rails/railties/test/application/loading_test.rb

# frozen_string_literal: true

require "isolation/abstract_unit"

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

  def setup
    build_app
  end

  def teardown
    teardown_app
  end

  def app
    @app ||= Rails.application
  end

  test "constants in app are autoloaded" do
    app_file "app/models/post.rb", <<-MODEL
      class Post < ActiveRecord::Base
        validates_acceptance_of :title, accept: "omg"
      end
    MODEL

    require "#{rails_root}/config/environment"
    setup_ar!

    p = Post.create(title: "omg")
    assert_equal 1, Post.count
    assert_equal "omg", p.title
    p = Post.first
    assert_equal "omg", p.title
  end

  test "constants without a matching file raise NameError" do
    app_file "app/models/post.rb", <<-RUBY
      class Post
        NON_EXISTING_CONSTANT
      end
    RUBY

    boot_app

    e = assert_raise(NameError) { User }
    assert_equal "uninitialized constant #{self.class}::User", e.message

    e = assert_raise(NameError) { Post }
    assert_equal "uninitialized constant Post::NON_EXISTING_CONSTANT", e.message
  end

  test "concerns in app are autoloaded" do
    app_file "app/controllers/concerns/trackable.rb", <<-CONCERN
      module Trackable
      end
    CONCERN

    app_file "app/mailers/concerns/email_loggable.rb", <<-CONCERN
      module EmailLoggable
      end
    CONCERN

    app_file "app/models/concerns/orderable.rb", <<-CONCERN
      module Orderable
      end
    CONCERN

    app_file "app/validators/concerns/matchable.rb", <<-CONCERN
      module Matchable
      end
    CONCERN

    require "#{rails_root}/config/environment"

    assert_nothing_raised { Trackable }
    assert_nothing_raised { EmailLoggable }
    assert_nothing_raised { Orderable }
    assert_nothing_raised { Matchable }
  end

  test "models without table do not panic on scope definitions when loaded" do
    app_file "app/models/user.rb", <<-MODEL
      class User < ActiveRecord::Base
        default_scope { where(published: true) }
      end
    MODEL

    require "#{rails_root}/config/environment"
    setup_ar!

    User
  end

  test "load config/environments/environment before Bootstrap initializers" do
    app_file "config/environments/development.rb", <<-RUBY
      Rails.application.configure do
        config.development_environment_loaded = true
      end
    RUBY

    add_to_config <<-RUBY
      config.before_initialize do
        config.loaded = config.development_environment_loaded
      end
    RUBY

    require "#{app_path}/config/environment"
    assert ::Rails.application.config.loaded
  end

  test "descendants loaded after framework initialization are cleaned on each request without cache classes" do
    add_to_config <<-RUBY
      config.cache_classes = false
      config.reload_classes_only_on_change = false
    RUBY

    app_file "app/models/post.rb", <<-MODEL
      class Post < ApplicationRecord
      end
    MODEL

    app_file "config/routes.rb", <<-RUBY
      Rails.application.routes.draw do
        get '/load',   to: lambda { |env| [200, {}, Post.all] }
        get '/unload', to: lambda { |env| [200, {}, []] }
      end
    RUBY

    require "rack/test"
    extend Rack::Test::Methods

    require "#{rails_root}/config/environment"
    setup_ar!

    initial = [ActiveStorage::Blob, ActiveStorage::Attachment, ActiveRecord::SchemaMigration, ActiveRecord::InternalMetadata, ApplicationRecord, "primary::SchemaMigration"].collect(&:to_s).sort
    assert_equal initial, ActiveRecord::Base.descendants.collect(&:to_s).sort
    get "/load"
    assert_equal [Post].collect(&:to_s).sort, ActiveRecord::Base.descendants.collect(&:to_s).sort - initial
    get "/unload"
    assert_equal ["ActiveRecord::InternalMetadata", "ActiveRecord::SchemaMigration", "primary::SchemaMigration"], ActiveRecord::Base.descendants.collect(&:to_s).sort.uniq
  end

  test "initialize cant be called twice" do
    require "#{app_path}/config/environment"
    assert_raise(RuntimeError) { Rails.application.initialize! }
  end

