Merge branch 'auto_introduced_by_url' into 'master'

Add Danger check for empty introduced_by_url fields

See merge request gitlab-org/gitlab!95551

danger/config_files/Dangerfile

+# frozen_string_literal: true
+
+config_files.add_suggestion_for_missing_introduced_by_url

danger/plugins/config_files.rb

+# frozen_string_literal: true
+
+require_relative '../../tooling/danger/config_files'
+
+module Danger
+  class ConfigFiles < ::Danger::Plugin
+    # Put the helper code somewhere it can be tested
+    include Tooling::Danger::ConfigFiles
+  end
+end

spec/tooling/danger/config_files_spec.rb

+# frozen_string_literal: true
+
+require 'gitlab-dangerfiles'
+require 'danger'
+require 'danger/plugins/internal/helper'
+require 'gitlab/dangerfiles/spec_helper'
+
+require_relative '../../../tooling/danger/config_files'
+require_relative '../../../tooling/danger/project_helper'
+
+RSpec.describe Tooling::Danger::ConfigFiles do
+  include_context "with dangerfile"
+
+  let(:fake_danger) { DangerSpecHelper.fake_danger.include(described_class) }
+  let(:fake_project_helper) { instance_double(Tooling::Danger::ProjectHelper) }
+  let(:matching_line) { "+ introduced_by_url:" }
+
+  subject(:config_file) { fake_danger.new(helper: fake_helper) }
+
+  before do
+    allow(config_file).to receive(:project_helper).and_return(fake_project_helper)
+  end
+
+  describe '#add_suggestion_for_missing_introduced_by_url' do
+    let(:file_lines) do
+      [
+        "---",
+        "name: about_your_company_registration_flow",
+        "introduced_by_url: #{url}",
+        "rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/355909",
+        "milestone: '14.10'"
+      ]
+    end
+
+    let(:filename) { 'config/feature_flags/new_ff.yml' }
+
+    before do
+      allow(config_file.project_helper).to receive(:file_lines).and_return(file_lines)
+      allow(config_file.helper).to receive(:added_files).and_return([filename])
+      allow(config_file.helper).to receive(:mr_web_url).and_return(url)
+    end
+
+    context 'when config file has an empty introduced_by_url line' do
+      let(:url) { '' }
+
+      it 'adds suggestions at the correct line' do
+        expected_format = format(described_class::SUGGEST_INTRODUCED_BY_COMMENT, url: url)
+        expect(config_file).to receive(:markdown).with(expected_format, file: filename, line: 3)
+
+        config_file.add_suggestion_for_missing_introduced_by_url
+      end
+    end
+
+    context 'when config file has an introduced_by_url line with value' do
+      let(:url) { 'https://gitlab.com/gitlab-org/gitlab/-/issues/1' }
+
+      it 'does not add suggestion' do
+        expect(config_file).not_to receive(:markdown)
+
+        config_file.add_suggestion_for_missing_introduced_by_url
+      end
+    end
+  end
+
+  describe '#new_config_files' do
+    let(:expected_files) do
+      %w[
+        config/feature_flags/first.yml
+        config/events/1234_new_event.yml
+        config/metrics/count_7d/new_metric.yml
+      ]
+    end
+
+    before do
+      all_new_files = %w[
+        app/workers/a.rb
+        doc/events/new_event.md
+        config/feature_flags/first.yml
+        config/events/1234_new_event.yml
+        config/metrics/count_7d/new_metric.yml
+        app/assets/index.js
+      ]
+
+      allow(config_file.helper).to receive(:added_files).and_return(all_new_files)
+    end
+
+    it 'returns added, modified, and renamed_after files by default' do
+      expect(config_file.new_config_files).to match_array(expected_files)
+    end
+  end
+end

tooling/danger/config_files.rb

+# frozen_string_literal: true
+
+require 'yaml'
+
+module Tooling
+  module Danger
+    module ConfigFiles
+      SUGGEST_INTRODUCED_BY_COMMENT = <<~SUGGEST_COMMENT
+        ```suggestion
+        introduced_by_url: "%<url>s"
+        ```
+      SUGGEST_COMMENT
+
+      CONFIG_DIRS = %w[
+        config/feature_flags
+        config/metrics
+        config/events
+      ].freeze
+
+      def add_suggestion_for_missing_introduced_by_url
+        new_config_files.each do |file_name|
+          config_file_lines = project_helper.file_lines(file_name)
+
+          config_file_lines.each_with_index do |added_line, i|
+            next unless added_line =~ /^introduced_by_url:\s?$/
+
+            markdown(format(SUGGEST_INTRODUCED_BY_COMMENT, url: helper.mr_web_url), file: file_name, line: i + 1)
+          end
+        end
+      end
+
+      def new_config_files
+        helper.added_files.select { |f| in_config_dir?(f) && f.end_with?('yml') }
+      end
+
+      private
+
+      def in_config_dir?(path)
+        CONFIG_DIRS.any? { |d| path.start_with?(d) }
+      end
+    end
+  end
+end