Add project level config for merge train

We add the option and expose the parameter for frontend work

app/models/project_ci_cd_setting.rb

@@ -16,3 +16,5 @@ class ProjectCiCdSetting < ApplicationRecord
     super
   end
 end
+
+ProjectCiCdSetting.prepend(EE::ProjectCiCdSetting)

db/migrate/20190416185130_add_merge_train_enabled_to_ci_cd_settings.rb

+# frozen_string_literal: true
+
+class AddMergeTrainEnabledToCiCdSettings < ActiveRecord::Migration[5.1]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    add_column_with_default :project_ci_cd_settings, :merge_trains_enabled, :boolean, default: false, allow_null: false
+  end
+
+  def down
+    remove_column :project_ci_cd_settings, :merge_trains_enabled
+  end
+end

db/schema.rb

@@ -2314,6 +2314,7 @@ ActiveRecord::Schema.define(version: 20190426180107) do
     t.integer "project_id", null: false
     t.boolean "group_runners_enabled", default: true, null: false
     t.boolean "merge_pipelines_enabled"
+    t.boolean "merge_trains_enabled", default: false, null: false
     t.index ["project_id"], name: "index_project_ci_cd_settings_on_project_id", unique: true, using: :btree
   end
 

ee/app/controllers/ee/projects_controller.rb

@@ -50,6 +50,8 @@ module EE
         attrs << %i[merge_pipelines_enabled]
       end
 
+      attrs << %i[merge_trains_enabled] if allow_merge_trains_params?
+
       if allow_mirror_params?
         attrs + mirror_params
       else
@@ -76,5 +78,9 @@ module EE
     def allow_merge_pipelines_params?
       project&.feature_available?(:merge_pipelines)
     end
+
+    def allow_merge_trains_params?
+      project&.feature_available?(:merge_trains)
+    end
   end
 end

ee/app/helpers/ee/projects_helper.rb

@@ -121,6 +121,12 @@ module EE
       @project.feature_available?(:merge_pipelines)
     end
 
+    def merge_trains_available?
+      return false unless @project.builds_enabled?
+
+      @project.feature_available?(:merge_trains)
+    end
+
     def size_limit_message(project)
       show_lfs = project.lfs_enabled? ? 'including files in LFS' : ''
 

ee/app/models/ee/project.rb

@@ -107,6 +107,7 @@ module EE
       delegate :log_jira_dvcs_integration_usage, :jira_dvcs_server_last_sync_at, :jira_dvcs_cloud_last_sync_at, to: :feature_usage
 
       delegate :merge_pipelines_enabled, :merge_pipelines_enabled=, :merge_pipelines_enabled?, to: :ci_cd_settings
+      delegate :merge_trains_enabled, :merge_trains_enabled=, :merge_trains_enabled?, to: :ci_cd_settings
 
       validates :repository_size_limit,
         numericality: { only_integer: true, greater_than_or_equal_to: 0, allow_nil: true }
@@ -524,10 +525,6 @@ module EE
       feature_available?(:protected_environments)
     end
 
-    def merge_pipelines_enabled?
-      feature_available?(:merge_pipelines) && super
-    end
-
     # Because we use default_value_for we need to be sure
     # packages_enabled= method does exist even if we rollback migration.
     # Otherwise many tests from spec/migrations will fail.

ee/app/models/ee/project_ci_cd_setting.rb

+# frozen_string_literal: true
+
+module EE
+  module ProjectCiCdSetting
+    extend ActiveSupport::Concern
+
+    def merge_pipelines_enabled?
+      project.feature_available?(:merge_pipelines) && super
+    end
+
+    def merge_trains_enabled?
+      merge_pipelines_enabled? && project.feature_available?(:merge_trains) && super
+    end
+  end
+end

ee/app/models/license.rb

@@ -75,6 +75,7 @@ class License < ApplicationRecord
     batch_comments
     issues_analytics
     merge_pipelines
+    merge_trains
     design_management
     operations_dashboard
     dependency_proxy

ee/app/serializers/ee/merge_request_widget_entity.rb

@@ -127,6 +127,10 @@ module EE
         merge_request.target_project.merge_pipelines_enabled?
       end
 
+      expose :merge_trains_enabled?, as: :merge_trains_enabled do |merge_request|
+        merge_request.target_project.merge_trains_enabled?
+      end
+
       expose :can_push_to_source_branch do |merge_request|
         presenter(merge_request).can_push_to_source_branch?
       end

ee/changelogs/unreleased/add-project-level-config-for-merge-train.yml

+---
+title: Add project level config for merge train
+merge_request: 11065
+author:
+type: added