  test "reload constants on development" do
    add_to_config <<-RUBY
      config.cache_classes = false
    RUBY

    app_file "config/routes.rb", <<-RUBY
      Rails.application.routes.draw do
        get '/c', to: lambda { |env| [200, {"Content-Type" => "text/plain"}, [User.counter.to_s]] }
      end
    RUBY

    app_file "app/models/user.rb", <<-MODEL
      class User
        def self.counter; 1; end
      end
    MODEL

    require "rack/test"
    extend Rack::Test::Methods

    require "#{rails_root}/config/environment"

    get "/c"
    assert_equal "1", last_response.body

    app_file "app/models/user.rb", <<-MODEL
      class User
        def self.counter; 2; end
      end
    MODEL

    get "/c"
    assert_equal "2", last_response.body
  end

  test "does not reload constants on development if custom file watcher always returns false" do
    add_to_config <<-RUBY
      config.cache_classes = false
      config.file_watcher = Class.new do
        def initialize(*); end
        def updated?; false; end
        def execute; end
        def execute_if_updated; false; end
      end
    RUBY

    app_file "config/routes.rb", <<-RUBY
      Rails.application.routes.draw do
        get '/c', to: lambda { |env| [200, {"Content-Type" => "text/plain"}, [User.counter.to_s]] }
      end
    RUBY

    app_file "app/models/user.rb", <<-MODEL
      class User
        def self.counter; 1; end
      end
    MODEL

    require "rack/test"
    extend Rack::Test::Methods

    require "#{rails_root}/config/environment"

    get "/c"
    assert_equal "1", last_response.body

    app_file "app/models/user.rb", <<-MODEL
      class User
        def self.counter; 2; end
      end
    MODEL

    get "/c"
    assert_equal "1", last_response.body
  end

  test "added files (like db/schema.rb) also trigger reloading" do
    add_to_config <<-RUBY
      config.cache_classes = false
    RUBY

    app_file "config/routes.rb", <<-RUBY
      $counter ||= 0
      Rails.application.routes.draw do
        get '/c', to: lambda { |env| User.name; [200, {"Content-Type" => "text/plain"}, [$counter.to_s]] }
      end
    RUBY

    app_file "app/models/user.rb", <<-MODEL
      class User
        $counter += 1
      end
    MODEL

    require "rack/test"
    extend Rack::Test::Methods

    require "#{rails_root}/config/environment"

    get "/c"
    assert_equal "1", last_response.body

    app_file "db/schema.rb", ""

    get "/c"
    assert_equal "2", last_response.body
  end

  test "dependencies reloading is followed by routes reloading" do
    add_to_config <<-RUBY
      config.cache_classes = false
    RUBY

    app_file "config/routes.rb", <<-RUBY
      $counter ||= 1
      $counter  *= 2
      Rails.application.routes.draw do
        get '/c', to: lambda { |env| User.name; [200, {"Content-Type" => "text/plain"}, [$counter.to_s]] }
      end
    RUBY

    app_file "app/models/user.rb", <<-MODEL
      class User
        $counter += 1
      end
    MODEL

    require "rack/test"
    extend Rack::Test::Methods

    require "#{rails_root}/config/environment"

    get "/c"
    assert_equal "3", last_response.body

    app_file "db/schema.rb", ""

    get "/c"
    assert_equal "7", last_response.body
  end

  test "columns migrations also trigger reloading" do
    add_to_config <<-RUBY
      config.cache_classes = false
    RUBY

    app_file "config/routes.rb", <<-RUBY
      Rails.application.routes.draw do
        get '/title', to: lambda { |env| [200, {"Content-Type" => "text/plain"}, [Post.new.title]] }
        get '/body',  to: lambda { |env| [200, {"Content-Type" => "text/plain"}, [Post.new.body]] }
      end
    RUBY

    app_file "app/models/post.rb", <<-MODEL
      class Post < ActiveRecord::Base
      end
    MODEL

    require "rack/test"
    extend Rack::Test::Methods

    app_file "db/migrate/1_create_posts.rb", <<-MIGRATION
      class CreatePosts < ActiveRecord::Migration::Current
        def change
          create_table :posts do |t|
            t.string :title, default: "TITLE"
          end
        end
      end
    MIGRATION

