Do not serialize a pipeline again when showing a build

This change makes it possible to avoid additional serialization of
entire pipeline when rendering a build details page. Instead we expose
more information from the build entity itself what is much cheaper than
serializing entire pipeline.

Additionally we do not need to serialize `latest?` flag, which involves
multiple Gitaly calls.

3 files changed, 7 insertions, 9 deletions

diff --git a/app/serializers/build_details_entity.rb b/app/serializers/build_details_entity.rb
index 2843132ef62..61420ce0219 100644
--- a/app/serializers/build_details_entity.rb
+++ b/app/serializers/build_details_entity.rb
@@ -8,11 +8,8 @@ class BuildDetailsEntity < JobEntity
   expose :stuck?, as: :stuck
   expose :user, using: UserEntity
   expose :runner, using: RunnerEntity
-
-  # expose :pipeline, using: PipelineEntity
-  expose :pipeline_path do |build|
-    project_pipeline_path(build.project, build.pipeline)
-  end
+  expose :metadata, using: BuildMetadataEntity
+  expose :pipeline, using: PipelineEntity
 
   expose :deployment_status, if: -> (*) { build.starts_environment? } do
     expose :deployment_status, as: :status
@@ -20,8 +17,6 @@ class BuildDetailsEntity < JobEntity
     expose :persisted_environment, as: :environment, with: EnvironmentEntity
   end
 
-  expose :metadata, using: BuildMetadataEntity
-
   expose :artifact, if: -> (*) { can?(current_user, :read_build, build) } do
     expose :download_path, if: -> (*) { build.artifacts? } do |build|
       download_project_job_artifacts_path(project, build)
diff --git a/app/serializers/pipeline_details_entity.rb b/app/serializers/pipeline_details_entity.rb
index d78ad4af4dc..dfef4364965 100644
--- a/app/serializers/pipeline_details_entity.rb
+++ b/app/serializers/pipeline_details_entity.rb
@@ -1,8 +1,11 @@
 # frozen_string_literal: true
 
 class PipelineDetailsEntity < PipelineEntity
+  expose :flags do
+    expose :latest?, as: :latest
+  end
+
   expose :details do
-    expose :ordered_stages, as: :stages, using: StageEntity
     expose :artifacts, using: BuildArtifactEntity
     expose :manual_actions, using: BuildActionEntity
     expose :scheduled_actions, using: BuildActionEntity
diff --git a/app/serializers/pipeline_entity.rb b/app/serializers/pipeline_entity.rb
index 8fe5df81e6c..9ef93b2387f 100644
--- a/app/serializers/pipeline_entity.rb
+++ b/app/serializers/pipeline_entity.rb
@@ -20,7 +20,6 @@ class PipelineEntity < Grape::Entity
   end
 
   expose :flags do
-    expose :latest?, as: :latest
     expose :stuck?, as: :stuck
     expose :auto_devops_source?, as: :auto_devops
     expose :merge_request_event?, as: :merge_request
@@ -34,6 +33,7 @@ class PipelineEntity < Grape::Entity
 
   expose :details do
     expose :detailed_status, as: :status, with: DetailedStatusEntity
+    expose :ordered_stages, as: :stages, using: StageEntity
     expose :duration
     expose :finished_at
   end