Suggest to use match_array instead of match for array expectation

danger/plugins/specs.rb

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

danger/specs/Dangerfile

@@ -32,11 +32,12 @@ request specs (and/or feature specs). Please add request specs under
 See https://gitlab.com/groups/gitlab-org/-/epics/5076 for information.
 MSG
 
-has_app_changes = helper.all_changed_files.grep(%r{\A(app|lib|db/(geo/)?(post_)?migrate)/}).any?
-has_ee_app_changes = helper.all_changed_files.grep(%r{\Aee/(app|lib|db/(geo/)?(post_)?migrate)/}).any?
-spec_changes = helper.all_changed_files.grep(%r{\Aspec/})
+all_changed_files = helper.all_changed_files
+has_app_changes = all_changed_files.grep(%r{\A(app|lib|db/(geo/)?(post_)?migrate)/}).any?
+has_ee_app_changes = all_changed_files.grep(%r{\Aee/(app|lib|db/(geo/)?(post_)?migrate)/}).any?
+spec_changes = specs.changed_specs_files(ee: :exclude)
 has_spec_changes = spec_changes.any?
-has_ee_spec_changes = helper.all_changed_files.grep(%r{\Aee/spec/}).any?
+has_ee_spec_changes = specs.changed_specs_files(ee: :only).any?
 new_specs_needed = (gitlab.mr_labels & NO_SPECS_LABELS).empty?
 
 if (has_app_changes || has_ee_app_changes) && !(has_spec_changes || has_ee_spec_changes) && new_specs_needed
@@ -49,6 +50,10 @@ if has_ee_app_changes && has_spec_changes && !(has_app_changes || has_ee_spec_ch
 end
 
 # Forbidding a new file addition under `/spec/controllers` or `/ee/spec/controllers`
-if git.added_files.grep(%r{^(ee/)?spec/controllers/}).any?
+if project_helper.changes.added.files.grep(%r{^(ee/)?spec/controllers/}).any?
   warn CONTROLLER_SPEC_DEPRECATION_MESSAGE
 end
+
+specs.changed_specs_files.each do |filename|
+  specs.add_suggestions_for_match_with_array(filename)
+end

spec/tooling/danger/project_helper_spec.rb

@@ -280,4 +280,17 @@ RSpec.describe Tooling::Danger::ProjectHelper do
       is_expected.to eq('gitlab-foss')
     end
   end
+
+  describe '#file_lines' do
+    let(:filename) { 'spec/foo_spec.rb' }
+    let(:file_spy) { spy }
+
+    it 'returns the chomped file lines' do
+      expect(project_helper).to receive(:read_file).with(filename).and_return(file_spy)
+
+      project_helper.file_lines(filename)
+
+      expect(file_spy).to have_received(:lines).with(chomp: true)
+    end
+  end
 end

