33 files changed, 1641 insertions, 999 deletions

diff --git a/railties/test/generators/actions_test.rb b/railties/test/generators/actions_test.rb
index 3b2b3c37d0..3ecfb4edd9 100644
--- a/railties/test/generators/actions_test.rb
+++ b/railties/test/generators/actions_test.rb
@@ -1,6 +1,8 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/rails/app/app_generator'
-require 'env_helpers'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/app/app_generator"
+require "env_helpers"
 
 class ActionsTest < Rails::Generators::TestCase
   include GeneratorsTestHelper
@@ -19,98 +21,105 @@ class ActionsTest < Rails::Generators::TestCase
   end
 
   def test_invoke_other_generator_with_shortcut
-    action :invoke, 'model', ['my_model']
-    assert_file 'app/models/my_model.rb', /MyModel/
+    action :invoke, "model", ["my_model"]
+    assert_file "app/models/my_model.rb", /MyModel/
   end
 
   def test_invoke_other_generator_with_full_namespace
-    action :invoke, 'rails:model', ['my_model']
-    assert_file 'app/models/my_model.rb', /MyModel/
+    action :invoke, "rails:model", ["my_model"]
+    assert_file "app/models/my_model.rb", /MyModel/
   end
 
   def test_create_file_should_write_data_to_file_path
-    action :create_file, 'lib/test_file.rb', 'heres test data'
-    assert_file 'lib/test_file.rb', 'heres test data'
+    action :create_file, "lib/test_file.rb", "heres test data"
+    assert_file "lib/test_file.rb", "heres test data"
   end
 
   def test_create_file_should_write_block_contents_to_file_path
-    action(:create_file, 'lib/test_file.rb'){ 'heres block data' }
-    assert_file 'lib/test_file.rb', 'heres block data'
+    action(:create_file, "lib/test_file.rb") { "heres block data" }
+    assert_file "lib/test_file.rb", "heres block data"
   end
 
   def test_add_source_adds_source_to_gemfile
     run_generator
-    action :add_source, 'http://gems.github.com'
-    assert_file 'Gemfile', /source 'http:\/\/gems\.github\.com'/
+    action :add_source, "http://gems.github.com"
+    assert_file "Gemfile", /source 'http:\/\/gems\.github\.com'/
   end
 
   def test_add_source_with_block_adds_source_to_gemfile_with_gem
     run_generator
-    action :add_source, 'http://gems.github.com' do
-      gem 'rspec-rails'
+    action :add_source, "http://gems.github.com" do
+      gem "rspec-rails"
     end
-    assert_file 'Gemfile', /source 'http:\/\/gems\.github\.com' do\n  gem 'rspec-rails'\nend/
+    assert_file "Gemfile", /source 'http:\/\/gems\.github\.com' do\n  gem 'rspec-rails'\nend/
   end
 
   def test_add_source_with_block_adds_source_to_gemfile_after_gem
     run_generator
-    action :gem, 'will-paginate'
-    action :add_source, 'http://gems.github.com' do
-      gem 'rspec-rails'
+    action :gem, "will-paginate"
+    action :add_source, "http://gems.github.com" do
+      gem "rspec-rails"
     end
-    assert_file 'Gemfile', /gem 'will-paginate'\nsource 'http:\/\/gems\.github\.com' do\n  gem 'rspec-rails'\nend/
+    assert_file "Gemfile", /gem 'will-paginate'\nsource 'http:\/\/gems\.github\.com' do\n  gem 'rspec-rails'\nend/
   end
 
   def test_gem_should_put_gem_dependency_in_gemfile
     run_generator
-    action :gem, 'will-paginate'
-    assert_file 'Gemfile', /gem 'will\-paginate'/
+    action :gem, "will-paginate"
+    assert_file "Gemfile", /gem 'will\-paginate'/
   end
 
   def test_gem_with_version_should_include_version_in_gemfile
     run_generator
-
-    action :gem, 'rspec', '>=2.0.0.a5'
-
-    assert_file 'Gemfile', /gem 'rspec', '>=2.0.0.a5'/
+    action :gem, "rspec", ">= 2.0.0.a5"
+    action :gem, "RedCloth", ">= 4.1.0", "< 4.2.0"
+    action :gem, "nokogiri", version: ">= 1.4.2"
+    action :gem, "faker", version: [">= 0.1.0", "< 0.3.0"]
+
+    assert_file "Gemfile" do |content|
+      assert_match(/gem 'rspec', '>= 2\.0\.0\.a5'/, content)
+      assert_match(/gem 'RedCloth', '>= 4\.1\.0', '< 4\.2\.0'/, content)
+      assert_match(/gem 'nokogiri', '>= 1\.4\.2'/, content)
+      assert_match(/gem 'faker', '>= 0\.1\.0', '< 0\.3\.0'/, content)
+    end
   end
 
   def test_gem_should_insert_on_separate_lines
     run_generator
 
-    File.open('Gemfile', 'a') {|f| f.write('# Some content...') }
+    File.open("Gemfile", "a") { |f| f.write("# Some content...") }
 
-    action :gem, 'rspec'
-    action :gem, 'rspec-rails'
+    action :gem, "rspec"
+    action :gem, "rspec-rails"
 
-    assert_file 'Gemfile', /^gem 'rspec'$/
-    assert_file 'Gemfile', /^gem 'rspec-rails'$/
+    assert_file "Gemfile", /^gem 'rspec'$/
+    assert_file "Gemfile", /^gem 'rspec-rails'$/
   end
 
   def test_gem_should_include_options
     run_generator
 
-    action :gem, 'rspec', github: 'dchelimsky/rspec', tag: '1.2.9.rc1'
+    action :gem, "rspec", github: "dchelimsky/rspec", tag: "1.2.9.rc1"
 
-    assert_file 'Gemfile', /gem 'rspec', github: 'dchelimsky\/rspec', tag: '1\.2\.9\.rc1'/
+    assert_file "Gemfile", /gem 'rspec', github: 'dchelimsky\/rspec', tag: '1\.2\.9\.rc1'/
   end
 
   def test_gem_with_non_string_options
     run_generator
 
-    action :gem, 'rspec', require: false
-    action :gem, 'rspec-rails', group: [:development, :test]
+    action :gem, "rspec", require: false
+    action :gem, "rspec-rails", group: [:development, :test]
 
-    assert_file 'Gemfile', /^gem 'rspec', require: false$/
-    assert_file 'Gemfile', /^gem 'rspec-rails', group: \[:development, :test\]$/
+    assert_file "Gemfile", /^gem 'rspec', require: false$/
+    assert_file "Gemfile", /^gem 'rspec-rails', group: \[:development, :test\]$/
   end
 
   def test_gem_falls_back_to_inspect_if_string_contains_single_quote
     run_generator
 
-    action :gem, 'rspec', ">=2.0'0"
+    action :gem, "rspec", ">=2.0'0"
 
-    assert_file 'Gemfile', /^gem 'rspec', ">=2\.0'0"$/
+    assert_file "Gemfile", /^gem 'rspec', ">=2\.0'0"$/
   end
 
   def test_gem_works_even_if_frozen_string_is_passed_as_argument
@@ -118,115 +127,175 @@ class ActionsTest < Rails::Generators::TestCase
 
     action :gem, "frozen_gem".freeze, "1.0.0".freeze
 
-    assert_file 'Gemfile', /^gem 'frozen_gem', '1.0.0'$/
+    assert_file "Gemfile", /^gem 'frozen_gem', '1.0.0'$/
   end
 
   def test_gem_group_should_wrap_gems_in_a_group
     run_generator
 
     action :gem_group, :development, :test do
-      gem 'rspec-rails'
+      gem "rspec-rails"
     end
 
     action :gem_group, :test do
-      gem 'fakeweb'
+      gem "fakeweb"
     end
 
-    assert_file 'Gemfile', /\ngroup :development, :test do\n  gem 'rspec-rails'\nend\n\ngroup :test do\n  gem 'fakeweb'\nend/
+    assert_file "Gemfile", /\ngroup :development, :test do\n  gem 'rspec-rails'\nend\n\ngroup :test do\n  gem 'fakeweb'\nend/
   end
 
   def test_environment_should_include_data_in_environment_initializer_block
     run_generator
     autoload_paths = 'config.autoload_paths += %w["#{Rails.root}/app/extras"]'
     action :environment, autoload_paths
-    assert_file 'config/application.rb', /  class Application < Rails::Application\n    #{Regexp.escape(autoload_paths)}/
+    assert_file "config/application.rb", /  class Application < Rails::Application\n    #{Regexp.escape(autoload_paths)}\n/
   end
 
   def test_environment_should_include_data_in_environment_initializer_block_with_env_option
     run_generator
     autoload_paths = 'config.autoload_paths += %w["#{Rails.root}/app/extras"]'
-    action :environment, autoload_paths, env: 'development'
-    assert_file "config/environments/development.rb", /Rails\.application\.configure do\n  #{Regexp.escape(autoload_paths)}/
+    action :environment, autoload_paths, env: "development"
+    assert_file "config/environments/development.rb", /Rails\.application\.configure do\n  #{Regexp.escape(autoload_paths)}\n/
   end
 
   def test_environment_with_block_should_include_block_contents_in_environment_initializer_block
     run_generator
 
     action :environment do
-      _ = '# This wont be added'# assignment to silence parse-time warning "unused literal ignored"
-      '# This will be added'
+      _ = "# This wont be added"# assignment to silence parse-time warning "unused literal ignored"
+      "# This will be added"
     end
 
-    assert_file 'config/application.rb' do |content|
+    assert_file "config/application.rb" do |content|
       assert_match(/# This will be added/, content)
       assert_no_match(/# This wont be added/, content)
     end
   end
 
+  def test_environment_with_block_should_include_block_contents_with_multiline_data_in_environment_initializer_block
+    run_generator
+    data = <<-RUBY
+      config.encoding = "utf-8"
+      config.time_zone = "UTC"
+    RUBY
+    action(:environment) { data }
+    assert_file "config/application.rb", /  class Application < Rails::Application\n#{Regexp.escape(data.strip_heredoc.indent(4))}/
+  end
+
+  def test_environment_should_include_block_contents_with_multiline_data_in_environment_initializer_block_with_env_option
+    run_generator
+    data = <<-RUBY
+      config.encoding = "utf-8"
+      config.time_zone = "UTC"
+    RUBY
+    action(:environment, nil, env: "development") { data }
+    assert_file "config/environments/development.rb", /Rails\.application\.configure do\n#{Regexp.escape(data.strip_heredoc.indent(2))}/
+  end
+
   def test_git_with_symbol_should_run_command_using_git_scm
-    assert_called_with(generator, :run, ['git init']) do
+    assert_called_with(generator, :run, ["git init"]) do
       action :git, :init
     end
   end
 
   def test_git_with_hash_should_run_each_command_using_git_scm
     assert_called_with(generator, :run, [ ["git rm README"], ["git add ."] ]) do
-      action :git, rm: 'README', add: '.'
+      action :git, rm: "README", add: "."
     end
   end
 
   def test_vendor_should_write_data_to_file_in_vendor
-    action :vendor, 'vendor_file.rb', '# vendor data'
-    assert_file 'vendor/vendor_file.rb', '# vendor data'
+    action :vendor, "vendor_file.rb", "# vendor data"
+    assert_file "vendor/vendor_file.rb", "# vendor data\n"
+  end
+
+  def test_vendor_should_write_data_to_file_with_block_in_vendor
+    code = <<-RUBY
+      puts "one"
+      puts "two"
+      puts "three"
+    RUBY
+    action(:vendor, "vendor_file.rb") { code }
+    assert_file "vendor/vendor_file.rb", code.strip_heredoc
   end
 
