Display codeclimate error when base_path is null

In the MR codeclimate widget
When the branch's base pipeline has no codeclimate artifact
Show the generic 'Failed to load codeclimate report' error message

ee/app/assets/javascripts/vue_merge_request_widget/mr_widget_options.vue

@@ -44,7 +44,7 @@ export default {
     },
     shouldRenderCodeQuality() {
       const { codeclimate } = this.mr || {};
-      return codeclimate && codeclimate.head_path && codeclimate.base_path;
+      return codeclimate && codeclimate.head_path;
     },
     shouldRenderLicenseReport() {
       const { licenseManagement } = this.mr;
@@ -102,6 +102,23 @@ export default {
 
       return text.join('');
     },
+    codequalityPopover() {
+      const { codeclimate } = this.mr || {};
+      if (codeclimate && !codeclimate.base_path) {
+        return {
+          title: s__('ciReport|Base pipeline codequality artifact not found'),
+          content: sprintf(
+            s__('ciReport|%{linkStartTag}Learn more about codequality reports %{linkEndTag}'),
+            {
+              linkStartTag: `<a href="${this.mr.codequalityHelpPath}" target="_blank" rel="noopener noreferrer">`,
+              linkEndTag: '<i class="fa fa-external-link" aria-hidden="true"></i></a>',
+            },
+            false,
+          ),
+        };
+      }
+      return {};
+    },
 
     performanceText() {
       const { improved, degraded } = this.mr.performanceMetrics;
@@ -174,11 +191,20 @@ export default {
       };
     },
     fetchCodeQuality() {
-      const { head_path, base_path } = this.mr.codeclimate;
+      const { codeclimate } = this.mr || {};
+
+      if (!codeclimate.base_path) {
+        this.isLoadingCodequality = false;
+        this.loadingCodequalityFailed = true;
+        return;
+      }
 
       this.isLoadingCodequality = true;
 
-      Promise.all([this.service.fetchReport(head_path), this.service.fetchReport(base_path)])
+      Promise.all([
+        this.service.fetchReport(codeclimate.head_path),
+        this.service.fetchReport(codeclimate.base_path),
+      ])
         .then(values =>
           this.mr.compareCodeclimateMetrics(
             values[0],
@@ -251,6 +277,7 @@ export default {
         :resolved-issues="mr.codeclimateMetrics.resolvedIssues"
         :has-issues="hasCodequalityIssues"
         :component="$options.componentNames.CodequalityIssueBody"
+        :popover-options="codequalityPopover"
         class="js-codequality-widget mr-widget-border-top mr-report"
       />
       <report-section

ee/app/assets/javascripts/vue_merge_request_widget/stores/mr_widget_store.js

@@ -21,6 +21,7 @@ export default class MergeRequestStore extends CEMergeRequestStore {
     this.vulnerabilityFeedbackPath = data.vulnerability_feedback_path;
     this.vulnerabilityFeedbackHelpPath = data.vulnerability_feedback_help_path;
     this.approvalsHelpPath = data.approvals_help_path;
+    this.codequalityHelpPath = data.codequality_help_path;
     this.securityReportsPipelineId = data.pipeline_id;
     this.createVulnerabilityFeedbackIssuePath = data.create_vulnerability_feedback_issue_path;
     this.createVulnerabilityFeedbackMergeRequestPath =

ee/app/views/projects/merge_requests/show.html.haml

@@ -15,6 +15,7 @@
     window.gl.mrWidgetData.dependency_scanning_help_path = '#{help_page_path("user/application_security/dependency_scanning/index")}';
     window.gl.mrWidgetData.vulnerability_feedback_help_path = '#{help_page_path("user/application_security/index")}';
     window.gl.mrWidgetData.approvals_help_path = '#{help_page_path("user/project/merge_requests/merge_request_approvals")}';
+    window.gl.mrWidgetData.codequality_help_path = '#{help_page_path("user/project/merge_requests/code_quality", anchor: "code-quality-reports")}';
     window.gl.mrWidgetData.visual_review_app_available = '#{@project.feature_available?(:visual_review_app)}' === 'true';
     window.gl.mrWidgetData.license_management_comparison_path = '#{license_management_reports_project_merge_request_path(@project, @merge_request) if @project.feature_available?(:license_management)}'
     window.gl.mrWidgetData.container_scanning_comparison_path = '#{container_scanning_reports_project_merge_request_path(@project, @merge_request) if @project.feature_available?(:container_scanning)}'

ee/changelogs/unreleased/14033-code-climate-message-if-report-cannot-generate.yml

+---
+title: Display generic error in codeclimate MR widget when base_path is null
+merge_request: 21666
+author:
+type: changed

ee/spec/javascripts/vue_mr_widget/ee_mr_widget_options_spec.js

@@ -417,6 +417,37 @@ describe('ee merge request widget options', () => {
       });
     });
 
+    describe('with a head_path but no base_path', () => {
+      beforeEach(() => {
+        vm = mountComponent(Component, { mrData: gl.mrWidgetData });
+
+        gl.mrWidgetData.codeclimate = {
+          head_path: 'head.json',
+          base_path: null,
+        };
+        vm.mr.codeclimate = gl.mrWidgetData.codeclimate;
+      });
+
+      it('should render error indicator', done => {
+        setTimeout(() => {
+          expect(
+            removeBreakLine(
+              vm.$el.querySelector('.js-codequality-widget .js-code-text').textContent,
+            ),
+          ).toContain('Failed to load codeclimate report');
+          done();
+        }, 0);
+      });
+
+      it('should render a help icon with more information', done => {
+        setTimeout(() => {
+          expect(vm.$el.querySelector('.js-codequality-widget .btn-help')).not.toBeNull();
+          expect(vm.codequalityPopover.title).toBe('Base pipeline codequality artifact not found');
+          done();
+        }, 0);
+      });
+    });
+
     describe('with codeclimate comparison worker rejection', () => {
       beforeEach(() => {
         mock.onGet('head.json').reply(200, headIssues);

locale/gitlab.pot

@@ -21791,6 +21791,9 @@ msgstr ""
 msgid "ciReport|%{linkStartTag}Learn more about SAST %{linkEndTag}"
 msgstr ""
 
+msgid "ciReport|%{linkStartTag}Learn more about codequality reports %{linkEndTag}"
+msgstr ""
+
 msgid "ciReport|%{namespace} is affected by %{vulnerability}."
 msgstr ""
 
@@ -21879,6 +21882,9 @@ msgstr ""
 msgid "ciReport|Automatically apply the patch in a new branch"
 msgstr ""
 
+msgid "ciReport|Base pipeline codequality artifact not found"
+msgstr ""
+
 msgid "ciReport|Class"
 msgstr ""