Merge branch 'fix/async-pipeline-processing-stale-data' into 'master'

Fix ci pipeline processing with async jobs

## What does this MR do?

This MR fixes CI pipeline processing with asynchronous jobs called from `around_transition` provided by state machine.
For details see  https://github.com/pluginaweek/state_machine/issues/191 and commit f68acba.

## Why was this MR needed?

Recently merged https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6650 introduced problem with asynchronous job being deployed when `around_transition` still held transaction, which caused race condition that prevented pipeline status to change in a proper way. 

## What are the relevant issue numbers?

Closes #23111

See merge request !6736

app/models/commit_status.rb

@@ -1,6 +1,7 @@
 class CommitStatus < ActiveRecord::Base
   include HasStatus
   include Importable
+  include AfterCommitQueue
 
   self.table_name = 'ci_builds'
 
@@ -85,25 +86,34 @@ class CommitStatus < ActiveRecord::Base
     end
 
     after_transition do |commit_status, transition|
-      commit_status.pipeline.try do |pipeline|
-        break if transition.loopback?
+      return if transition.loopback?
 
-        if commit_status.complete?
-          ProcessPipelineWorker.perform_async(pipeline.id)
+      commit_status.run_after_commit do
+        pipeline.try do |pipeline|
+          if complete?
+            ProcessPipelineWorker.perform_async(pipeline.id)
+          else
+            UpdatePipelineWorker.perform_async(pipeline.id)
+          end
         end
-
-        UpdatePipelineWorker.perform_async(pipeline.id)
       end
-
-      true
     end
 
     after_transition [:created, :pending, :running] => :success do |commit_status|
-      MergeRequests::MergeWhenBuildSucceedsService.new(commit_status.pipeline.project, nil).trigger(commit_status)
+      commit_status.run_after_commit do
+        # TODO, temporary fix for race condition
+        UpdatePipelineWorker.new.perform(pipeline.id)
+
+        MergeRequests::MergeWhenBuildSucceedsService
+          .new(pipeline.project, nil).trigger(self)
+      end
     end
 
     after_transition any => :failed do |commit_status|
-      MergeRequests::AddTodoWhenBuildFailsService.new(commit_status.pipeline.project, nil).execute(commit_status)
+      commit_status.run_after_commit do
+        MergeRequests::AddTodoWhenBuildFailsService
+          .new(pipeline.project, nil).execute(self)
+      end
     end
   end
 

app/services/ci/process_pipeline_service.rb

@@ -16,6 +16,8 @@ module Ci
             process_stage(index)
           end
 
+        @pipeline.update_status
+
         # Return a flag if a when builds got enqueued
         new_builds.flatten.any?
       end

spec/services/merge_requests/merge_when_build_succeeds_service_spec.rb

@@ -110,9 +110,21 @@ describe MergeRequests::MergeWhenBuildSucceedsService do
 
     context 'properly handles multiple stages' do
       let(:ref) { mr_merge_if_green_enabled.source_branch }
-      let!(:build) { create(:ci_build, :created, pipeline: pipeline, ref: ref, name: 'build', stage: 'build') }
-      let!(:test) { create(:ci_build, :created, pipeline: pipeline, ref: ref, name: 'test', stage: 'test') }
-      let(:pipeline) { create(:ci_empty_pipeline, ref: mr_merge_if_green_enabled.source_branch, project: project) }
+      let(:sha) { project.commit(ref).id }
+
+      let(:pipeline) do
+        create(:ci_empty_pipeline, ref: ref, sha: sha, project: project)
+      end
+
+      let!(:build) do
+        create(:ci_build, :created, pipeline: pipeline, ref: ref,
+                                    name: 'build', stage: 'build')
+      end
+
+      let!(:test) do
+        create(:ci_build, :created, pipeline: pipeline, ref: ref,
+                                    name: 'test', stage: 'test')
+      end
 
       before do
         # This behavior of MergeRequest: we instantiate a new object
@@ -121,14 +133,16 @@ describe MergeRequests::MergeWhenBuildSucceedsService do
         end
       end
 
-      it "doesn't merge if some stages failed" do
+      it "doesn't merge if any of stages failed" do
         expect(MergeWorker).not_to receive(:perform_async)
+
         build.success
         test.drop
       end
 
-      it 'merge when all stages succeeded' do
+      it 'merges when all stages succeeded' do
         expect(MergeWorker).to receive(:perform_async)
+
         build.success
         test.success
       end