   def test_lib_should_write_data_to_file_in_lib
-    action :lib, 'my_library.rb', 'class MyLibrary'
-    assert_file 'lib/my_library.rb', 'class MyLibrary'
+    action :lib, "my_library.rb", "class MyLibrary"
+    assert_file "lib/my_library.rb", "class MyLibrary\n"
+  end
+
+  def test_lib_should_write_data_to_file_with_block_in_lib
+    code = <<-RUBY
+      class MyLib
+        MY_CONSTANT = 123
+      end
+    RUBY
+    action(:lib, "my_library.rb") { code }
+    assert_file "lib/my_library.rb", code.strip_heredoc
   end
 
   def test_rakefile_should_write_date_to_file_in_lib_tasks
-    action :rakefile, 'myapp.rake', 'task run: [:environment]'
-    assert_file 'lib/tasks/myapp.rake', 'task run: [:environment]'
+    action :rakefile, "myapp.rake", "task run: [:environment]"
+    assert_file "lib/tasks/myapp.rake", "task run: [:environment]\n"
+  end
+
+  def test_rakefile_should_write_date_to_file_with_block_in_lib_tasks
+    code = <<-RUBY
+      task rock: :environment do
+        puts "Rockin'"
+      end
+    RUBY
+    action(:rakefile, "myapp.rake") { code }
+    assert_file "lib/tasks/myapp.rake", code.strip_heredoc
   end
 
   def test_initializer_should_write_date_to_file_in_config_initializers
-    action :initializer, 'constants.rb', 'MY_CONSTANT = 42'
-    assert_file 'config/initializers/constants.rb', 'MY_CONSTANT = 42'
+    action :initializer, "constants.rb", "MY_CONSTANT = 42"
+    assert_file "config/initializers/constants.rb", "MY_CONSTANT = 42\n"
+  end
+
+  def test_initializer_should_write_date_to_file_with_block_in_config_initializers
+    code = <<-RUBY
+      MyLib.configure do |config|
+        config.value = 123
+      end
+    RUBY
+    action(:initializer, "constants.rb") { code }
+    assert_file "config/initializers/constants.rb", code.strip_heredoc
   end
 
   def test_generate_should_run_script_generate_with_argument_and_options
-    assert_called_with(generator, :run_ruby_script, ['bin/rails generate model MyModel', verbose: false]) do
-      action :generate, 'model', 'MyModel'
+    assert_called_with(generator, :run_ruby_script, ["bin/rails generate model MyModel", verbose: false]) do
+      action :generate, "model", "MyModel"
     end
   end
 
   def test_rails_should_run_rake_command_with_default_env
     assert_called_with(generator, :run, ["rake log:clear RAILS_ENV=development", verbose: false]) do
       with_rails_env nil do
-        action :rake, 'log:clear'
+        action :rake, "log:clear"
       end
     end
   end
 
   def test_rails_with_env_option_should_run_rake_command_in_env
-    assert_called_with(generator, :run, ['rake log:clear RAILS_ENV=production', verbose: false]) do
-      action :rake, 'log:clear', env: 'production'
+    assert_called_with(generator, :run, ["rake log:clear RAILS_ENV=production", verbose: false]) do
+      action :rake, "log:clear", env: "production"
     end
   end
 
   test "rails command with RAILS_ENV variable should run rake command in env" do
-    assert_called_with(generator, :run, ['rake log:clear RAILS_ENV=production', verbose: false]) do
+    assert_called_with(generator, :run, ["rake log:clear RAILS_ENV=production", verbose: false]) do
       with_rails_env "production" do
-        action :rake, 'log:clear'
+        action :rake, "log:clear"
       end
     end
   end
 
   test "env option should win over RAILS_ENV variable when running rake" do
-    assert_called_with(generator, :run, ['rake log:clear RAILS_ENV=production', verbose: false]) do
+    assert_called_with(generator, :run, ["rake log:clear RAILS_ENV=production", verbose: false]) do
       with_rails_env "staging" do
-        action :rake, 'log:clear', env: 'production'
+        action :rake, "log:clear", env: "production"
       end
     end
   end
@@ -234,7 +303,7 @@ class ActionsTest < Rails::Generators::TestCase
   test "rails command with sudo option should run rake command with sudo" do
     assert_called_with(generator, :run, ["sudo rake log:clear RAILS_ENV=development", verbose: false]) do
       with_rails_env nil do
-        action :rake, 'log:clear', sudo: true
+        action :rake, "log:clear", sudo: true
       end
     end
   end
@@ -242,29 +311,29 @@ class ActionsTest < Rails::Generators::TestCase
   test "rails command should run rails_command with default env" do
     assert_called_with(generator, :run, ["rails log:clear RAILS_ENV=development", verbose: false]) do
       with_rails_env nil do
-        action :rails_command, 'log:clear'
+        action :rails_command, "log:clear"
       end
     end
   end
 
   test "rails command with env option should run rails_command with same env" do
-    assert_called_with(generator, :run, ['rails log:clear RAILS_ENV=production', verbose: false]) do
-      action :rails_command, 'log:clear', env: 'production'
+    assert_called_with(generator, :run, ["rails log:clear RAILS_ENV=production", verbose: false]) do
+      action :rails_command, "log:clear", env: "production"
     end
   end
 
   test "rails command with RAILS_ENV variable should run rails_command in env" do
-    assert_called_with(generator, :run, ['rails log:clear RAILS_ENV=production', verbose: false]) do
+    assert_called_with(generator, :run, ["rails log:clear RAILS_ENV=production", verbose: false]) do
       with_rails_env "production" do
-        action :rails_command, 'log:clear'
+        action :rails_command, "log:clear"
       end
     end
   end
 
   def test_env_option_should_win_over_rails_env_variable_when_running_rails
-    assert_called_with(generator, :run, ['rails log:clear RAILS_ENV=production', verbose: false]) do
+    assert_called_with(generator, :run, ["rails log:clear RAILS_ENV=production", verbose: false]) do
       with_rails_env "staging" do
-        action :rails_command, 'log:clear', env: 'production'
+        action :rails_command, "log:clear", env: "production"
       end
     end
   end
@@ -272,27 +341,30 @@ class ActionsTest < Rails::Generators::TestCase
   test "rails command with sudo option should run rails_command with sudo" do
     assert_called_with(generator, :run, ["sudo rails log:clear RAILS_ENV=development", verbose: false]) do
       with_rails_env nil do
-        action :rails_command, 'log:clear', sudo: true
+        action :rails_command, "log:clear", sudo: true
       end
     end
   end
 
   def test_capify_should_run_the_capify_command
-    assert_called_with(generator, :run, ['capify .', verbose: false]) do
-      action :capify!
+    content = capture(:stderr) do
+      assert_called_with(generator, :run, ["capify .", verbose: false]) do
+        action :capify!
+      end
     end
+    assert_match(/DEPRECATION WARNING: `capify!` is deprecated/, content)
   end
 
   def test_route_should_add_data_to_the_routes_block_in_config_routes
     run_generator
     route_command = "route '/login', controller: 'sessions', action: 'new'"
     action :route, route_command
-    assert_file 'config/routes.rb', /#{Regexp.escape(route_command)}/
+    assert_file "config/routes.rb", /#{Regexp.escape(route_command)}/
   end
 
   def test_route_should_be_idempotent
     run_generator
-    route_path = File.expand_path('config/routes.rb', destination_root)
+    route_path = File.expand_path("config/routes.rb", destination_root)
 
     # runs first time, not asserting
     action :route, "root 'welcome#index'"
@@ -312,8 +384,8 @@ class ActionsTest < Rails::Generators::TestCase
     content = File.read(route_path)
 
     # Remove all of the comments and blank lines from the routes file
-    content.gsub!(/^  \#.*\n/, '')
-    content.gsub!(/^\n/, '')
+    content.gsub!(/^  \#.*\n/, "")
+    content.gsub!(/^\n/, "")
 
     File.open(route_path, "wb") { |file| file.write(content) }
 
@@ -369,10 +441,9 @@ F
     assert_equal("", action(:log, :yes, "YES"))
   end
 
-  protected
+  private
 
     def action(*args, &block)
-      capture(:stdout){ generator.send(*args, &block) }
+      capture(:stdout) { generator.send(*args, &block) }
     end
-
 end
diff --git a/railties/test/generators/api_app_generator_test.rb b/railties/test/generators/api_app_generator_test.rb
index 8e1cd0891a..7791d472d8 100644
--- a/railties/test/generators/api_app_generator_test.rb
+++ b/railties/test/generators/api_app_generator_test.rb
@@ -1,11 +1,13 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/rails/app/app_generator'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/app/app_generator"
 
 class ApiAppGeneratorTest < Rails::Generators::TestCase
   include GeneratorsTestHelper
   tests Rails::Generators::AppGenerator
 
-  arguments [destination_root, '--api']
+  arguments [destination_root, "--api"]
 
   def setup
     Rails.application = TestApp::Application
@@ -33,27 +35,26 @@ class ApiAppGeneratorTest < Rails::Generators::TestCase
   def test_api_modified_files
     run_generator
 
+    assert_file ".gitignore" do |content|
+      assert_no_match(/\/public\/assets/, content)
+    end
+
     assert_file "Gemfile" do |content|
       assert_no_match(/gem 'coffee-rails'/, content)
-      assert_no_match(/gem 'jquery-rails'/, content)
       assert_no_match(/gem 'sass-rails'/, content)
       assert_no_match(/gem 'web-console'/, content)
+      assert_no_match(/gem 'capybara'/, content)
+      assert_no_match(/gem 'selenium-webdriver'/, content)
       assert_match(/# gem 'jbuilder'/, content)
+      assert_match(/# gem 'rack-cors'/, content)
     end
 
-    assert_file "config/application.rb" do |content|
-      assert_match(/config.api_only = true/, content)
-    end
-
-    assert_file "config/initializers/cors.rb"
-
-    assert_file "config/initializers/wrap_parameters.rb"
-
+    assert_file "config/application.rb", /config\.api_only = true/
     assert_file "app/controllers/application_controller.rb", /ActionController::API/
   end
 
   def test_generator_if_skip_action_cable_is_given
-    run_generator [destination_root, "--skip-action-cable"]
+    run_generator [destination_root, "--api", "--skip-action-cable"]
     assert_file "config/application.rb", /#\s+require\s+["']action_cable\/engine["']/
     assert_no_file "config/cable.yml"
     assert_no_file "app/channels"
@@ -62,49 +63,102 @@ class ApiAppGeneratorTest < Rails::Generators::TestCase
     end
   end
 
-  private
+  def test_app_update_does_not_generate_unnecessary_config_files
+    run_generator
+
+    generator = Rails::Generators::AppGenerator.new ["rails"],
+      { api: true, update: true }, { destination_root: destination_root, shell: @shell }
+    quietly { generator.send(:update_config_files) }
 
-  def default_files
-    files = %W(
-      .gitignore
-      Gemfile
-      Rakefile
-      config.ru
-      app/controllers
-      app/mailers
-      app/models
-      app/views/layouts/mailer.html.erb
-      app/views/layouts/mailer.text.erb
-      config/environments
-      config/initializers
-      config/locales
-      db
-      lib
-      lib/tasks
-      log
-      test/fixtures
-      test/controllers
-      test/integration
-      test/models
-      tmp
-      vendor
-    )
-    files.concat %w(bin/bundle bin/rails bin/rake)
-    files
+    assert_no_file "config/initializers/cookies_serializer.rb"
+    assert_no_file "config/initializers/assets.rb"
   end
 
