Refactor codequality job artifact presentation

This refactors the codequality MR widget specs to test with real data.

ee/app/models/ee/ci/pipeline.rb

@@ -43,7 +43,10 @@ module EE
 
             return OpenStruct.new(build: build, path: file_name)
           end
-        end.last
+        end
+
+        # In case there is no artifact return nil
+        nil
       end
 
       def performance_artifact

ee/app/presenters/ee/ci/pipeline_presenter.rb

@@ -8,10 +8,10 @@ module EE
 
       def downloadable_url_for_report_type(file_type)
         if (job_artifact = artifact_for_file_type(file_type)) &&
-            can?(current_user, :read_build, job_artifact.build)
+            can?(current_user, :read_build, job_artifact.job)
           return download_project_build_artifacts_url(
             job_artifact.project,
-            job_artifact.build,
+            job_artifact.job,
             file_type: file_type)
         end
 

ee/app/serializers/ee/merge_request_widget_entity.rb

@@ -16,13 +16,13 @@ module EE
         end
       end
 
-      expose :codeclimate, if: -> (mr, _) { mr.head_pipeline&.present&.downloadable_url_for_report_type(:codequality) } do
+      expose :codeclimate, if: -> (mr, _) { head_pipeline_downloadable_url_for_report_type(mr, :codequality) } do
         expose :head_path do |merge_request|
-          merge_request.head_pipeline.present.downloadable_url_for_report_type(:codequality)
+          head_pipeline_downloadable_url_for_report_type(merge_request, :codequality)
         end
 
         expose :base_path do |merge_request|
-          merge_request.base_pipeline.present.downloadable_url_for_report_type(:codequality)
+          base_pipeline_downloadable_url_for_report_type(merge_request, :codequality)
         end
       end
 
@@ -167,5 +167,15 @@ module EE
         presenter(merge_request).approvals_path
       end
     end
+
+    private
+
+    def head_pipeline_downloadable_url_for_report_type(merge_request, file_type)
+      merge_request.head_pipeline&.present&.downloadable_url_for_report_type(file_type)
+    end
+
+    def base_pipeline_downloadable_url_for_report_type(merge_request, file_type)
+      merge_request.base_pipeline&.present&.downloadable_url_for_report_type(file_type)
+    end
   end
 end

ee/spec/models/ci/pipeline_spec.rb

@@ -170,6 +170,7 @@ describe Ci::Pipeline do
     let(:file_type) { :codequality }
     let!(:build) { create(:ci_build, pipeline: pipeline) }
     let!(:artifact) { create(:ci_job_artifact, :codequality, job: build) }
+
     subject { pipeline.artifact_for_file_type(file_type) }
 
     it 'returns the artifact' do

ee/spec/serializers/merge_request_widget_entity_spec.rb

@@ -26,14 +26,31 @@ describe MergeRequestWidgetEntity do
     expect(subject.as_json[:blob_path]).to include(:head_path)
   end
 
-  it 'has codeclimate data' do
-    allow(merge_request).to receive_messages(
-      base_pipeline: pipeline,
-      head_pipeline: pipeline
-    )
-    allow_any_instance_of(EE::Ci::PipelinePresenter).to receive(:downloadable_url_for_report_type).and_return("dummy/url")
+  describe 'codeclimate' do
+    before do
+      allow(merge_request).to receive_messages(
+        base_pipeline: pipeline,
+        head_pipeline: pipeline
+      )
+      allow_any_instance_of(Ci::PipelinePresenter).to receive(:current_user).and_return(user)
+    end
+
+    context 'with codeclimate data' do
+      before do
+        job = create(:ci_build, pipeline: pipeline)
+        create(:ci_job_artifact, :codequality, job: job)
+      end
 
-    expect(subject.as_json).to include(:codeclimate)
+      it 'has codeclimate data entry' do
+        expect(subject.as_json).to include(:codeclimate)
+      end
+    end
+
+    context 'without codeclimate data' do
+      it 'does not have codeclimate data entry' do
+        expect(subject.as_json).not_to include(:codeclimate)
+      end
+    end
   end
 
   it 'sets approvals_before_merge to 0 if nil' do