Add test report API route

This adds a route to get the JSON test report content as it's
available via the UI.

Includes request specs and a minor update to the description
of an existing related controller spec.

Adds documentation

Notes API access in CI docs

changelogs/unreleased/202525-add-test-report-api-route.yml

+---
+title: Add test report API route
+merge_request: 24648
+author:
+type: added

doc/api/pipelines.md

@@ -130,6 +130,62 @@ Example of response
 ]
 ```
 
+### Get a pipeline's test report
+
+> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/202525) in GitLab 13.0.
+
+CAUTION: **Caution:**
+This API route is part of the [JUnit test report](../ci/junit_test_reports.md) feature. It is protected by a [feature flag](../development/feature_flags/index.md) that is **disabled** due to performance issues with very large data sets. See [the documentation for the feature](../ci/junit_test_reports.md#enabling-the-feature) for further details.
+
+```plaintext
+GET /projects/:id/pipelines/:pipeline_id/test_report
+```
+
+| Attribute  | Type    | Required | Description         |
+|------------|---------|----------|---------------------|
+| `id`       | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
+| `pipeline_id` | integer | yes      | The ID of a pipeline   |
+
+Sample request:
+
+```shell
+curl --header "PRIVATE-TOKEN: <your_access_token>" "https://gitlab.example.com/api/v4/projects/1/pipelines/46/test_report"
+```
+
+Sample response:
+
+```json
+{
+  "total_time": 5,
+  "total_count": 1,
+  "success_count": 1,
+  "failed_count": 0,
+  "skipped_count": 0,
+  "error_count": 0,
+  "test_suites": [
+    {
+      "name": "Secure",
+      "total_time": 5,
+      "total_count": 1,
+      "success_count": 1,
+      "failed_count": 0,
+      "skipped_count": 0,
+      "error_count": 0,
+      "test_cases": [
+        {
+          "status": "success",
+          "name": "Security Reports can create an auto-remediation MR",
+          "classname": "vulnerability_management_spec",
+          "execution_time": 5,
+          "system_output": null,
+          "stack_trace": null
+        }
+      ]
+    }
+  ]
+}
+```
+
 ## Create a new pipeline
 
 > [Introduced](https://gitlab.com/gitlab-org/gitlab-foss/-/merge_requests/7209) in GitLab 8.14

doc/ci/junit_test_reports.md

@@ -237,6 +237,8 @@ You can view all the known test suites and click on each of these to see further
 details, including the cases that makeup the suite. Cases are ordered by status,
 with failed showing at the top, skipped next and successful cases last.
 
+You can also retrieve the reports via the [GitLab API](../api/pipelines.md#get-a-pipelines-test-report).
+
 ### Enabling the feature
 
 This feature comes with the `:junit_pipeline_view` feature flag disabled by default. This

lib/api/pipelines.rb

@@ -108,6 +108,21 @@ module API
         present pipeline.variables, with: Entities::Variable
       end
 
+      desc 'Gets the test report for a given pipeline' do
+        detail 'This feature was introduced in GitLab 13.0. Disabled by default behind feature flag `junit_pipeline_view`'
+        success TestReportEntity
+      end
+      params do
+        requires :pipeline_id, type: Integer, desc: 'The pipeline ID'
+      end
+      get ':id/pipelines/:pipeline_id/test_report' do
+        not_found! unless Feature.enabled?(:junit_pipeline_view, user_project)
+
+        authorize! :read_build, pipeline
+
+        present pipeline.test_reports, with: TestReportEntity
+      end
+
       desc 'Deletes a pipeline' do
         detail 'This feature was introduced in GitLab 11.6'
         http_codes [[204, 'Pipeline was deleted'], [403, 'Forbidden']]

spec/requests/api/pipelines_spec.rb

@@ -714,4 +714,73 @@ describe API::Pipelines do
       end
     end
   end
+
+  describe 'GET /projects/:id/pipelines/:pipeline_id/test_report' do
+    context 'authorized user' do
+      subject { get api("/projects/#{project.id}/pipelines/#{pipeline.id}/test_report", user) }
+
+      let(:pipeline) { create(:ci_pipeline, project: project) }
+
+      context 'when feature is enabled' do
+        before do
+          stub_feature_flags(junit_pipeline_view: true)
+        end
+
+        context 'when pipeline does not have a test report' do
+          it 'returns an empty test report' do
+            subject
+
+            expect(response).to have_gitlab_http_status(:ok)
+            expect(json_response['total_count']).to eq(0)
+          end
+        end
+
+        context 'when pipeline has a test report' do
+          let(:pipeline) { create(:ci_pipeline, :with_test_reports, project: project) }
+
+          it 'returns the test report' do
+            subject
+
+            expect(response).to have_gitlab_http_status(:ok)
+            expect(json_response['total_count']).to eq(4)
+          end
+        end
+
+        context 'when pipeline has corrupt test reports' do
+          before do
+            job = create(:ci_build, pipeline: pipeline)
+            create(:ci_job_artifact, :junit_with_corrupted_data, job: job, project: project)
+          end
+
+          it 'returns a suite_error' do
+            subject
+
+            expect(response).to have_gitlab_http_status(:ok)
+            expect(json_response['test_suites'].first['suite_error']).to eq('JUnit XML parsing failed: 1:1: FATAL: Document is empty')
+          end
+        end
+      end
+
+      context 'when feature is disabled' do
+        before do
+          stub_feature_flags(junit_pipeline_view: false)
+        end
+
+        it 'renders empty response' do
+          subject
+
+          expect(response).to have_gitlab_http_status(:not_found)
+        end
+      end
+    end
+
+    context 'unauthorized user' do
+      it 'does not return project pipelines' do
+        get api("/projects/#{project.id}/pipelines/#{pipeline.id}/test_report", non_member)
+
+        expect(response).to have_gitlab_http_status(:not_found)
+        expect(json_response['message']).to eq '404 Project Not Found'
+      end
+    end
+  end
 end