ee/spec/controllers/projects_controller_spec.rb

@@ -224,6 +224,48 @@ describe ProjectsController do
       end
     end
 
+    context 'when merge_trains_enabled param is specified' do
+      let(:params) { { merge_trains_enabled: true } }
+
+      let(:request) do
+        put :update, params: { namespace_id: project.namespace, id: project, project: params }
+      end
+
+      before do
+        stub_licensed_features(merge_trains: true)
+      end
+
+      it 'updates the attribute' do
+        request
+
+        expect(project.reload.merge_trains_enabled).to be_truthy
+      end
+
+      context 'when feature flag is disabled' do
+        before do
+          stub_feature_flags(merge_trains: false)
+        end
+
+        it 'does not update the attribute' do
+          request
+
+          expect(project.reload.merge_trains_enabled).to be_falsy
+        end
+      end
+
+      context 'when license is not sufficient' do
+        before do
+          stub_licensed_features(merge_trains: false)
+        end
+
+        it 'does not update the attribute' do
+          request
+
+          expect(project.reload.merge_trains_enabled).to be_falsy
+        end
+      end
+    end
+
     context 'repository mirrors' do
       let(:params) do
         {

ee/spec/models/project_ci_cd_setting_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe ProjectCiCdSetting do
+  describe '#merge_pipelines_enabled?' do
+    subject { project.merge_pipelines_enabled? }
+
+    let(:project) { create(:project) }
+    let(:merge_pipelines_enabled) { true }
+
+    before do
+      project.merge_pipelines_enabled = merge_pipelines_enabled
+    end
+
+    context 'when Merge pipelines (EEP) is available' do
+      before do
+        stub_licensed_features(merge_pipelines: true)
+      end
+
+      it { is_expected.to be_truthy }
+
+      context 'when project setting is disabled' do
+        let(:merge_pipelines_enabled) { false }
+
+        it { is_expected.to be_falsy }
+      end
+    end
+
+    context 'when Merge pipelines (EEP) is unavailable' do
+      before do
+        stub_licensed_features(merge_pipelines: false)
+      end
+
+      it { is_expected.to be_falsy }
+
+      context 'when project setting is disabled' do
+        let(:merge_pipelines_enabled) { false }
+
+        it { is_expected.to be_falsy }
+      end
+    end
+  end
+
+  describe '#merge_trains_enabled?' do
+    subject { project.merge_trains_enabled? }
+
+    let(:project) { create(:project) }
+    let(:merge_trains_enabled) { true }
+
+    before do
+      project.merge_trains_enabled = merge_trains_enabled
+    end
+
+    context 'when Merge trains (EEP) is available' do
+      before do
+        stub_licensed_features(merge_pipelines: true, merge_trains: true)
+        project.merge_pipelines_enabled = true
+      end
+
+      it { is_expected.to be_truthy }
+
+      context 'when project setting is disabled' do
+        let(:merge_trains_enabled) { false }
+
+        it { is_expected.to be_falsy }
+      end
+    end
+
+    context 'when Merge trains (EEP) is unavailable' do
+      before do
+        stub_licensed_features(merge_trains: false)
+      end
+
+      it { is_expected.to be_falsy }
+
+      context 'when project setting is disabled' do
+        let(:merge_trains_enabled) { false }
+
+        it { is_expected.to be_falsy }
+      end
+    end
+  end
+end

ee/spec/models/project_spec.rb

@@ -1745,45 +1745,6 @@ describe Project do
     end
   end
 
-  describe '#merge_pipelines_enabled?' do
-    subject { project.merge_pipelines_enabled? }
-
-    let(:project) { create(:project) }
-    let(:merge_pipelines_enabled) { true }
-
-    before do
-      project.merge_pipelines_enabled = merge_pipelines_enabled
-    end
-
-    context 'when Merge pipelines (EEP) is available' do
-      before do
-        stub_licensed_features(merge_pipelines: true)
-      end
-
-      it { is_expected.to be_truthy }
-
-      context 'when project setting is disabled' do
-        let(:merge_pipelines_enabled) { false }
-
-        it { is_expected.to be_falsy }
-      end
-    end
-
-    context 'when Merge pipelines (EEP) is unavailable' do
-      before do
-        stub_licensed_features(merge_pipelines: false)
-      end
-
-      it { is_expected.to be_falsy }
-
-      context 'when project setting is disabled' do
-        let(:merge_pipelines_enabled) { false }
-
-        it { is_expected.to be_falsy }
-      end
-    end
-  end
-
   describe "#insights_config" do
     context 'when project has no Insights config file' do
       let(:project) { create(:project) }

ee/spec/serializers/merge_request_widget_entity_spec.rb

@@ -190,4 +190,8 @@ describe MergeRequestWidgetEntity do
 
     expect(subject.as_json).to include(:pipeline_id)
   end
+
+  it 'has merge trains flag' do
+    expect(subject.as_json).to include(:merge_trains_enabled)
+  end
 end

spec/models/merge_request_spec.rb

@@ -2123,7 +2123,7 @@ describe MergeRequest do
     end
 
     context 'when merges are not restricted to green builds' do
-      subject { build(:merge_request, target_project: build(:project, only_allow_merge_if_pipeline_succeeds: false)) }
+      subject { build(:merge_request, target_project: create(:project, only_allow_merge_if_pipeline_succeeds: false)) }
 
       context 'and a failed pipeline is associated' do
         before do