-  def skipped_files
-    %w(app/assets
-       app/helpers
-       app/views/layouts/application.html.erb
-       config/initializers/assets.rb
-       config/initializers/cookies_serializer.rb
-       config/initializers/session_store.rb
-       config/initializers/request_forgery_protection.rb
-       config/initializers/per_form_csrf_tokens.rb
-       lib/assets
-       vendor/assets
-       test/helpers
-       tmp/cache/assets)
+  def test_app_update_does_not_generate_unnecessary_bin_files
+    run_generator
+
+    generator = Rails::Generators::AppGenerator.new ["rails"],
+      { api: true, update: true }, { destination_root: destination_root, shell: @shell }
+    quietly { generator.send(:update_bin_files) }
+
+    assert_no_file "bin/yarn"
   end
+
+  private
+
+    def default_files
+      %w(.gitignore
+        .ruby-version
+        README.md
+        Gemfile
+        Rakefile
+        config.ru
+        app/channels
+        app/controllers
+        app/mailers
+        app/models
+        app/views/layouts
+        app/views/layouts/mailer.html.erb
+        app/views/layouts/mailer.text.erb
+        bin/bundle
+        bin/rails
+        bin/rake
+        bin/setup
+        bin/update
+        config/application.rb
+        config/boot.rb
+        config/cable.yml
+        config/environment.rb
+        config/environments
+        config/environments/development.rb
+        config/environments/production.rb
+        config/environments/test.rb
+        config/initializers
+        config/initializers/application_controller_renderer.rb
+        config/initializers/backtrace_silencers.rb
+        config/initializers/cors.rb
+        config/initializers/filter_parameter_logging.rb
+        config/initializers/inflections.rb
+        config/initializers/mime_types.rb
+        config/initializers/wrap_parameters.rb
+        config/locales
+        config/locales/en.yml
+        config/puma.rb
+        config/routes.rb
+        config/credentials.yml.enc
+        config/spring.rb
+        config/storage.yml
+        db
+        db/seeds.rb
+        lib
+        lib/tasks
+        log
+        test/fixtures
+        test/controllers
+        test/integration
+        test/models
+        tmp
+        vendor
+      )
+    end
+
+    def skipped_files
+      %w(app/assets
+         app/helpers
+         app/views/layouts/application.html.erb
+         bin/yarn
+         config/initializers/assets.rb
+         config/initializers/cookies_serializer.rb
+         lib/assets
+         test/helpers
+         tmp/cache/assets
+         public/404.html
+         public/422.html
+         public/500.html
+         public/apple-touch-icon-precomposed.png
+         public/apple-touch-icon.png
+         public/favicon.ico
+         package.json
+      )
+    end
 end
diff --git a/railties/test/generators/app_generator_test.rb b/railties/test/generators/app_generator_test.rb
index 2d9867fa9d..160ad1a928 100644
--- a/railties/test/generators/app_generator_test.rb
+++ b/railties/test/generators/app_generator_test.rb
@@ -1,39 +1,81 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/rails/app/app_generator'
-require 'generators/shared_generator_tests'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/app/app_generator"
+require "generators/shared_generator_tests"
 
 DEFAULT_APP_FILES = %w(
   .gitignore
+  .ruby-version
   README.md
   Gemfile
   Rakefile
   config.ru
+  app/assets/config/manifest.js
+  app/assets/images
   app/assets/javascripts
+  app/assets/javascripts/application.js
+  app/assets/javascripts/cable.js
+  app/assets/javascripts/channels
   app/assets/stylesheets
-  app/assets/images
+  app/assets/stylesheets/application.css
+  app/channels/application_cable/channel.rb
+  app/channels/application_cable/connection.rb
   app/controllers
+  app/controllers/application_controller.rb
   app/controllers/concerns
   app/helpers
+  app/helpers/application_helper.rb
   app/mailers
+  app/mailers/application_mailer.rb
   app/models
+  app/models/application_record.rb
   app/models/concerns
   app/jobs
+  app/jobs/application_job.rb
   app/views/layouts
+  app/views/layouts/application.html.erb
+  app/views/layouts/mailer.html.erb
+  app/views/layouts/mailer.text.erb
   bin/bundle
   bin/rails
   bin/rake
   bin/setup
+  bin/update
+  bin/yarn
+  config/application.rb
+  config/boot.rb
+  config/cable.yml
+  config/environment.rb
   config/environments
+  config/environments/development.rb
+  config/environments/production.rb
+  config/environments/test.rb
   config/initializers
+  config/initializers/application_controller_renderer.rb
+  config/initializers/assets.rb
+  config/initializers/backtrace_silencers.rb
+  config/initializers/cookies_serializer.rb
+  config/initializers/filter_parameter_logging.rb
+  config/initializers/inflections.rb
+  config/initializers/mime_types.rb
+  config/initializers/wrap_parameters.rb
   config/locales
-  config/cable.yml
+  config/locales/en.yml
   config/puma.rb
+  config/routes.rb
+  config/credentials.yml.enc
   config/spring.rb
+  config/storage.yml
   db
+  db/seeds.rb
   lib
   lib/tasks
   lib/assets
   log
+  package.json
+  public
+  test/application_system_test_case.rb
   test/test_helper.rb
   test/fixtures
   test/fixtures/files
@@ -42,10 +84,8 @@ DEFAULT_APP_FILES = %w(
   test/helpers
   test/mailers
   test/integration
+  test/system
   vendor
-  vendor/assets
-  vendor/assets/stylesheets
-  vendor/assets/javascripts
   tmp
   tmp/cache
   tmp/cache/assets
@@ -77,7 +117,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_invalid_application_name_raises_an_error
-    content = capture(:stderr){ run_generator [File.join(destination_root, "43-things")] }
+    content = capture(:stderr) { run_generator [File.join(destination_root, "43-things")] }
     assert_equal "Invalid application name 43-things. Please give a name which does not start with numbers.\n", content
   end
 
@@ -88,12 +128,12 @@ class AppGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_application_new_exits_with_non_zero_code_on_invalid_application_name
-    quietly { system 'rails new test --no-rc' }
+    quietly { system "rails new test --no-rc" }
     assert_equal false, $?.success?
   end
 
   def test_application_new_exits_with_message_and_non_zero_code_when_generating_inside_existing_rails_directory
-    app_root = File.join(destination_root, 'myfirstapp')
+    app_root = File.join(destination_root, "myfirstapp")
     run_generator [app_root]
     output = nil
     Dir.chdir(app_root) do
@@ -104,7 +144,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_application_new_show_help_message_inside_existing_rails_directory
-    app_root = File.join(destination_root, 'myfirstapp')
+    app_root = File.join(destination_root, "myfirstapp")
     run_generator [app_root]
     output = Dir.chdir(app_root) do
       `rails new --help`
@@ -131,20 +171,18 @@ class AppGeneratorTest < Rails::Generators::TestCase
         generator.send(:app_const)
         quietly { generator.send(:update_config_files) }
         assert_file "myapp_moved/config/environment.rb", /Rails\.application\.initialize!/
-        assert_file "myapp_moved/config/initializers/session_store.rb", /_myapp_session/
       end
     end
   end
 
-  def test_rails_update_generates_correct_session_key
-    app_root = File.join(destination_root, 'myapp')
+  def test_app_update_generates_correct_session_key
+    app_root = File.join(destination_root, "myapp")
     run_generator [app_root]
 
     stub_rails_application(app_root) do
       generator = Rails::Generators::AppGenerator.new ["rails"], [], destination_root: app_root, shell: @shell
       generator.send(:app_const)
       quietly { generator.send(:update_config_files) }
-      assert_file "myapp/config/initializers/session_store.rb", /_myapp_session/
     end
   end
 
@@ -157,51 +195,39 @@ class AppGeneratorTest < Rails::Generators::TestCase
   def test_new_application_not_include_api_initializers
     run_generator
 
-    assert_no_file 'config/initializers/cors.rb'
+    assert_no_file "config/initializers/cors.rb"
   end
 
-  def test_rails_update_keep_the_cookie_serializer_if_it_is_already_configured
-    app_root = File.join(destination_root, 'myapp')
-    run_generator [app_root]
-
-    stub_rails_application(app_root) do
-      generator = Rails::Generators::AppGenerator.new ["rails"], [], destination_root: app_root, shell: @shell
-      generator.send(:app_const)
-      quietly { generator.send(:update_config_files) }
-      assert_file("#{app_root}/config/initializers/cookies_serializer.rb", /Rails\.application\.config\.action_dispatch\.cookies_serializer = :json/)
-    end
+  def test_new_application_doesnt_need_defaults
+    assert_no_file "config/initializers/new_framework_defaults_5_2.rb"
   end
 
-  def test_rails_update_does_not_create_callback_terminator_initializer
-    app_root = File.join(destination_root, 'myapp')
+  def test_new_application_load_defaults
+    app_root = File.join(destination_root, "myfirstapp")
     run_generator [app_root]
+    output = nil
 
-    FileUtils.rm("#{app_root}/config/initializers/callback_terminator.rb")
-
-    stub_rails_application(app_root) do
-      generator = Rails::Generators::AppGenerator.new ["rails"], [], destination_root: app_root, shell: @shell
-      generator.send(:app_const)
-      quietly { generator.send(:update_config_files) }
-      assert_no_file "#{app_root}/config/initializers/callback_terminator.rb"
+    Dir.chdir(app_root) do
+      output = `./bin/rails r "puts Rails.application.config.assets.unknown_asset_fallback"`
     end
+
+    assert_equal "false\n", output
   end
 
-  def test_rails_update_does_not_remove_callback_terminator_initializer_if_already_present
-    app_root = File.join(destination_root, 'myapp')
+  def test_app_update_keep_the_cookie_serializer_if_it_is_already_configured
+    app_root = File.join(destination_root, "myapp")
     run_generator [app_root]
 
-    FileUtils.touch("#{app_root}/config/initializers/callback_terminator.rb")
-
     stub_rails_application(app_root) do
       generator = Rails::Generators::AppGenerator.new ["rails"], [], destination_root: app_root, shell: @shell
       generator.send(:app_const)
       quietly { generator.send(:update_config_files) }
-      assert_file "#{app_root}/config/initializers/callback_terminator.rb"
+      assert_file("#{app_root}/config/initializers/cookies_serializer.rb", /Rails\.application\.config\.action_dispatch\.cookies_serializer = :json/)
     end
   end
 
-  def test_rails_update_set_the_cookie_serializer_to_marshal_if_it_is_not_already_configured
-    app_root = File.join(destination_root, 'myapp')
+  def test_app_update_set_the_cookie_serializer_to_marshal_if_it_is_not_already_configured
+    app_root = File.join(destination_root, "myapp")
     run_generator [app_root]
 
     FileUtils.rm("#{app_root}/config/initializers/cookies_serializer.rb")
@@ -215,99 +241,58 @@ class AppGeneratorTest < Rails::Generators::TestCase
     end
   end
 
-  def test_rails_update_dont_set_file_watcher
-    app_root = File.join(destination_root, 'myapp')
-    run_generator [app_root]
-
-    stub_rails_application(app_root) do
-      generator = Rails::Generators::AppGenerator.new ["rails"], [], destination_root: app_root, shell: @shell
-      generator.send(:app_const)
-      quietly { generator.send(:update_config_files) }
-      assert_file "#{app_root}/config/environments/development.rb" do |content|
-        assert_match(/# config.file_watcher/, content)
-      end
-    end
-  end
-
-  def test_rails_update_does_not_create_active_record_belongs_to_required_by_default
-    app_root = File.join(destination_root, 'myapp')
+  def test_app_update_create_new_framework_defaults
+    app_root = File.join(destination_root, "myapp")
     run_generator [app_root]
 
-    FileUtils.rm("#{app_root}/config/initializers/active_record_belongs_to_required_by_default.rb")
+    assert_no_file "#{app_root}/config/initializers/new_framework_defaults_5_2.rb"
 
     stub_rails_application(app_root) do
-      generator = Rails::Generators::AppGenerator.new ["rails"], [], destination_root: app_root, shell: @shell
+      generator = Rails::Generators::AppGenerator.new ["rails"], { update: true }, { destination_root: app_root, shell: @shell }
       generator.send(:app_const)
       quietly { generator.send(:update_config_files) }
-      assert_no_file "#{app_root}/config/initializers/active_record_belongs_to_required_by_default.rb"
-    end
-  end
-
-  def test_rails_update_does_not_remove_active_record_belongs_to_required_by_default_if_already_present
-    app_root = File.join(destination_root, 'myapp')
-    run_generator [app_root]
 
