Add tests for codeclimate related backend code

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/models/merge_request.rb

@@ -922,4 +922,10 @@ class MergeRequest < ActiveRecord::Base
   def base_codeclimate_artifact
     @base_codeclimate_artifact ||= base_pipeline&.codeclimate_artifact
   end
+
+  def has_codeclimate_data?
+    has_ci? &&
+      codeclimate_artifact&.success? &&
+      base_codeclimate_artifact&.success?
+  end
 end

app/serializers/merge_request_entity.rb

@@ -184,9 +184,7 @@ class MergeRequestEntity < IssuableEntity
                                                                merge_request)
   end
-  expose :codeclimate, if: lambda { |mr, _| mr.has_ci? &&
-                                    mr.codeclimate_artifact&.success? &&
-                                    mr.base_codeclimate_artifact&.success? } do
+  expose :codeclimate, if: lambda { |mr, _| mr.has_codeclimate_data? } do
     expose :head do |merge_request|
       raw_namespace_project_build_artifacts_url(merge_request.project.namespace,
                                                 merge_request.project,

spec/models/ci/pipeline_spec.rb

@@ -1208,4 +1208,24 @@ describe Ci::Pipeline, models: true do
       it_behaves_like 'not sending any notification'
     end
   end
+
+  describe '#codeclimate_artifact' do
+    let!(:build) do
+      create(
+        :ci_build,
+        :artifacts,
+        name: 'codeclimate',
+        pipeline: pipeline,
+        options: {
+          artifacts: {
+            paths: ['codeclimate.json']
+          }
+        }
+      )
+    end
+
+    it do
+      expect(pipeline.codeclimate_artifact).to eq(build)
+    end
+  end
 end

spec/models/merge_request_spec.rb

@@ -1536,4 +1536,10 @@ describe MergeRequest, models: true do
       end
     end
   end
+
+  describe '#base_pipeline' do
+    let!(:pipeline) { create(:ci_empty_pipeline, project: subject.project, sha: subject.diff_base_sha) }
+
+    it { expect(subject.base_pipeline).to eq(pipeline) }
+  end
 end