    rails("db:migrate")
    require "#{rails_root}/config/environment"

    get "/title"
    assert_equal "TITLE", last_response.body

    app_file "db/migrate/2_add_body_to_posts.rb", <<-MIGRATION
      class AddBodyToPosts < ActiveRecord::Migration::Current
        def change
          add_column :posts, :body, :text, default: "BODY"
        end
      end
    MIGRATION

    rails("db:migrate")

    get "/body"
    assert_equal "BODY", last_response.body
  end

  test "AC load hooks can be used with metal" do
    app_file "app/controllers/omg_controller.rb", <<-RUBY
      begin
        class OmgController < ActionController::Metal
          ActiveSupport.run_load_hooks(:action_controller, self)
          def show
            self.response_body = ["OK"]
          end
        end
      rescue => e
        puts "Error loading metal: \#{e.class} \#{e.message}"
      end
    RUBY

    app_file "config/routes.rb", <<-RUBY
      Rails.application.routes.draw do
        get "/:controller(/:action)"
      end
    RUBY

    require "#{rails_root}/config/environment"

    require "rack/test"
    extend Rack::Test::Methods

    get "/omg/show"
    assert_equal "OK", last_response.body
  end

  def test_initialize_can_be_called_at_any_time
    require "#{app_path}/config/application"

    assert_not_predicate Rails, :initialized?
    assert_not_predicate Rails.application, :initialized?
    Rails.initialize!
    assert_predicate Rails, :initialized?
    assert_predicate Rails.application, :initialized?
  end

  test "frameworks aren't loaded during initialization" do
    app_file "config/initializers/raise_when_frameworks_load.rb", <<-RUBY
      %i(action_controller action_mailer active_job active_record action_view).each do |framework|
        ActiveSupport.on_load(framework) { raise "\#{framework} loaded!" }
      end
    RUBY

    assert_nothing_raised do
      require "#{app_path}/config/environment"
    end
  end

  test "active record query cache hooks are installed before first request in production" do
    app_file "app/controllers/omg_controller.rb", <<-RUBY
      begin
        class OmgController < ActionController::Metal
          ActiveSupport.run_load_hooks(:action_controller, self)
          def show
            if ActiveRecord::Base.connection.query_cache_enabled
              self.response_body = ["Query cache is enabled."]
            else
              self.response_body = ["Expected ActiveRecord::Base.connection.query_cache_enabled to be true"]
            end
          end
        end
      rescue => e
        puts "Error loading metal: \#{e.class} \#{e.message}"
      end
    RUBY

    app_file "config/routes.rb", <<-RUBY
      Rails.application.routes.draw do
        get "/:controller(/:action)"
      end
    RUBY

    boot_app "production"

    require "rack/test"
    extend Rack::Test::Methods

    get "/omg/show"
    assert_equal "Query cache is enabled.", last_response.body
  end

  test "active record query cache hooks are installed before first request in development" do
    app_file "app/controllers/omg_controller.rb", <<-RUBY
      begin
        class OmgController < ActionController::Metal
          ActiveSupport.run_load_hooks(:action_controller, self)
          def show
            if ActiveRecord::Base.connection.query_cache_enabled
              self.response_body = ["Query cache is enabled."]
            else
              self.response_body = ["Expected ActiveRecord::Base.connection.query_cache_enabled to be true"]
            end
          end
        end
      rescue => e
        puts "Error loading metal: \#{e.class} \#{e.message}"
      end
    RUBY

    app_file "config/routes.rb", <<-RUBY
      Rails.application.routes.draw do
        get "/:controller(/:action)"
      end
    RUBY

    boot_app "development"

    require "rack/test"
    extend Rack::Test::Methods

    get "/omg/show"
    assert_equal "Query cache is enabled.", last_response.body
  end

  private
    def setup_ar!
      ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:")
      ActiveRecord::Migration.verbose = false
      ActiveRecord::Schema.define(version: 1) do
        create_table :posts do |t|
          t.string :title
        end
      end
    end

    def boot_app(env = "development")
      ENV["RAILS_ENV"] = env

      require "#{app_path}/config/environment"
    ensure
      ENV.delete "RAILS_ENV"
    end
end