-    FileUtils.touch("#{app_root}/config/initializers/active_record_belongs_to_required_by_default.rb")
-
-    stub_rails_application(app_root) do
-      generator = Rails::Generators::AppGenerator.new ["rails"], [], destination_root: app_root, shell: @shell
-      generator.send(:app_const)
-      quietly { generator.send(:update_config_files) }
-      assert_file "#{app_root}/config/initializers/active_record_belongs_to_required_by_default.rb"
+      assert_file "#{app_root}/config/initializers/new_framework_defaults_5_2.rb"
     end
   end
 
-  def test_rails_update_does_not_create_ssl_options_by_default
-    app_root = File.join(destination_root, 'myapp')
+  def test_app_update_does_not_create_rack_cors
+    app_root = File.join(destination_root, "myapp")
     run_generator [app_root]
 
-    FileUtils.rm("#{app_root}/config/initializers/ssl_options.rb")
-
     stub_rails_application(app_root) do
       generator = Rails::Generators::AppGenerator.new ["rails"], [], destination_root: app_root, shell: @shell
       generator.send(:app_const)
       quietly { generator.send(:update_config_files) }
-      assert_no_file "#{app_root}/config/initializers/ssl_options.rb"
+      assert_no_file "#{app_root}/config/initializers/cors.rb"
     end
   end
 
-  def test_rails_update_does_not_remove_ssl_options_if_already_present
-    app_root = File.join(destination_root, 'myapp')
+  def test_app_update_does_not_remove_rack_cors_if_already_present
+    app_root = File.join(destination_root, "myapp")
     run_generator [app_root]
 
-    FileUtils.touch("#{app_root}/config/initializers/ssl_options.rb")
+    FileUtils.touch("#{app_root}/config/initializers/cors.rb")
 
     stub_rails_application(app_root) do
       generator = Rails::Generators::AppGenerator.new ["rails"], [], destination_root: app_root, shell: @shell
       generator.send(:app_const)
       quietly { generator.send(:update_config_files) }
-      assert_file "#{app_root}/config/initializers/ssl_options.rb"
+      assert_file "#{app_root}/config/initializers/cors.rb"
     end
   end
 
-  def test_rails_update_does_not_create_rack_cors
-    app_root = File.join(destination_root, 'myapp')
-    run_generator [app_root]
+  def test_app_update_does_not_generate_action_cable_contents_when_skip_action_cable_is_given
+    app_root = File.join(destination_root, "myapp")
+    run_generator [app_root, "--skip-action-cable"]
 
-    stub_rails_application(app_root) do
-      generator = Rails::Generators::AppGenerator.new ["rails"], [], destination_root: app_root, shell: @shell
-      generator.send(:app_const)
-      quietly { generator.send(:update_config_files) }
-      assert_no_file "#{app_root}/config/initializers/cors.rb"
+    FileUtils.cd(app_root) do
+      quietly { system("bin/rails app:update") }
     end
-  end
 
-  def test_rails_update_does_not_remove_rack_cors_if_already_present
-    app_root = File.join(destination_root, 'myapp')
-    run_generator [app_root]
-
-    FileUtils.touch("#{app_root}/config/initializers/cors.rb")
-
-    stub_rails_application(app_root) do
-      generator = Rails::Generators::AppGenerator.new ["rails"], [], destination_root: app_root, shell: @shell
-      generator.send(:app_const)
-      quietly { generator.send(:update_config_files) }
-      assert_file "#{app_root}/config/initializers/cors.rb"
+    assert_no_file "#{app_root}/config/cable.yml"
+    assert_file "#{app_root}/config/environments/production.rb" do |content|
+      assert_no_match(/config\.action_cable/, content)
     end
   end
 
@@ -319,7 +304,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
   def test_gemfile_has_no_whitespace_errors
     run_generator
     absolute = File.expand_path("Gemfile", destination_root)
-    File.open(absolute, 'r') do |f|
+    File.open(absolute, "r") do |f|
       f.each_line do |line|
         assert_no_match %r{/^[ \t]+$/}, line
       end
@@ -394,23 +379,9 @@ class AppGeneratorTest < Rails::Generators::TestCase
     end
   end
 
-  def test_generator_without_skips
-    run_generator
-    assert_file "config/application.rb", /\s+require\s+["']rails\/all["']/
-    assert_file "config/environments/development.rb" do |content|
-      assert_match(/config\.action_mailer\.raise_delivery_errors = false/, content)
-    end
-    assert_file "config/environments/test.rb" do |content|
-      assert_match(/config\.action_mailer\.delivery_method = :test/, content)
-    end
-    assert_file "config/environments/production.rb" do |content|
-      assert_match(/# config\.action_mailer\.raise_delivery_errors = false/, content)
-    end
-  end
-
   def test_generator_defaults_to_puma_version
     run_generator [destination_root]
-    assert_gem "puma", "'~> 3.0'"
+    assert_gem "puma", "'~> 3.7'"
   end
 
   def test_generator_if_skip_puma_is_given
@@ -421,108 +392,78 @@ class AppGeneratorTest < Rails::Generators::TestCase
     end
   end
 
-  def test_generator_if_skip_active_record_is_given
-    run_generator [destination_root, "--skip-active-record"]
-    assert_no_file "config/database.yml"
-    assert_no_file "config/initializers/active_record_belongs_to_required_by_default.rb"
-    assert_no_file "app/models/application_record.rb"
-    assert_file "config/application.rb", /#\s+require\s+["']active_record\/railtie["']/
-    assert_file "test/test_helper.rb" do |helper_content|
-      assert_no_match(/fixtures :all/, helper_content)
-    end
-  end
+  def test_generator_has_assets_gems
+    run_generator
 
-  def test_generator_if_skip_action_mailer_is_given
-    run_generator [destination_root, "--skip-action-mailer"]
-    assert_file "config/application.rb", /#\s+require\s+["']action_mailer\/railtie["']/
-    assert_file "config/environments/development.rb" do |content|
-      assert_no_match(/config\.action_mailer/, content)
-    end
-    assert_file "config/environments/test.rb" do |content|
-      assert_no_match(/config\.action_mailer/, content)
-    end
-    assert_file "config/environments/production.rb" do |content|
-      assert_no_match(/config\.action_mailer/, content)
-    end
+    assert_gem "sass-rails"
+    assert_gem "uglifier"
   end
 
-  def test_generator_has_assets_gems
+  def test_action_cable_redis_gems
     run_generator
-
-    assert_gem 'sass-rails'
-    assert_gem 'uglifier'
+    assert_file "Gemfile", /^# gem 'redis'/
   end
 
-  def test_generator_if_skip_sprockets_is_given
-    run_generator [destination_root, "--skip-sprockets"]
-    assert_no_file "config/initializers/assets.rb"
-    assert_file "config/application.rb" do |content|
-      assert_match(/#\s+require\s+["']sprockets\/railtie["']/, content)
-    end
+  def test_generator_if_skip_test_is_given
+    run_generator [destination_root, "--skip-test"]
+
+    assert_file "config/application.rb", /#\s+require\s+["']rails\/test_unit\/railtie["']/
+
     assert_file "Gemfile" do |content|
-      assert_no_match(/jquery-rails/, content)
-      assert_no_match(/sass-rails/, content)
-      assert_no_match(/uglifier/, content)
-      assert_no_match(/coffee-rails/, content)
-    end
-    assert_file "config/environments/development.rb" do |content|
-      assert_no_match(/config\.assets\.debug = true/, content)
-    end
-    assert_file "config/environments/production.rb" do |content|
-      assert_no_match(/config\.assets\.digest = true/, content)
-      assert_no_match(/config\.assets\.js_compressor = :uglifier/, content)
-      assert_no_match(/config\.assets\.css_compressor = :sass/, content)
+      assert_no_match(/capybara/, content)
+      assert_no_match(/selenium-webdriver/, content)
+      assert_no_match(/chromedriver-helper/, content)
     end
+
+    assert_no_directory("test")
   end
 
-  def test_generator_if_skip_action_cable_is_given
-    run_generator [destination_root, "--skip-action-cable"]
-    assert_file "config/application.rb", /#\s+require\s+["']action_cable\/engine["']/
-    assert_no_file "config/cable.yml"
-    assert_no_file "app/assets/javascripts/cable.js"
-    assert_no_file "app/channels"
+  def test_generator_if_skip_system_test_is_given
+    run_generator [destination_root, "--skip-system-test"]
     assert_file "Gemfile" do |content|
-      assert_no_match(/redis/, content)
+      assert_no_match(/capybara/, content)
+      assert_no_match(/selenium-webdriver/, content)
+      assert_no_match(/chromedriver-helper/, content)
     end
+
+    assert_directory("test")
+
+    assert_no_directory("test/system")
   end
 
-  def test_action_cable_redis_gems
-    run_generator
-    assert_file "Gemfile", /^# gem 'redis'/
+  def test_does_not_generate_system_test_files_if_skip_system_test_is_given
+    run_generator [destination_root, "--skip-system-test"]
+
+    Dir.chdir(destination_root) do
+      quietly { `./bin/rails g scaffold User` }
+
+      assert_no_file("test/application_system_test_case.rb")
+      assert_no_file("test/system/users_test.rb")
+    end
   end
 
   def test_inclusion_of_javascript_runtime
     run_generator
     if defined?(JRUBY_VERSION)
       assert_gem "therubyrhino"
+    elsif RUBY_PLATFORM =~ /mingw|mswin/
+      assert_gem "duktape"
     else
-      assert_file "Gemfile", /# gem 'therubyracer', platforms: :ruby/
+      assert_file "Gemfile", /# gem 'mini_racer', platforms: :ruby/
     end
   end
 
-  def test_jquery_is_the_default_javascript_library
+  def test_rails_ujs_is_the_default_ujs_library
     run_generator
     assert_file "app/assets/javascripts/application.js" do |contents|
-      assert_match %r{^//= require jquery}, contents
-      assert_match %r{^//= require jquery_ujs}, contents
+      assert_match %r{^//= require rails-ujs}, contents
     end
-    assert_gem "jquery-rails"
-  end
-
-  def test_other_javascript_libraries
-    run_generator [destination_root, '-j', 'prototype']
-    assert_file "app/assets/javascripts/application.js" do |contents|
-      assert_match %r{^//= require prototype}, contents
-      assert_match %r{^//= require prototype_ujs}, contents
-    end
-    assert_gem "prototype-rails"
   end
 
   def test_javascript_is_skipped_if_required
     run_generator [destination_root, "--skip-javascript"]
 
     assert_no_file "app/assets/javascripts"
-    assert_no_file "vendor/assets/javascripts"
 
     assert_file "app/views/layouts/application.html.erb" do |contents|
       assert_match(/stylesheet_link_tag\s+'application', media: 'all' %>/, contents)
@@ -531,13 +472,26 @@ class AppGeneratorTest < Rails::Generators::TestCase
 
     assert_file "Gemfile" do |content|
       assert_no_match(/coffee-rails/, content)
-      assert_no_match(/jquery-rails/, content)
+      assert_no_match(/uglifier/, content)
+    end
+
+    assert_file "config/environments/production.rb" do |content|
+      assert_no_match(/config\.assets\.js_compressor = :uglifier/, content)
+    end
+  end
+
+  def test_coffeescript_is_skipped_if_required
+    run_generator [destination_root, "--skip-coffee"]
+
+    assert_file "Gemfile" do |content|
+      assert_no_match(/coffee-rails/, content)
+      assert_match(/uglifier/, content)
     end
   end
 
   def test_inclusion_of_jbuilder
     run_generator
-    assert_gem 'jbuilder'
+    assert_gem "jbuilder"
   end
 
   def test_inclusion_of_a_debugger
@@ -547,13 +501,13 @@ class AppGeneratorTest < Rails::Generators::TestCase
         assert_no_match(/byebug/, content)
       end
     else
-      assert_gem 'byebug'
+      assert_gem "byebug"
     end
   end
 
