Extract Pipeline add-job service to remove duplicate logic

We are using the same logic in three difference places, and here
we are unifying the usage.

app/services/ci/pipeline_creation/add_job_service.rb

+# frozen_string_literal: true
+
+module Ci
+  module PipelineCreation
+    class AddJobService
+      attr_reader :pipeline
+
+      def initialize(pipeline)
+        @pipeline = pipeline
+
+        raise "Pipeline must be persisted for this service to be used" unless @pipeline.persisted?
+      end
+
+      def execute(job, save: true)
+        assign_pipeline_attributes(job)
+
+        Ci::Pipeline.transaction do
+          BulkInsertableAssociations.with_bulk_insert { job.save! } if save
+
+          job.update_older_statuses_retried! if Feature.enabled?(:ci_fix_commit_status_retried, @pipeline.project, default_enabled: :yaml)
+        end
+
+        job
+      end
+
+      private
+
+      def assign_pipeline_attributes(job)
+        # these also ensures other invariants such as
+        # a job takes project and ref from the pipeline it belongs to
+        job.pipeline = @pipeline
+        job.project = @pipeline.project
+        job.ref = @pipeline.ref
+      end
+    end
+  end
+end

app/services/ci/retry_build_service.rb

@@ -34,18 +34,11 @@ module Ci
     def reprocess!(build)
       check_access!(build)
 
-      attributes = self.class.clone_accessors.to_h do |attribute|
-        [attribute, build.public_send(attribute)] # rubocop:disable GitlabSecurity/PublicSend
-      end
+      new_build = clone_build(build)
+      ::Ci::PipelineCreation::AddJobService.new(build.pipeline).execute(new_build)
+      build.reset # refresh the data to get new values of `retried` and `processed`.
 
-      attributes[:user] = current_user
-
-      Ci::Build.transaction do
-        create_build!(attributes).tap do |new_build|
-          new_build.update_older_statuses_retried!
-          build.reset # refresh the data to get new values of `retried` and `processed`.
-        end
-      end
+      new_build
     end
     # rubocop: enable CodeReuse/ActiveRecord
 
@@ -59,13 +52,19 @@ module Ci
 
     def check_assignable_runners!(build); end
 
-    def create_build!(attributes)
-      build = project.builds.new(attributes)
-      build.assign_attributes(::Gitlab::Ci::Pipeline::Seed::Build.environment_attributes_for(build))
-      BulkInsertableAssociations.with_bulk_insert do
-        build.save!
+    def clone_build(build)
+      project.builds.new(build_attributes(build)).tap do |new_build|
+        new_build.assign_attributes(::Gitlab::Ci::Pipeline::Seed::Build.environment_attributes_for(new_build))
       end
-      build
+    end
+
+    def build_attributes(build)
+      attributes = self.class.clone_accessors.to_h do |attribute|
+        [attribute, build.public_send(attribute)] # rubocop:disable GitlabSecurity/PublicSend
+      end
+
+      attributes[:user] = current_user
+      attributes
     end
   end
 end

app/services/projects/update_pages_service.rb

@@ -31,8 +31,9 @@ module Projects
       register_attempt
 
       # Create status notifying the deployment of pages
-      @status = create_status
-      @status.update_older_statuses_retried! if Feature.enabled?(:ci_fix_commit_status_retried, project, default_enabled: :yaml)
+      @status = build_commit_status
+      ::Ci::PipelineCreation::AddJobService.new(@build.pipeline).execute(@status)
+
       @status.enqueue!
       @status.run!
 
@@ -70,12 +71,9 @@ module Projects
       super
     end
 
-    def create_status
+    def build_commit_status
       GenericCommitStatus.new(
-        project: project,
-        pipeline: build.pipeline,
         user: build.user,
-        ref: build.ref,
         stage: 'deploy',
         name: 'pages:deploy'
       )

lib/api/commit_statuses.rb

@@ -100,7 +100,7 @@ module API
         status.assign_attributes(attributes_for_keys(updatable_optional_attributes))
 
         if status.valid?
-          status.update_older_statuses_retried! if Feature.enabled?(:ci_fix_commit_status_retried, user_project, default_enabled: :yaml)
+          ::Ci::PipelineCreation::AddJobService.new(pipeline).execute(status, save: false)
         else
           render_validation_error!(status)
         end

spec/services/ci/pipeline_creation/add_job_service_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Ci::PipelineCreation::AddJobService do
+  let_it_be(:pipeline) { create(:ci_pipeline) }
+
+  let(:job) { build(:ci_build) }
+
+  subject(:service) { described_class.new(pipeline) }
+
+  context 'when the pipeline is not persisted' do
+    let(:pipeline) { build(:ci_pipeline) }
+
+    it 'raises error' do
+      expect { service }.to raise_error('Pipeline must be persisted for this service to be used')
+    end
+  end
+
+  it 'assigns pipeline attributes to the job' do
+    expect do
+      service.execute(job)
+    end.to change { job.slice(:pipeline, :project, :ref) }.to(
+      pipeline: pipeline, project: pipeline.project, ref: pipeline.ref
+    )
+  end
+
+  it 'returns the job itself' do
+    expect(service.execute(job)).to eq(job)
+  end
+
+  it 'calls update_older_statuses_retried!' do
+    expect(job).to receive(:update_older_statuses_retried!)
+
+    service.execute(job)
+  end
+
+  context 'when the FF ci_fix_commit_status_retried is disabled' do
+    before do
+      stub_feature_flags(ci_fix_commit_status_retried: false)
+    end
+
+    it 'does not call update_older_statuses_retried!' do
+      expect(job).not_to receive(:update_older_statuses_retried!)
+
+      service.execute(job)
+    end
+  end
+end