_push.project = project
+          project_push.file_name = '.gitlab-ci.yml'
+          project_push.commit_message = 'Add .gitlab-ci.yml'
+          project_push.file_content = <<~EOF
+            test:
+              script: echo 'OK'
+              only:
+              - merge_requests
+          EOF
+        end
+
+        Runtime::Browser.visit(:gitlab, Page::Main::Login)
+        Page::Main::Login.perform(&:sign_in_using_credentials)
+      end
+
+      after do
+        Service::Runner.new(executor).remove!
+      end
+
+      it 'creates a pipeline with merged results' do
+        project.visit!
+
+        Page::Project::Menu.perform(&:go_to_general_settings)
+
+        Page::Project::Settings::Main.perform do |main|
+          main.expand_merge_requests_settings do |settings|
+            settings.click_pipelines_for_merged_results_checkbox
+            settings.click_save_changes
+          end
+        end
+
+        Resource::MergeRequest.fabricate_via_api! do |merge_request|
+          merge_request.project = project
+          merge_request.target_new_branch = false
+        end.visit!
+
+        Page::MergeRequest::Show.perform do |merge_request|
+          expect(merge_request).to have_pipeline_status(/Merged result pipeline #\d+ passed/)
+
+          # The default option is to merge via merge train,
+          # but that will be covered by another test
+          merge_request.merge_immediately
+        end
+
+        expect(page).to have_content('The changes were merged')
+      end
+    end
+  end
+end