   def test_inclusion_of_listen_related_configuration_by_default
     run_generator
-    if RbConfig::CONFIG['host_os'] =~ /darwin|linux/
+    if RbConfig::CONFIG["host_os"] =~ /darwin|linux/
       assert_listen_related_configuration
     else
       assert_no_listen_related_configuration
@@ -561,17 +515,17 @@ class AppGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_non_inclusion_of_listen_related_configuration_if_skip_listen
-    run_generator [destination_root, '--skip-listen']
+    run_generator [destination_root, "--skip-listen"]
     assert_no_listen_related_configuration
   end
 
   def test_evented_file_update_checker_config
     run_generator
-    assert_file 'config/environments/development.rb' do |content|
-      if RbConfig::CONFIG['host_os'] =~ /darwin|linux/
-        assert_match(/^\s*config.file_watcher = ActiveSupport::EventedFileUpdateChecker/, content)
+    assert_file "config/environments/development.rb" do |content|
+      if RbConfig::CONFIG["host_os"] =~ /darwin|linux/
+        assert_match(/^\s*config\.file_watcher = ActiveSupport::EventedFileUpdateChecker/, content)
       else
-        assert_match(/^\s*# config.file_watcher = ActiveSupport::EventedFileUpdateChecker/, content)
+        assert_match(/^\s*# config\.file_watcher = ActiveSupport::EventedFileUpdateChecker/, content)
       end
     end
   end
@@ -598,47 +552,33 @@ class AppGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_file_is_added_for_backwards_compatibility
-    action :file, 'lib/test_file.rb', 'heres test data'
-    assert_file 'lib/test_file.rb', 'heres test data'
-  end
-
-  def test_tests_are_removed_from_frameworks_if_skip_test_is_given
-    run_generator [destination_root, "--skip-test"]
-    assert_file "config/application.rb", /#\s+require\s+["']rails\/test_unit\/railtie["']/
-  end
-
-  def test_no_active_record_or_tests_if_skips_given
-    run_generator [destination_root, "--skip-test", "--skip-active-record"]
-    assert_file "config/application.rb", /#\s+require\s+["']rails\/test_unit\/railtie["']/
-    assert_file "config/application.rb", /#\s+require\s+["']active_record\/railtie["']/
-    assert_file "config/application.rb", /\s+require\s+["']active_job\/railtie["']/
-  end
-
-  def test_new_hash_style
-    run_generator
-    assert_file "config/initializers/session_store.rb" do |file|
-      assert_match(/config.session_store :cookie_store, key: '_.+_session'/, file)
-    end
+    action :file, "lib/test_file.rb", "heres test data"
+    assert_file "lib/test_file.rb", "heres test data"
   end
 
   def test_pretend_option
     output = run_generator [File.join(destination_root, "myapp"), "--pretend"]
     assert_no_match(/run  bundle install/, output)
+    assert_no_match(/run  git init/, output)
+  end
+
+  def test_quiet_option
+    output = run_generator [File.join(destination_root, "myapp"), "--quiet"]
+    assert_empty output
   end
 
   def test_application_name_with_spaces
     path = File.join(destination_root, "foo bar")
 
     # This also applies to MySQL apps but not with SQLite
-    run_generator [path, "-d", 'postgresql']
+    run_generator [path, "-d", "postgresql"]
 
     assert_file "foo bar/config/database.yml", /database: foo_bar_development/
-    assert_file "foo bar/config/initializers/session_store.rb", /key: '_foo_bar/
   end
 
   def test_web_console
     run_generator
-    assert_gem 'web-console'
+    assert_gem "web-console"
   end
 
   def test_web_console_with_dev_option
@@ -646,7 +586,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
 
     assert_file "Gemfile" do |content|
       assert_match(/gem 'web-console',\s+github: 'rails\/web-console'/, content)
-      assert_no_match(/\Agem 'web-console'\z/, content)
+      assert_no_match(/\Agem 'web-console', '>= 3\.3\.0'\z/, content)
     end
   end
 
@@ -655,13 +595,28 @@ class AppGeneratorTest < Rails::Generators::TestCase
 
     assert_file "Gemfile" do |content|
       assert_match(/gem 'web-console',\s+github: 'rails\/web-console'/, content)
-      assert_no_match(/\Agem 'web-console'\z/, content)
+      assert_no_match(/\Agem 'web-console', '>= 3\.3\.0'\z/, content)
     end
   end
 
+  def test_generation_runs_bundle_install
+    assert_generates_with_bundler
+  end
+
+  def test_dev_option
+    assert_generates_with_bundler dev: true
+    rails_path = File.expand_path("../../..", Rails.root)
+    assert_file "Gemfile", /^gem\s+["']rails["'],\s+path:\s+["']#{Regexp.escape(rails_path)}["']$/
+  end
+
+  def test_edge_option
+    assert_generates_with_bundler edge: true
+    assert_file "Gemfile", %r{^gem\s+["']rails["'],\s+github:\s+["']#{Regexp.escape("rails/rails")}["']$}
+  end
+
   def test_spring
     run_generator
-    assert_gem 'spring'
+    assert_gem "spring"
   end
 
   def test_spring_binstubs
@@ -670,9 +625,9 @@ class AppGeneratorTest < Rails::Generators::TestCase
       @binstub_called ||= 0
 
       case command
-      when 'install'
+      when "install"
         # Called when running bundle, we just want to stub it so nothing to do here.
-      when 'exec spring binstub --all'
+      when "exec spring binstub --all"
         @binstub_called += 1
         assert_equal 1, @binstub_called, "exec spring binstub --all expected to be called once, but was called #{@install_called} times."
       end
@@ -697,7 +652,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
   def test_skip_spring
     run_generator [destination_root, "--skip-spring"]
 
-    assert_no_file 'config/spring.rb'
+    assert_no_file "config/spring.rb"
     assert_file "Gemfile" do |content|
       assert_no_match(/spring/, content)
     end
@@ -725,28 +680,20 @@ class AppGeneratorTest < Rails::Generators::TestCase
     end
   end
 
-  def test_gitignore_when_sqlite3
+  def test_inclusion_of_ruby_version
     run_generator
 
-    assert_file '.gitignore' do |content|
-      assert_match(/sqlite3/, content)
+    assert_file "Gemfile" do |content|
+      assert_match(/ruby '#{RUBY_VERSION}'/, content)
     end
-  end
-
-  def test_gitignore_when_no_active_record
-    run_generator [destination_root, '--skip-active-record']
-
-    assert_file '.gitignore' do |content|
-      assert_no_match(/sqlite/i, content)
+    assert_file ".ruby-version" do |content|
+      assert_match(/#{RUBY_VERSION}/, content)
     end
   end
 
-  def test_gitignore_when_non_sqlite3_db
-    run_generator([destination_root, "-d", "mysql"])
-
-    assert_file '.gitignore' do |content|
-      assert_no_match(/sqlite/i, content)
-    end
+  def test_version_control_initializes_git_repo
+    run_generator [destination_root]
+    assert_directory ".git"
   end
 
   def test_create_keeps
@@ -766,7 +713,6 @@ class AppGeneratorTest < Rails::Generators::TestCase
       test/helpers
       test/integration
       tmp
-      vendor/assets/stylesheets
     )
     folders_with_keep.each do |folder|
       assert_file("#{folder}/.keep")
@@ -775,7 +721,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
 
   def test_psych_gem
     run_generator
-    gem_regex = /gem 'psych',\s+'~> 2.0',\s+platforms: :rbx/
+    gem_regex = /gem 'psych',\s+'~> 2\.0',\s+platforms: :rbx/
 
     assert_file "Gemfile" do |content|
       if defined?(Rubinius)
@@ -787,18 +733,18 @@ class AppGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_after_bundle_callback
-    path = 'http://example.org/rails_template'
-    template = %{ after_bundle { run 'echo ran after_bundle' } }
+    path = "http://example.org/rails_template"
+    template = %{ after_bundle { run 'echo ran after_bundle' } }.dup
     template.instance_eval "def read; self; end" # Make the string respond to read
 
     check_open = -> *args do
-      assert_equal [ path, 'Accept' => 'application/x-thor-template' ], args
+      assert_equal [ path, "Accept" => "application/x-thor-template" ], args
       template
     end
 
-    sequence = ['install', 'exec spring binstub --all', 'echo ran after_bundle']
-      @sequence_step ||= 0
-    ensure_bundler_first = -> command do
+    sequence = ["git init", "install", "exec spring binstub --all", "echo ran after_bundle"]
+    @sequence_step ||= 0
+    ensure_bundler_first = -> command, options = nil do
       assert_equal sequence[@sequence_step], command, "commands should be called in sequence #{sequence}"
       @sequence_step += 1
     end
@@ -811,46 +757,72 @@ class AppGeneratorTest < Rails::Generators::TestCase
       end
     end
 
-    assert_equal 3, @sequence_step
+    assert_equal 4, @sequence_step
   end
 
-  protected
+  def test_system_tests_directory_generated
+    run_generator
 
-  def stub_rails_application(root)
-    Rails.application.config.root = root
-    Rails.application.class.stub(:name, "Myapp") do
-      yield
-    end
+    assert_file("test/system/.keep")
+    assert_directory("test/system")
   end
 
-  def action(*args, &block)
-    capture(:stdout) { generator.send(*args, &block) }
-  end
+  private
+    def stub_rails_application(root)
+      Rails.application.config.root = root
+      Rails.application.class.stub(:name, "Myapp") do
+        yield
+      end
+    end
 
-  def assert_gem(gem, constraint = nil)
-    if constraint
-      assert_file "Gemfile", /^\s*gem\s+["']#{gem}["'], #{constraint}$*/
-    else
-      assert_file "Gemfile", /^\s*gem\s+["']#{gem}["']$*/
+    def action(*args, &block)
+      capture(:stdout) { generator.send(*args, &block) }
     end
-  end
 
-  def assert_listen_related_configuration
-    assert_gem 'listen'
-    assert_gem 'spring-watcher-listen'
+    def assert_gem(gem, constraint = nil)
+      if constraint
+        assert_file "Gemfile", /^\s*gem\s+["']#{gem}["'], #{constraint}$*/
+      else
+        assert_file "Gemfile", /^\s*gem\s+["']#{gem}["']$*/
+      end
+    end
+
+    def assert_listen_related_configuration
+      assert_gem "listen"
+      assert_gem "spring-watcher-listen"
 
-    assert_file 'config/environments/development.rb' do |content|
-      assert_match(/^\s*config.file_watcher = ActiveSupport::EventedFileUpdateChecker/, content)
+      assert_file "config/environments/development.rb" do |content|
+        assert_match(/^\s*config\.file_watcher = ActiveSupport::EventedFileUpdateChecker/, content)
+      end
     end
-  end
 
-  def assert_no_listen_related_configuration
-    assert_file 'Gemfile' do |content|
-      assert_no_match(/listen/, content)
+    def assert_no_listen_related_configuration
+      assert_file "Gemfile" do |content|
+        assert_no_match(/listen/, content)
+      end
+
+      assert_file "config/environments/development.rb" do |content|
+        assert_match(/^\s*# config\.file_watcher = ActiveSupport::EventedFileUpdateChecker/, content)
+      end
     end
 
