Optimize pipeline entity spec

Make database creation more efficent and
only add setup code where it is needed

spec/serializers/pipeline_entity_spec.rb

@@ -7,18 +7,8 @@ RSpec.describe PipelineEntity do
 
   let_it_be(:project) { create(:project) }
   let_it_be(:user) { create(:user) }
-  let(:request) { double('request') }
-
-  before do
-    stub_not_protect_default_branch
-
-    allow(request).to receive(:current_user).and_return(user)
-    allow(request).to receive(:project).and_return(project)
-  end
-
-  let(:entity) do
-    described_class.represent(pipeline, request: request)
-  end
+  let(:request) { double('request', current_user: user) }
+  let(:entity) { described_class.represent(pipeline, request: request) }
 
   describe '#as_json' do
     subject { entity.as_json }
@@ -54,10 +44,13 @@ RSpec.describe PipelineEntity do
       end
     end
 
-    context 'when pipeline is retryable' do
-      let(:project) { create(:project) }
+    context 'when default branch not protected' do
+      before do
+        stub_not_protect_default_branch
+      end
 
-      let(:pipeline) do
+      context 'when pipeline is retryable' do
+        let_it_be(:pipeline) do
           create(:ci_pipeline, status: :success, project: project)
         end
 
@@ -89,9 +82,7 @@ RSpec.describe PipelineEntity do
       end
 
       context 'when pipeline is cancelable' do
-      let(:project) { create(:project) }
-
-      let(:pipeline) do
+        let_it_be(:pipeline) do
           create(:ci_pipeline, status: :running, project: project)
         end
 
@@ -121,6 +112,7 @@ RSpec.describe PipelineEntity do
           end
         end
       end
+    end
 
     context 'delete path' do
       context 'user has ability to delete pipeline' do
@@ -133,7 +125,6 @@ RSpec.describe PipelineEntity do
       end
 
       context 'user does not have ability to delete pipeline' do
-        let(:project) { create(:project) }
         let(:pipeline) { create(:ci_pipeline, project: project) }
 
         it 'does not contain delete path' do
@@ -167,8 +158,13 @@ RSpec.describe PipelineEntity do
       end
     end
 
+    context 'when request has a project' do
+      before do
+        allow(request).to receive(:project).and_return(project)
+      end
+
       context 'when pipeline is detached merge request pipeline' do
-      let(:merge_request) { create(:merge_request, :with_detached_merge_request_pipeline) }
+        let_it_be(:merge_request) { create(:merge_request, :with_detached_merge_request_pipeline) }
         let(:project) { merge_request.target_project }
         let(:pipeline) { merge_request.pipelines_for_merge_request.first }
 
@@ -216,7 +212,7 @@ RSpec.describe PipelineEntity do
       end
 
       context 'when pipeline is merge request pipeline' do
-      let(:merge_request) { create(:merge_request, :with_merge_request_pipeline, merge_sha: 'abc') }
+        let_it_be(:merge_request) { create(:merge_request, :with_merge_request_pipeline, merge_sha: 'abc') }
         let(:project) { merge_request.target_project }
         let(:pipeline) { merge_request.pipelines_for_merge_request.first }
 
@@ -237,9 +233,10 @@ RSpec.describe PipelineEntity do
           expect(subject[:merge_request_event_type]).to be_present
         end
       end
+    end
 
     context 'when pipeline has failed builds' do
-      let_it_be(:pipeline) { create(:ci_pipeline, project: project, user: user) }
+      let_it_be(:pipeline) { create(:ci_pipeline, user: user) }
       let_it_be(:build) { create(:ci_build, :success, pipeline: pipeline) }
       let_it_be(:failed_1) { create(:ci_build, :failed, pipeline: pipeline) }
       let_it_be(:failed_2) { create(:ci_build, :failed, pipeline: pipeline) }