Add controller tests for commit pipelines endpoint

spec/controllers/projects/commit_controller_spec.rb

@@ -4,7 +4,6 @@ describe Projects::CommitController do
   let(:project)  { create(:project, :repository) }
   let(:user)     { create(:user) }
   let(:commit)   { project.commit("master") }
-  let(:pipeline) { create(:ci_pipeline, project: project, commit: commit) }
   let(:master_pickable_sha) { '7d3b0f7cff5f37573aea97cebfd5692ea1689924' }
   let(:master_pickable_commit)  { project.commit(master_pickable_sha) }
 
@@ -322,13 +321,28 @@ describe Projects::CommitController do
     end
 
     context 'when the commit exists' do
-      context 'when the commit has one or more pipelines' do
+      context 'when the commit has pipelines' do
+        before do
+          create(:ci_pipeline, project: project, sha: commit.id)
+        end
+
+        context 'when rendering a HTML format' do
           it 'shows pipelines' do
             get_pipelines(id: commit.id)
 
             expect(response).to be_ok
           end
         end
+
+        context 'when rendering a JSON format' do
+          it 'responds with serialized pipelines' do
+            get_pipelines(id: commit.id, format: :json)
+
+            expect(response).to be_ok
+            expect(JSON.parse(response.body)).not_to be_empty
+          end
+        end
+      end
     end
 
     context 'when the commit does not exist' do