-    assert_file 'config/environments/development.rb' do |content|
-      assert_match(/^\s*# config.file_watcher = ActiveSupport::EventedFileUpdateChecker/, content)
+    def assert_generates_with_bundler(options = {})
+      generator([destination_root], options)
+
+      command_check = -> command do
+        @install_called ||= 0
+
+        case command
+        when "install"
+          @install_called += 1
+          assert_equal 1, @install_called, "install expected to be called once, but was called #{@install_called} times"
+        when "exec spring binstub --all"
+          # Called when running tests with spring, let through unscathed.
+        end
+      end
+
+      generator.stub :bundle_command, command_check do
+        quietly { generator.invoke_all }
+      end
     end
-  end
 end
diff --git a/railties/test/generators/application_record_generator_test.rb b/railties/test/generators/application_record_generator_test.rb
new file mode 100644
index 0000000000..2c0aa7211b
--- /dev/null
+++ b/railties/test/generators/application_record_generator_test.rb
@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/application_record/application_record_generator"
+
+class ApplicationRecordGeneratorTest < Rails::Generators::TestCase
+  include GeneratorsTestHelper
+
+  def test_application_record_skeleton_is_created
+    run_generator
+    assert_file "app/models/application_record.rb" do |record|
+      assert_match(/class ApplicationRecord < ActiveRecord::Base/, record)
+      assert_match(/self\.abstract_class = true/, record)
+    end
+  end
+end
diff --git a/railties/test/generators/argv_scrubber_test.rb b/railties/test/generators/argv_scrubber_test.rb
index 31e07bc8da..9ef61dc978 100644
--- a/railties/test/generators/argv_scrubber_test.rb
+++ b/railties/test/generators/argv_scrubber_test.rb
@@ -1,7 +1,9 @@
-require 'active_support/test_case'
-require 'active_support/testing/autorun'
-require 'rails/generators/rails/app/app_generator'
-require 'tempfile'
+# frozen_string_literal: true
+
+require "active_support/test_case"
+require "active_support/testing/autorun"
+require "rails/generators/rails/app/app_generator"
+require "tempfile"
 
 module Rails
   module Generators
@@ -11,7 +13,7 @@ module Rails
       # *must* act this way, I just want to prevent regressions.
 
       def test_version
-        ['-v', '--version'].each do |str|
+        ["-v", "--version"].each do |str|
           scrubber = ARGVScrubber.new [str]
           output    = nil
           exit_code = nil
@@ -26,37 +28,37 @@ module Rails
       end
 
       def test_default_help
-        argv = ['zomg', 'how', 'are', 'you']
+        argv = ["zomg", "how", "are", "you"]
         scrubber = ARGVScrubber.new argv
         args = scrubber.prepare!
-        assert_equal ['--help'] + argv.drop(1), args
+        assert_equal ["--help"] + argv.drop(1), args
       end
 
       def test_prepare_returns_args
-        scrubber = ARGVScrubber.new ['hi mom']
+        scrubber = ARGVScrubber.new ["hi mom"]
         args = scrubber.prepare!
-        assert_equal '--help', args.first
+        assert_equal "--help", args.first
       end
 
       def test_no_mutations
-        scrubber = ARGVScrubber.new ['hi mom'].freeze
+        scrubber = ARGVScrubber.new ["hi mom"].freeze
         args = scrubber.prepare!
-        assert_equal '--help', args.first
+        assert_equal "--help", args.first
       end
 
       def test_new_command_no_rc
         scrubber = Class.new(ARGVScrubber) {
           def self.default_rc_file
-            File.join(Dir.tmpdir, 'whatever')
+            File.join(Dir.tmpdir, "whatever")
           end
-        }.new ['new']
+        }.new ["new"]
         args = scrubber.prepare!
         assert_equal [], args
       end
 
       def test_new_homedir_rc
-        file = Tempfile.new 'myrcfile'
-        file.puts '--hello-world'
+        file = Tempfile.new "myrcfile"
+        file.puts "--hello-world"
         file.flush
 
         message = nil
@@ -65,10 +67,10 @@ module Rails
             file.path
           end
           define_method(:puts) { |msg| message = msg }
-        }.new ['new']
+        }.new ["new"]
         args = scrubber.prepare!
-        assert_equal ['--hello-world'], args
-        assert_match 'hello-world', message
+        assert_equal ["--hello-world"], args
+        assert_match "hello-world", message
         assert_match file.path, message
       ensure
         file.close
@@ -76,33 +78,32 @@ module Rails
       end
 
       def test_rc_whitespace_separated
-        file = Tempfile.new 'myrcfile'
-        file.puts '--hello --world'
+        file = Tempfile.new "myrcfile"
+        file.puts "--hello --world"
         file.flush
 
-        message = nil
         scrubber = Class.new(ARGVScrubber) {
-          define_method(:puts) { |msg| message = msg }
-        }.new ['new', "--rc=#{file.path}"]
+          define_method(:puts) { |msg| }
+        }.new ["new", "--rc=#{file.path}"]
         args = scrubber.prepare!
-        assert_equal ['--hello', '--world'], args
+        assert_equal ["--hello", "--world"], args
       ensure
         file.close
         file.unlink
       end
 
       def test_new_rc_option
-        file = Tempfile.new 'myrcfile'
-        file.puts '--hello-world'
+        file = Tempfile.new "myrcfile"
+        file.puts "--hello-world"
         file.flush
 
         message = nil
         scrubber = Class.new(ARGVScrubber) {
           define_method(:puts) { |msg| message = msg }
-        }.new ['new', "--rc=#{file.path}"]
+        }.new ["new", "--rc=#{file.path}"]
         args = scrubber.prepare!
-        assert_equal ['--hello-world'], args
-        assert_match 'hello-world', message
+        assert_equal ["--hello-world"], args
+        assert_match "hello-world", message
         assert_match file.path, message
       ensure
         file.close
@@ -110,14 +111,14 @@ module Rails
       end
 
       def test_new_rc_option_and_custom_options
-        file = Tempfile.new 'myrcfile'
-        file.puts '--hello'
-        file.puts '--world'
+        file = Tempfile.new "myrcfile"
+        file.puts "--hello"
+        file.puts "--world"
         file.flush
 
         scrubber = Class.new(ARGVScrubber) {
           define_method(:puts) { |msg| }
-        }.new ['new', 'tenderapp', '--love', "--rc=#{file.path}"]
+        }.new ["new", "tenderapp", "--love", "--rc=#{file.path}"]
 
         args = scrubber.prepare!
         assert_equal ["tenderapp", "--hello", "--world", "--love"], args
@@ -127,7 +128,7 @@ module Rails
       end
 
       def test_no_rc
-        scrubber = ARGVScrubber.new ['new', '--no-rc']
+        scrubber = ARGVScrubber.new ["new", "--no-rc"]
         args = scrubber.prepare!
         assert_equal [], args
       end
diff --git a/railties/test/generators/assets_generator_test.rb b/railties/test/generators/assets_generator_test.rb
index a2b94f2e50..3cec41dbf8 100644
--- a/railties/test/generators/assets_generator_test.rb
+++ b/railties/test/generators/assets_generator_test.rb
@@ -1,5 +1,7 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/rails/assets/assets_generator'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/assets/assets_generator"
 
 class AssetsGeneratorTest < Rails::Generators::TestCase
   include GeneratorsTestHelper
diff --git a/railties/test/generators/channel_generator_test.rb b/railties/test/generators/channel_generator_test.rb
index d58b54ac24..e238197eba 100644
--- a/railties/test/generators/channel_generator_test.rb
+++ b/railties/test/generators/channel_generator_test.rb
@@ -1,12 +1,14 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/channel/channel_generator'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/channel/channel_generator"
 
 class ChannelGeneratorTest < Rails::Generators::TestCase
   include GeneratorsTestHelper
   tests Rails::Generators::ChannelGenerator
 
   def test_application_cable_skeleton_is_created
-    run_generator ['books']
+    run_generator ["books"]
 
     assert_file "app/channels/application_cable/channel.rb" do |cable|
       assert_match(/module ApplicationCable\n  class Channel < ActionCable::Channel::Base\n/, cable)
@@ -18,41 +20,57 @@ class ChannelGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_channel_is_created
-    run_generator ['chat']
+    run_generator ["chat"]
+
+    assert_file "app/channels/chat_channel.rb" do |channel|
+      assert_match(/class ChatChannel < ApplicationCable::Channel/, channel)
+    end
+
+    assert_file "app/assets/javascripts/channels/chat.js" do |channel|
+      assert_match(/App\.chat = App\.cable\.subscriptions\.create\("ChatChannel/, channel)
+    end
+  end
+
+  def test_channel_with_multiple_actions_is_created
+    run_generator ["chat", "speak", "mute"]
 
     assert_file "app/channels/chat_channel.rb" do |channel|
       assert_match(/class ChatChannel < ApplicationCable::Channel/, channel)
+      assert_match(/def speak/, channel)
+      assert_match(/def mute/, channel)
     end
 
-    assert_file "app/assets/javascripts/channels/chat.coffee" do |channel|
-      assert_match(/App.cable.subscriptions.create "ChatChannel"/, channel)
+    assert_file "app/assets/javascripts/channels/chat.js" do |channel|
+      assert_match(/App\.chat = App\.cable\.subscriptions\.create\("ChatChannel/, channel)
+      assert_match(/,\n\n  speak/, channel)
+      assert_match(/,\n\n  mute: function\(\) \{\n    return this\.perform\('mute'\);\n  \}\n\}\);/, channel)
     end
   end
 
   def test_channel_asset_is_not_created_when_skip_assets_is_passed
-    run_generator ['chat', '--skip-assets']
+    run_generator ["chat", "--skip-assets"]
 
     assert_file "app/channels/chat_channel.rb" do |channel|
       assert_match(/class ChatChannel < ApplicationCable::Channel/, channel)
     end
 
-    assert_no_file "app/assets/javascripts/channels/chat.coffee"
+    assert_no_file "app/assets/javascripts/channels/chat.js"
   end
 
   def test_cable_js_is_created_if_not_present_already
-    run_generator ['chat']
+    run_generator ["chat"]
     FileUtils.rm("#{destination_root}/app/assets/javascripts/cable.js")
-    run_generator ['camp']
+    run_generator ["camp"]
 
     assert_file "app/assets/javascripts/cable.js"
   end
 
   def test_channel_on_revoke
-    run_generator ['chat']
-    run_generator ['chat'], behavior: :revoke
+    run_generator ["chat"]
+    run_generator ["chat"], behavior: :revoke
 
     assert_no_file "app/channels/chat_channel.rb"
-    assert_no_file "app/assets/javascripts/channels/chat.coffee"
+    assert_no_file "app/assets/javascripts/channels/chat.js"
 
     assert_file "app/channels/application_cable/channel.rb"
     assert_file "app/channels/application_cable/connection.rb"
diff --git a/railties/test/generators/controller_generator_test.rb b/railties/test/generators/controller_generator_test.rb
index 1351151afb..a3218951a6 100644
--- a/railties/test/generators/controller_generator_test.rb
+++ b/railties/test/generators/controller_generator_test.rb
@@ -1,5 +1,7 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/rails/controller/controller_generator'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/controller/controller_generator"
 
 class ControllerGeneratorTest < Rails::Generators::TestCase
   include GeneratorsTestHelper
@@ -19,7 +21,7 @@ class ControllerGeneratorTest < Rails::Generators::TestCase
 
   def test_check_class_collision
     Object.send :const_set, :ObjectController, Class.new
-    content = capture(:stderr){ run_generator ["object"] }
+    content = capture(:stderr) { run_generator ["object"] }
     assert_match(/The name 'ObjectController' is either already used in your application or reserved/, content)
   ensure
     Object.send :remove_const, :ObjectController
@@ -65,7 +67,7 @@ class ControllerGeneratorTest < Rails::Generators::TestCase
 
   def test_add_routes
     run_generator
-    assert_file "config/routes.rb", /get 'account\/foo'/, /get 'account\/bar'/
+    assert_file "config/routes.rb", /^  get 'account\/foo'/, /^  get 'account\/bar'/
   end
 
   def test_skip_routes
@@ -100,4 +102,11 @@ class ControllerGeneratorTest < Rails::Generators::TestCase
       assert_match(/^  namespace :admin do\n    get 'dashboard\/index'\n  end$/, route)
     end
   end
+
+  def test_namespaced_routes_with_multiple_actions_are_created_in_routes
+    run_generator ["admin/dashboard", "index", "show"]
+    assert_file "config/routes.rb" do |route|
+      assert_match(/^  namespace :admin do\n    get 'dashboard\/index'\n    get 'dashboard\/show'\n  end$/, route)
+    end
+  end
 end
diff --git a/railties/test/generators/create_migration_test.rb b/railties/test/generators/create_migration_test.rb
index e16a77479a..3cb7fd6baa 100644
--- a/railties/test/generators/create_migration_test.rb
+++ b/railties/test/generators/create_migration_test.rb
@@ -1,5 +1,7 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/rails/migration/migration_generator'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/migration/migration_generator"
 
 class CreateMigrationTest < Rails::Generators::TestCase
   include GeneratorsTestHelper
@@ -19,12 +21,12 @@ class CreateMigrationTest < Rails::Generators::TestCase
   end
 
   def create_migration(destination_path = default_destination_path, config = {}, generator_options = {}, &block)
-    migration_name = File.basename(destination_path, '.rb')
+    migration_name = File.basename(destination_path, ".rb")
     generator([migration_name], generator_options)
     generator.set_migration_assigns!(destination_path)
 
     dir, base = File.split(destination_path)
-    timestamped_destination_path = File.join(dir, ["%migration_number%", base].join('_'))
+    timestamped_destination_path = File.join(dir, ["%migration_number%", base].join("_"))
 
