path: root/railties/test/application/zeitwerk_integration_test.rb

# frozen_string_literal: true

require "isolation/abstract_unit"
require "active_support/dependencies/zeitwerk_integration"

class ZeitwerkIntegrationTest < ActiveSupport::TestCase
  include ActiveSupport::Testing::Isolation

  def setup
    build_app
  end

  def boot(env = "development")
    app(env)
  end

  def teardown
    teardown_app
  end

  def deps
    ActiveSupport::Dependencies
  end

  def decorated?
    deps.singleton_class < deps::ZeitwerkIntegration::Decorations
  end

  test "ActiveSupport::Dependencies is decorated by default" do
    boot

    assert decorated?
    assert_instance_of Zeitwerk::Loader, Rails.autoloader
    assert_instance_of Zeitwerk::Loader, Rails.once_autoloader
    assert_equal [Rails.autoloader, Rails.once_autoloader], Rails.autoloaders
  end

  test "ActiveSupport::Dependencies is not decorated in classic mode" do
    add_to_config "config.autoloader = :classic"
    boot

    assert_not decorated?
    assert_nil Rails.autoloader
    assert_nil Rails.once_autoloader
    assert_empty Rails.autoloaders
  end

  test "constantize returns the value stored in the constant" do
    app_file "app/models/admin/user.rb", "class Admin::User; end"
    boot

    assert_same Admin::User, deps.constantize("Admin::User")
  end

  test "constantize raises if the constant is unknown" do
    boot

    assert_raises(NameError) { deps.constantize("Admin") }
  end

  test "safe_constantize returns the value stored in the constant" do
    app_file "app/models/admin/user.rb", "class Admin::User; end"
    boot

    assert_same Admin::User, deps.safe_constantize("Admin::User")
  end

  test "safe_constantize returns nil for unknown constants" do
    boot

    assert_nil deps.safe_constantize("Admin")
  end

  test "autoloaded_constants returns autoloaded constant paths" do
    app_file "app/models/admin/user.rb", "class Admin::User; end"
    app_file "app/models/post.rb", "class Post; end"
    boot

    assert Admin::User
    assert_equal ["Admin", "Admin::User"], deps.autoloaded_constants
  end

  test "autoloaded? says if a constant has been autoloaded" do
    app_file "app/models/user.rb", "class User; end"
    app_file "app/models/post.rb", "class Post; end"
    boot

    assert Post
    assert deps.autoloaded?("Post")
    assert deps.autoloaded?(Post)
    assert_not deps.autoloaded?("User")
  end

  test "eager loading loads the application code" do
    $zeitwerk_integration_test_user = false
    $zeitwerk_integration_test_post = false

    app_file "app/models/user.rb", "class User; end; $zeitwerk_integration_test_user = true"
    app_file "app/models/post.rb", "class Post; end; $zeitwerk_integration_test_post = true"
    boot("production")

    assert $zeitwerk_integration_test_user
    assert $zeitwerk_integration_test_post
  end

  test "eager loading loads anything managed by Zeitwerk" do
    $zeitwerk_integration_test_user = false
    app_file "app/models/user.rb", "class User; end; $zeitwerk_integration_test_user = true"

    $zeitwerk_integration_test_extras = false
    app_dir "extras"
    app_file "extras/webhook_hacks.rb", "WebhookHacks = 1; $zeitwerk_integration_test_extras = true"

    require "zeitwerk"
    autoloader = Zeitwerk::Loader.new
    autoloader.push_dir("#{app_path}/extras")
    autoloader.setup

    boot("production")

    assert $zeitwerk_integration_test_user
    assert $zeitwerk_integration_test_extras
  end

  test "autoload paths that are below Gem.path go to the once autoloader" do
    app_dir "extras"
    add_to_config 'config.autoload_paths << "#{Rails.root}/extras"'

    # Mocks Gem.path to include the extras directory.
    Gem.singleton_class.prepend(
      Module.new do
        def path
          super + ["#{Rails.root}/extras"]
        end
      end
    )
    boot

    assert_not_includes Rails.autoloader.dirs, "#{app_path}/extras"
    assert_includes Rails.once_autoloader.dirs, "#{app_path}/extras"
  end

  test "clear reloads the main autoloader, and does not reload the once one" do
    boot

    $zeitwerk_integration_reload_test = []

    autoloader = Rails.autoloader
    def autoloader.reload
      $zeitwerk_integration_reload_test << :autoloader
      super
    end

    once_autoloader = Rails.once_autoloader
    def once_autoloader.reload
      $zeitwerk_integration_reload_test << :once_autoloader
      super
    end

    ActiveSupport::Dependencies.clear

    assert_equal %i(autoloader), $zeitwerk_integration_reload_test
  end
end