spec/tooling/danger/specs_spec.rb

+# frozen_string_literal: true
+
+require 'rspec-parameterized'
+require 'gitlab-dangerfiles'
+require 'danger'
+require 'danger/plugins/helper'
+require 'gitlab/dangerfiles/spec_helper'
+
+require_relative '../../../tooling/danger/specs'
+require_relative '../../../tooling/danger/project_helper'
+
+RSpec.describe Tooling::Danger::Specs do
+  include_context "with dangerfile"
+
+  let(:fake_danger) { DangerSpecHelper.fake_danger.include(described_class) }
+  let(:fake_project_helper) { double('fake-project-helper', helper: fake_helper).tap { |h| h.class.include(Tooling::Danger::ProjectHelper) } }
+  let(:file_lines) do
+    [
+      " describe 'foo' do",
+      " expect(foo).to match(['bar'])",
+      " end",
+      " expect(foo).to match(['bar'])", # same line as line 1 above, we expect two different suggestions
+      " ",
+      " expect(foo).to match ['bar']",
+      " expect(foo).to eq(['bar'])",
+      " expect(foo).to eq ['bar']",
+      " expect(foo).to(match(['bar']))",
+      " expect(foo).to(eq(['bar']))",
+      " foo.eq(['bar'])"
+    ]
+  end
+
+  let(:matching_lines) do
+    [
+      "+ expect(foo).to match(['bar'])",
+      "+ expect(foo).to match(['bar'])",
+      "+ expect(foo).to match ['bar']",
+      "+ expect(foo).to eq(['bar'])",
+      "+ expect(foo).to eq ['bar']",
+      "+ expect(foo).to(match(['bar']))",
+      "+ expect(foo).to(eq(['bar']))"
+    ]
+  end
+
+  subject(:specs) { fake_danger.new(helper: fake_helper) }
+
+  before do
+    allow(specs).to receive(:project_helper).and_return(fake_project_helper)
+  end
+
+  describe '#add_suggestions_for_match_with_array' do
+    let(:filename) { 'spec/foo_spec.rb' }
+
+    before do
+      expect(specs).to receive(:added_line_matching_match_with_array).and_return(matching_lines)
+      allow(specs.project_helper).to receive(:file_lines).and_return(file_lines)
+    end
+
+    it 'adds suggestions at the correct lines' do
+      expect(specs).to receive(:markdown).with(format(described_class::SUGGEST_MR_COMMENT, suggested_line: " expect(foo).to match_array(['bar'])"), file: filename, line: 2)
+      expect(specs).to receive(:markdown).with(format(described_class::SUGGEST_MR_COMMENT, suggested_line: " expect(foo).to match_array(['bar'])"), file: filename, line: 4)
+      expect(specs).to receive(:markdown).with(format(described_class::SUGGEST_MR_COMMENT, suggested_line: " expect(foo).to match_array ['bar']"), file: filename, line: 6)
+      expect(specs).to receive(:markdown).with(format(described_class::SUGGEST_MR_COMMENT, suggested_line: " expect(foo).to match_array(['bar'])"), file: filename, line: 7)
+      expect(specs).to receive(:markdown).with(format(described_class::SUGGEST_MR_COMMENT, suggested_line: " expect(foo).to match_array ['bar']"), file: filename, line: 8)
+      expect(specs).to receive(:markdown).with(format(described_class::SUGGEST_MR_COMMENT, suggested_line: " expect(foo).to(match_array(['bar']))"), file: filename, line: 9)
+      expect(specs).to receive(:markdown).with(format(described_class::SUGGEST_MR_COMMENT, suggested_line: " expect(foo).to(match_array(['bar']))"), file: filename, line: 10)
+
+      specs.add_suggestions_for_match_with_array(filename)
+    end
+  end
+
+  describe '#changed_specs_files' do
+    let(:base_expected_files) { %w[spec/foo_spec.rb ee/spec/foo_spec.rb spec/bar_spec.rb ee/spec/bar_spec.rb spec/zab_spec.rb ee/spec/zab_spec.rb] }
+
+    before do
+      all_changed_files = %w[
+        app/workers/a.rb
+        app/workers/b.rb
+        app/workers/e.rb
+        spec/foo_spec.rb
+        ee/spec/foo_spec.rb
+        spec/bar_spec.rb
+        ee/spec/bar_spec.rb
+        spec/zab_spec.rb
+        ee/spec/zab_spec.rb
+      ]
+
+      allow(specs.helper).to receive(:all_changed_files).and_return(all_changed_files)
+    end
+
+    it 'returns added, modified, and renamed_after files by default' do
+      expect(specs.changed_specs_files).to match_array(base_expected_files)
+    end
+
+    context 'with include_ee: :exclude' do
+      it 'returns spec files without EE-specific files' do
+        expect(specs.changed_specs_files(ee: :exclude)).not_to include(%w[ee/spec/foo_spec.rb ee/spec/bar_spec.rb ee/spec/zab_spec.rb])
+      end
+    end
+
+    context 'with include_ee: :only' do
+      it 'returns EE-specific spec files only' do
+        expect(specs.changed_specs_files(ee: :only)).to match_array(%w[ee/spec/foo_spec.rb ee/spec/bar_spec.rb ee/spec/zab_spec.rb])
+      end
+    end
+  end
+
+  describe '#added_line_matching_match_with_array' do
+    let(:filename) { 'spec/foo_spec.rb' }
+    let(:changed_lines) do
+      [
+        "  expect(foo).to match(['bar'])",
+        "  expect(foo).to match(['bar'])",
+        "  expect(foo).to match ['bar']",
+        "  expect(foo).to eq(['bar'])",
+        "  expect(foo).to eq ['bar']",
+        "- expect(foo).to match(['bar'])",
+        "- expect(foo).to match(['bar'])",
+        "- expect(foo).to match ['bar']",
+        "- expect(foo).to eq(['bar'])",
+        "- expect(foo).to eq ['bar']"
+      ] + matching_lines
+    end
+
+    before do
+      allow(specs.helper).to receive(:changed_lines).with(filename).and_return(changed_lines)
+    end
+
+    it 'returns added, modified, and renamed_after files by default' do
+      expect(specs.added_line_matching_match_with_array(filename)).to match_array(matching_lines)
+    end
+  end
+end