     @migration = Rails::Generators::Actions::CreateMigration.new(generator, timestamped_destination_path, block || "contents", config)
   end
@@ -46,7 +48,7 @@ class CreateMigrationTest < Rails::Generators::TestCase
   def test_invoke
     create_migration
 
-    assert_match(/create  db\/migrate\/1_create_articles.rb\n/, invoke!)
+    assert_match(/create  db\/migrate\/1_create_articles\.rb\n/, invoke!)
     assert_file @migration.destination
   end
 
@@ -67,7 +69,7 @@ class CreateMigrationTest < Rails::Generators::TestCase
     migration_exists!
     create_migration
 
-    assert_match(/identical  db\/migrate\/1_create_articles.rb\n/, invoke!)
+    assert_match(/identical  db\/migrate\/1_create_articles\.rb\n/, invoke!)
     assert @migration.identical?
   end
 
@@ -84,8 +86,8 @@ class CreateMigrationTest < Rails::Generators::TestCase
     create_migration(dest, force: true) { "different content" }
 
     stdout = invoke!
-    assert_match(/remove  db\/migrate\/1_migration.rb\n/, stdout)
-    assert_match(/create  db\/migrate\/2_migration.rb\n/, stdout)
+    assert_match(/remove  db\/migrate\/1_migration\.rb\n/, stdout)
+    assert_match(/create  db\/migrate\/2_migration\.rb\n/, stdout)
     assert_file @migration.destination
     assert_no_file @existing_migration.destination
   end
@@ -97,8 +99,8 @@ class CreateMigrationTest < Rails::Generators::TestCase
     end
 
     stdout = invoke!
-    assert_match(/remove  db\/migrate\/1_create_articles.rb\n/, stdout)
-    assert_match(/create  db\/migrate\/2_create_articles.rb\n/, stdout)
+    assert_match(/remove  db\/migrate\/1_create_articles\.rb\n/, stdout)
+    assert_match(/create  db\/migrate\/2_create_articles\.rb\n/, stdout)
     assert_no_file @migration.destination
   end
 
@@ -106,7 +108,7 @@ class CreateMigrationTest < Rails::Generators::TestCase
     migration_exists!
     create_migration(default_destination_path, {}, { skip: true }) { "different content" }
 
-    assert_match(/skip  db\/migrate\/2_create_articles.rb\n/, invoke!)
+    assert_match(/skip  db\/migrate\/2_create_articles\.rb\n/, invoke!)
     assert_no_file @migration.destination
   end
 
@@ -114,7 +116,7 @@ class CreateMigrationTest < Rails::Generators::TestCase
     migration_exists!
     create_migration
 
-    assert_match(/remove  db\/migrate\/1_create_articles.rb\n/, revoke!)
+    assert_match(/remove  db\/migrate\/1_create_articles\.rb\n/, revoke!)
     assert_no_file @existing_migration.destination
   end
 
@@ -122,13 +124,13 @@ class CreateMigrationTest < Rails::Generators::TestCase
     migration_exists!
     create_migration(default_destination_path, {}, { pretend: true })
 
-    assert_match(/remove  db\/migrate\/1_create_articles.rb\n/, revoke!)
+    assert_match(/remove  db\/migrate\/1_create_articles\.rb\n/, revoke!)
     assert_file @existing_migration.destination
   end
 
   def test_revoke_when_no_exists
     create_migration
 
-    assert_match(/remove  db\/migrate\/1_create_articles.rb\n/, revoke!)
+    assert_match(/remove  db\/migrate\/1_create_articles\.rb\n/, revoke!)
   end
 end
diff --git a/railties/test/generators/encrypted_secrets_generator_test.rb b/railties/test/generators/encrypted_secrets_generator_test.rb
new file mode 100644
index 0000000000..eacb5166c0
--- /dev/null
+++ b/railties/test/generators/encrypted_secrets_generator_test.rb
@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/encrypted_secrets/encrypted_secrets_generator"
+
+class EncryptedSecretsGeneratorTest < Rails::Generators::TestCase
+  include GeneratorsTestHelper
+
+  def setup
+    super
+    cd destination_root
+  end
+
+  def test_generates_key_file_and_encrypted_secrets_file
+    run_generator
+
+    assert_file "config/secrets.yml.key", /\w+/
+
+    assert File.exist?("config/secrets.yml.enc")
+    assert_no_match(/# production:\n#   external_api_key: \w+/, IO.binread("config/secrets.yml.enc"))
+    assert_match(/# production:\n#   external_api_key: \w+/, Rails::Secrets.read)
+  end
+
+  def test_appends_to_gitignore
+    FileUtils.touch(".gitignore")
+
+    run_generator
+
+    assert_file ".gitignore", /config\/secrets.yml.key/, /(?!config\/secrets.yml.enc)/
+  end
+
+  def test_warns_when_ignore_is_missing
+    assert_match(/Add this to your ignore file/i, run_generator)
+  end
+
+  def test_doesnt_generate_a_new_key_file_if_already_opted_in_to_encrypted_secrets
+    FileUtils.mkdir("config")
+    File.open("config/secrets.yml.enc", "w") { |f| f.puts "already secrety" }
+
+    run_generator
+
+    assert_no_file "config/secrets.yml.key"
+  end
+end
diff --git a/railties/test/generators/generated_attribute_test.rb b/railties/test/generators/generated_attribute_test.rb
index ee7c009305..c6f7bdeda1 100644
--- a/railties/test/generators/generated_attribute_test.rb
+++ b/railties/test/generators/generated_attribute_test.rb
@@ -1,5 +1,7 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/generated_attribute'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/generated_attribute"
 
 class GeneratedAttributeTest < Rails::Generators::TestCase
   include GeneratorsTestHelper
@@ -51,7 +53,7 @@ class GeneratedAttributeTest < Rails::Generators::TestCase
   end
 
   def test_default_value_is_decimal
-    assert_field_default_value :decimal, '9.99'
+    assert_field_default_value :decimal, "9.99"
   end
 
   def test_default_value_is_datetime
@@ -65,7 +67,7 @@ class GeneratedAttributeTest < Rails::Generators::TestCase
   end
 
   def test_default_value_is_string
-    assert_field_default_value :string, 'MyString'
+    assert_field_default_value :string, "MyString"
   end
 
   def test_default_value_for_type
@@ -74,7 +76,7 @@ class GeneratedAttributeTest < Rails::Generators::TestCase
   end
 
   def test_default_value_is_text
-    assert_field_default_value :text, 'MyText'
+    assert_field_default_value :text, "MyText"
   end
 
   def test_default_value_is_boolean
@@ -89,14 +91,14 @@ class GeneratedAttributeTest < Rails::Generators::TestCase
 
   def test_default_value_is_empty_string
     %w(foo bar baz).each do |attribute_type|
-      assert_field_default_value attribute_type, ''
+      assert_field_default_value attribute_type, ""
     end
   end
 
   def test_human_name
     assert_equal(
-      'Full name',
-      create_generated_attribute(:string, 'full_name').human_name
+      "Full name",
+      create_generated_attribute(:string, "full_name").human_name
     )
   end
 
@@ -125,21 +127,21 @@ class GeneratedAttributeTest < Rails::Generators::TestCase
   end
 
   def test_blank_type_defaults_to_string_raises_exception
-    assert_equal :string, create_generated_attribute(nil, 'title').type
-    assert_equal :string, create_generated_attribute("", 'title').type
+    assert_equal :string, create_generated_attribute(nil, "title").type
+    assert_equal :string, create_generated_attribute("", "title").type
   end
 
   def test_handles_index_names_for_references
-    assert_equal "post", create_generated_attribute('string', 'post').index_name
-    assert_equal "post_id", create_generated_attribute('references', 'post').index_name
-    assert_equal "post_id", create_generated_attribute('belongs_to', 'post').index_name
-    assert_equal ["post_id", "post_type"], create_generated_attribute('references{polymorphic}', 'post').index_name
+    assert_equal "post", create_generated_attribute("string", "post").index_name
+    assert_equal "post_id", create_generated_attribute("references", "post").index_name
+    assert_equal "post_id", create_generated_attribute("belongs_to", "post").index_name
+    assert_equal ["post_id", "post_type"], create_generated_attribute("references{polymorphic}", "post").index_name
   end
 
   def test_handles_column_names_for_references
-    assert_equal "post", create_generated_attribute('string', 'post').column_name
-    assert_equal "post_id", create_generated_attribute('references', 'post').column_name
-    assert_equal "post_id", create_generated_attribute('belongs_to', 'post').column_name
+    assert_equal "post", create_generated_attribute("string", "post").column_name
+    assert_equal "post_id", create_generated_attribute("references", "post").column_name
+    assert_equal "post_id", create_generated_attribute("belongs_to", "post").column_name
   end
 
   def test_parse_required_attribute_with_index
diff --git a/railties/test/generators/generator_generator_test.rb b/railties/test/generators/generator_generator_test.rb
index dcfeaaa8e0..eaa964cabc 100644
--- a/railties/test/generators/generator_generator_test.rb
+++ b/railties/test/generators/generator_generator_test.rb
@@ -1,5 +1,7 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/rails/generator/generator_generator'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/generator/generator_generator"
 
 class GeneratorGeneratorTest < Rails::Generators::TestCase
   include GeneratorsTestHelper
@@ -12,7 +14,7 @@ class GeneratorGeneratorTest < Rails::Generators::TestCase
       lib/generators/awesome
       lib/generators/awesome/USAGE
       lib/generators/awesome/templates
-    ).each{ |path| assert_file path }
+    ).each { |path| assert_file path }
 
     assert_file "lib/generators/awesome/awesome_generator.rb",
                 /class AwesomeGenerator < Rails::Generators::NamedBase/
@@ -28,7 +30,7 @@ class GeneratorGeneratorTest < Rails::Generators::TestCase
       lib/generators/rails/awesome
       lib/generators/rails/awesome/USAGE
       lib/generators/rails/awesome/templates
-    ).each{ |path| assert_file path }
+    ).each { |path| assert_file path }
 
     assert_file "lib/generators/rails/awesome/awesome_generator.rb",
                 /class Rails::AwesomeGenerator < Rails::Generators::NamedBase/
@@ -44,7 +46,7 @@ class GeneratorGeneratorTest < Rails::Generators::TestCase
       lib/generators/
       lib/generators/USAGE
       lib/generators/templates
-    ).each{ |path| assert_file path }
+    ).each { |path| assert_file path }
 
     assert_file "lib/generators/awesome_generator.rb",
                 /class AwesomeGenerator < Rails::Generators::NamedBase/
@@ -60,7 +62,7 @@ class GeneratorGeneratorTest < Rails::Generators::TestCase
       lib/generators/rails
       lib/generators/rails/USAGE
       lib/generators/rails/templates
-    ).each{ |path| assert_file path }
+    ).each { |path| assert_file path }
 
