Test Danger bot

danger/feature_flag/Dangerfile

@@ -41,6 +41,19 @@ def message_for_feature_flag_missing_group!(feature_flag:, mr_group_label:)
   end
 end
 
+def message_for_global_rollout(feature_flag)
+  return unless feature_flag.default_enabled == true
+
+  message = <<~SUGGEST_COMMENT
+  You're about to [release the feature with the feature flag](https://gitlab.com/gitlab-org/gitlab/-/blob/master/.gitlab/issue_templates/Feature%20Flag%20Roll%20Out.md#optional-release-the-feature-with-the-feature-flag).
+  This process can only be done **after** the [global rollout on production](https://gitlab.com/gitlab-org/gitlab/-/blob/master/.gitlab/issue_templates/Feature%20Flag%20Roll%20Out.md#global-rollout-on-production).
+  Please make sure in [the rollout issue](#{feature_flag.rollout_issue_url}) that the preliminary steps have already been done. Otherwise, changing the YAML definition might not have the desired effect.
+  SUGGEST_COMMENT
+
+  mr_line = feature_flag.raw.lines.find_index { |l| l.include?('default_enabled:') }
+  markdown(message, file: feature_flag.path, line: mr_line.succ)
+end
+
 def message_for_feature_flag_with_group!(feature_flag:, mr_group_label:)
   return if feature_flag.group_match_mr_label?(mr_group_label)
 
@@ -65,6 +78,10 @@ feature_flag.feature_flag_files(change_type: :added).each do |feature_flag|
   check_feature_flag_yaml(feature_flag)
 end
 
+feature_flag.feature_flag_files(change_type: :modified).each do |feature_flag|
+  message_for_global_rollout(feature_flag)
+end
+
 if helper.security_mr? && feature_flag_file_added?
   fail "Feature flags are discouraged from security merge requests. Read the [security documentation](https://gitlab.com/gitlab-org/release/docs/-/blob/master/general/security/utilities/feature_flags.md) for details."
 end

spec/tooling/danger/feature_flag_spec.rb

@@ -87,7 +87,11 @@ RSpec.describe Tooling::Danger::FeatureFlag do
     let(:feature_flag_path) { 'config/feature_flags/development/entry.yml' }
     let(:group) { 'group::source code' }
     let(:raw_yaml) do
-      YAML.dump('group' => group)
+      YAML.dump(
+        'group' => group,
+        'default_enabled' => true,
+        'rollout_issue_url' => 'https://gitlab.com/gitlab-org/gitlab/-/issues/1'
+      )
     end
 
     subject(:found) { described_class.new(feature_flag_path) }
@@ -109,6 +113,18 @@ RSpec.describe Tooling::Danger::FeatureFlag do
       end
     end
 
+    describe '#default_enabled' do
+      it 'returns the default_enabled found in the YAML' do
+        expect(found.default_enabled).to eq(true)
+      end
+    end
+
+    describe '#rollout_issue_url' do
+      it 'returns the rollout_issue_url found in the YAML' do
+        expect(found.rollout_issue_url).to eq('https://gitlab.com/gitlab-org/gitlab/-/issues/1')
+      end
+    end
+
     describe '#group_match_mr_label?' do
       subject(:result) { found.group_match_mr_label?(mr_group_label) }
 

tooling/danger/feature_flag.rb

@@ -29,6 +29,14 @@ module Tooling
           @group ||= yaml['group']
         end
 
+        def default_enabled
+          @default_enabled ||= yaml['default_enabled']
+        end
+
+        def rollout_issue_url
+          @rollout_issue_url ||= yaml['rollout_issue_url']
+        end
+
         def group_match_mr_label?(mr_group_label)
           mr_group_label == group
         end