tooling/danger/project_helper.rb

@@ -175,8 +175,16 @@ module Tooling
         ee? ? 'gitlab' : 'gitlab-foss'
       end
 
+      def file_lines(filename)
+        read_file(filename).lines(chomp: true)
+      end
+
       private
 
+      def read_file(filename)
+        File.read(filename)
+      end
+
       def ee?
         # Support former project name for `dev` and support local Danger run
         %w[gitlab gitlab-ee].include?(ENV['CI_PROJECT_NAME']) || Dir.exist?(File.expand_path('../../../ee', __dir__))

tooling/danger/specs.rb

+# frozen_string_literal: true
+
+module Tooling
+  module Danger
+    module Specs
+      SPEC_FILES_REGEX = 'spec/'
+      EE_PREFIX = 'ee/'
+      MATCH_WITH_ARRAY_REGEX = /(?<to>to\(?\s*)(?<matcher>match|eq)(?<expectation>[( ]?\[)/.freeze
+      SUGGEST_MR_COMMENT = <<~SUGGEST_COMMENT
+      ```suggestion
+      %<suggested_line>s
+      ```
+
+      If order of the result is not important, please consider using `match_array` to avoid flakiness.
+      SUGGEST_COMMENT
+
+      def changed_specs_files(ee: :include)
+        changed_files = helper.all_changed_files
+        folder_prefix =
+          case ee
+          when :include
+            "(#{EE_PREFIX})?"
+          when :only
+            EE_PREFIX
+          when :exclude
+            nil
+          end
+
+        changed_files.grep(%r{\A#{folder_prefix}#{SPEC_FILES_REGEX}})
+      end
+
+      def add_suggestions_for_match_with_array(filename)
+        added_lines = added_line_matching_match_with_array(filename)
+        return if added_lines.empty?
+
+        spec_file_lines = project_helper.file_lines(filename)
+
+        added_lines.each_with_object([]) do |added_line, processed_line_numbers|
+          line_number = find_line_number(spec_file_lines, added_line.delete_prefix('+'), exclude_indexes: processed_line_numbers)
+          processed_line_numbers << line_number
+          markdown(format(SUGGEST_MR_COMMENT, suggested_line: spec_file_lines[line_number].gsub(MATCH_WITH_ARRAY_REGEX, '\k<to>match_array\k<expectation>')), file: filename, line: line_number.succ)
+        end
+      end
+
+      def added_line_matching_match_with_array(filename)
+        helper.changed_lines(filename).grep(/\A\+ /).grep(MATCH_WITH_ARRAY_REGEX)
+      end
+
+      private
+
+      def find_line_number(file_lines, searched_line, exclude_indexes: [])
+        file_lines.each_with_index do |file_line, index|
+          next if exclude_indexes.include?(index)
+          break index if file_line == searched_line
+        end
+      end
+    end
+  end
+end