Add has_trace to Projects::JobController#show.json

closes https://gitlab.com/gitlab-org/gitlab-ce/issues/51925

app/serializers/build_details_entity.rb

@@ -7,6 +7,7 @@ class BuildDetailsEntity < JobEntity
 
   expose :coverage, :erased_at, :duration
   expose :tag_list, as: :tags
+  expose :has_trace?, as: :has_trace
   expose :user, using: UserEntity
   expose :runner, using: RunnerEntity
   expose :pipeline, using: PipelineEntity

changelogs/unreleased/51925-expose-has_trace-in-job-api.yml

+---
+title: Expose has_trace in job API
+merge_request: 21950
+author:
+type: other

spec/controllers/projects/jobs_controller_spec.rb

@@ -337,6 +337,22 @@ describe Projects::JobsController, :clean_gitlab_redis_shared_state do
           end
         end
       end
+
+      context 'when no trace is available' do
+        it 'has_trace is false' do
+          expect(response).to match_response_schema('job/job_details')
+          expect(json_response['has_trace']).to be false
+        end
+      end
+
+      context 'when job has trace' do
+        let(:job) { create(:ci_build, :running, :trace_live, pipeline: pipeline) }
+
+        it "has_trace is true" do
+          expect(response).to match_response_schema('job/job_details')
+          expect(json_response['has_trace']).to be true
+        end
+      end
     end
 
     context 'when requesting JSON job is triggered' do

spec/fixtures/api/schemas/job/job_details.json

@@ -3,12 +3,16 @@
     { "$ref": "job.json" }
   ],
   "description": "An extension of job.json with more detailed information",
+  "required": [
+    "has_trace"
+  ],
   "properties": {
     "artifact": { "$ref": "artifact.json" },
     "terminal_path": { "type": "string" },
     "trigger": { "$ref": "trigger.json" },
     "deployment_status": { "$ref": "deployment_status.json" },
     "runner": { "$ref": "runner.json" },
-    "runners": { "type": "runners.json" }
+    "runners": { "type": "runners.json" },
+    "has_trace": { "type": "boolean" }
   }
 }