     assert_file "lib/generators/rails/awesome_generator.rb",
                 /class Rails::AwesomeGenerator < Rails::Generators::NamedBase/
diff --git a/railties/test/generators/generator_test.rb b/railties/test/generators/generator_test.rb
index 8ef44a8dcb..5f7daf5ac3 100644
--- a/railties/test/generators/generator_test.rb
+++ b/railties/test/generators/generator_test.rb
@@ -1,6 +1,8 @@
-require 'active_support/test_case'
-require 'active_support/testing/autorun'
-require 'rails/generators/app_base'
+# frozen_string_literal: true
+
+require "active_support/test_case"
+require "active_support/testing/autorun"
+require "rails/generators/app_base"
 
 module Rails
   module Generators
@@ -20,47 +22,47 @@ module Rails
       end
 
       def test_construction
-        klass     = make_builder_class
-        assert klass.start(['new', 'blah'])
+        klass = make_builder_class
+        assert klass.start(["new", "blah"])
       end
 
       def test_add_gem
         klass = make_builder_class
-        generator = klass.start(['new', 'blah'])
-        generator.gemfile_entry 'tenderlove'
-        assert_includes generator.gemfile_entries.map(&:name), 'tenderlove'
+        generator = klass.start(["new", "blah"])
+        generator.gemfile_entry "tenderlove"
+        assert_includes generator.gemfile_entries.map(&:name), "tenderlove"
       end
 
       def test_add_gem_with_version
         klass = make_builder_class
-        generator = klass.start(['new', 'blah'])
-        generator.gemfile_entry 'tenderlove', '2.0.0'
+        generator = klass.start(["new", "blah"])
+        generator.gemfile_entry "tenderlove", "2.0.0"
         assert generator.gemfile_entries.find { |gfe|
-          gfe.name == 'tenderlove' && gfe.version == '2.0.0'
+          gfe.name == "tenderlove" && gfe.version == "2.0.0"
         }
       end
 
       def test_add_github_gem
         klass = make_builder_class
-        generator = klass.start(['new', 'blah'])
-        generator.gemfile_entry 'tenderlove', github: 'hello world'
+        generator = klass.start(["new", "blah"])
+        generator.gemfile_entry "tenderlove", github: "hello world"
         assert generator.gemfile_entries.find { |gfe|
-          gfe.name == 'tenderlove' && gfe.options[:github] == 'hello world'
+          gfe.name == "tenderlove" && gfe.options[:github] == "hello world"
         }
       end
 
       def test_add_path_gem
         klass = make_builder_class
-        generator = klass.start(['new', 'blah'])
-        generator.gemfile_entry 'tenderlove', path: 'hello world'
+        generator = klass.start(["new", "blah"])
+        generator.gemfile_entry "tenderlove", path: "hello world"
         assert generator.gemfile_entries.find { |gfe|
-          gfe.name == 'tenderlove' && gfe.options[:path] == 'hello world'
+          gfe.name == "tenderlove" && gfe.options[:path] == "hello world"
         }
       end
 
       def test_filter
         klass     = make_builder_class
-        generator = klass.start(['new', 'blah'])
+        generator = klass.start(["new", "blah"])
         gems      = generator.gemfile_entries
         generator.add_gem_entry_filter { |gem|
           gem.name != gems.first.name
@@ -70,7 +72,7 @@ module Rails
 
       def test_two_filters
         klass     = make_builder_class
-        generator = klass.start(['new', 'blah'])
+        generator = klass.start(["new", "blah"])
         gems      = generator.gemfile_entries
         generator.add_gem_entry_filter { |gem|
           gem.name != gems.first.name
@@ -83,17 +85,17 @@ module Rails
 
       def test_recommended_rails_versions
         klass     = make_builder_class
-        generator = klass.start(['new', 'blah'])
+        generator = klass.start(["new", "blah"])
 
         specifier_for = -> v { generator.send(:rails_version_specifier, Gem::Version.new(v)) }
 
-        assert_equal '~> 4.1.13', specifier_for['4.1.13']
-        assert_equal ['>= 4.1.6.rc1', '< 4.2'], specifier_for['4.1.6.rc1']
-        assert_equal ['~> 4.1.7', '>= 4.1.7.1'], specifier_for['4.1.7.1']
-        assert_equal ['~> 4.1.7', '>= 4.1.7.1.2'], specifier_for['4.1.7.1.2']
-        assert_equal ['>= 4.1.7.1.rc2', '< 4.2'], specifier_for['4.1.7.1.rc2']
-        assert_equal ['>= 4.2.0.beta1', '< 4.3'], specifier_for['4.2.0.beta1']
-        assert_equal ['>= 5.0.0.beta1', '< 5.1'], specifier_for['5.0.0.beta1']
+        assert_equal "~> 4.1.13", specifier_for["4.1.13"]
+        assert_equal "~> 4.1.6.rc1", specifier_for["4.1.6.rc1"]
+        assert_equal ["~> 4.1.7", ">= 4.1.7.1"], specifier_for["4.1.7.1"]
+        assert_equal ["~> 4.1.7", ">= 4.1.7.1.2"], specifier_for["4.1.7.1.2"]
+        assert_equal ["~> 4.1.7", ">= 4.1.7.1.rc2"], specifier_for["4.1.7.1.rc2"]
+        assert_equal "~> 4.2.0.beta1", specifier_for["4.2.0.beta1"]
+        assert_equal "~> 5.0.0.beta1", specifier_for["5.0.0.beta1"]
       end
     end
   end
diff --git a/railties/test/generators/generators_test_helper.rb b/railties/test/generators/generators_test_helper.rb
index b19a5a7144..cb5d8da7b1 100644
--- a/railties/test/generators/generators_test_helper.rb
+++ b/railties/test/generators/generators_test_helper.rb
@@ -1,15 +1,17 @@
-require 'abstract_unit'
-require 'active_support/core_ext/module/remove_method'
-require 'active_support/testing/stream'
-require 'active_support/testing/method_call_assertions'
-require 'rails/generators'
-require 'rails/generators/test_case'
+# frozen_string_literal: true
+
+require "abstract_unit"
+require "active_support/core_ext/module/remove_method"
+require "active_support/testing/stream"
+require "active_support/testing/method_call_assertions"
+require "rails/generators"
+require "rails/generators/test_case"
 
 module Rails
   class << self
     remove_possible_method :root
     def root
-      @root ||= Pathname.new(File.expand_path('../../fixtures', __FILE__))
+      @root ||= Pathname.new(File.expand_path("../fixtures", __dir__))
     end
   end
 end
@@ -20,9 +22,9 @@ Rails.application.config.generators.templates = [File.join(Rails.root, "lib", "t
 # Rails.application.config.generators to Rails::Generators
 Rails.application.load_generators
 
-require 'active_record'
-require 'action_dispatch'
-require 'action_view'
+require "active_record"
+require "action_dispatch"
+require "action_view"
 
 module GeneratorsTestHelper
   include ActiveSupport::Testing::Stream
@@ -34,17 +36,16 @@ module GeneratorsTestHelper
       setup :prepare_destination
 
       begin
-        base.tests Rails::Generators.const_get(base.name.sub(/Test$/, ''))
+        base.tests Rails::Generators.const_get(base.name.sub(/Test$/, ""))
       rescue
       end
     end
   end
 
   def copy_routes
-    routes = File.expand_path("../../../lib/rails/generators/rails/app/templates/config/routes.rb", __FILE__)
+    routes = File.expand_path("../../lib/rails/generators/rails/app/templates/config/routes.rb", __dir__)
     destination = File.join(destination_root, "config")
     FileUtils.mkdir_p(destination)
     FileUtils.cp routes, destination
   end
-
 end
diff --git a/railties/test/generators/helper_generator_test.rb b/railties/test/generators/helper_generator_test.rb
index add04f21a4..4cdb6adf82 100644
--- a/railties/test/generators/helper_generator_test.rb
+++ b/railties/test/generators/helper_generator_test.rb
@@ -1,5 +1,7 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/rails/helper/helper_generator'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/helper/helper_generator"
 
 ObjectHelper = Class.new
 AnotherObjectHelperTest = Class.new
@@ -14,7 +16,7 @@ class HelperGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_check_class_collision
-    content = capture(:stderr){ run_generator ["object"] }
+    content = capture(:stderr) { run_generator ["object"] }
     assert_match(/The name 'ObjectHelper' is either already used in your application or reserved/, content)
   end
 
diff --git a/railties/test/generators/integration_test_generator_test.rb b/railties/test/generators/integration_test_generator_test.rb
index d05ed76d24..82791f1a27 100644
--- a/railties/test/generators/integration_test_generator_test.rb
+++ b/railties/test/generators/integration_test_generator_test.rb
@@ -1,12 +1,18 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/rails/integration_test/integration_test_generator'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/integration_test/integration_test_generator"
 
 class IntegrationTestGeneratorTest < Rails::Generators::TestCase
   include GeneratorsTestHelper
-  arguments %w(integration)
 
   def test_integration_test_skeleton_is_created
-    run_generator
+    run_generator %w(integration)
     assert_file "test/integration/integration_test.rb", /class IntegrationTest < ActionDispatch::IntegrationTest/
   end
+
+  def test_namespaced_integration_test_skeleton_is_created
+    run_generator %w(iguchi/integration)
+    assert_file "test/integration/iguchi/integration_test.rb", /class Iguchi::IntegrationTest < ActionDispatch::IntegrationTest/
+  end
 end
diff --git a/railties/test/generators/job_generator_test.rb b/railties/test/generators/job_generator_test.rb
index dbff0ab704..13276fac65 100644
--- a/railties/test/generators/job_generator_test.rb
+++ b/railties/test/generators/job_generator_test.rb
@@ -1,5 +1,7 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/job/job_generator'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/job/job_generator"
 
 class JobGeneratorTest < Rails::Generators::TestCase
   include GeneratorsTestHelper
diff --git a/railties/test/generators/mailer_generator_test.rb b/railties/test/generators/mailer_generator_test.rb
index 8728b39dae..ddac6e1a1e 100644
--- a/railties/test/generators/mailer_generator_test.rb
+++ b/railties/test/generators/mailer_generator_test.rb
@@ -1,5 +1,7 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/mailer/mailer_generator'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/mailer/mailer_generator"
 
 class MailerGeneratorTest < Rails::Generators::TestCase
   include GeneratorsTestHelper
@@ -9,13 +11,13 @@ class MailerGeneratorTest < Rails::Generators::TestCase
     run_generator
     assert_file "app/mailers/notifier_mailer.rb" do |mailer|
       assert_match(/class NotifierMailer < ApplicationMailer/, mailer)
-      assert_no_match(/default from: "from@example.com"/, mailer)
+      assert_no_match(/default from: "from@example\.com"/, mailer)
       assert_no_match(/layout :mailer_notifier/, mailer)
     end
 
-    assert_file 'app/mailers/application_mailer.rb' do |mailer|
+    assert_file "app/mailers/application_mailer.rb" do |mailer|
       assert_match(/class ApplicationMailer < ActionMailer::Base/, mailer)
-      assert_match(/default from: 'from@example.com'/, mailer)
+      assert_match(/default from: 'from@example\.com'/, mailer)
       assert_match(/layout 'mailer'/, mailer)
     end
   end
@@ -30,7 +32,7 @@ class MailerGeneratorTest < Rails::Generators::TestCase
 
   def test_check_class_collision
     Object.send :const_set, :NotifierMailer, Class.new
-    content = capture(:stderr){ run_generator }
+    content = capture(:stderr) { run_generator }
     assert_match(/The name 'NotifierMailer' is either already used in your application or reserved/, content)
   ensure
     Object.send :remove_const, :NotifierMailer
@@ -48,18 +50,18 @@ class MailerGeneratorTest < Rails::Generators::TestCase
       assert_match(/class NotifierMailerPreview < ActionMailer::Preview/, preview)
       assert_match(/\# Preview this email at http:\/\/localhost\:3000\/rails\/mailers\/notifier_mailer\/foo/, preview)
       assert_instance_method :foo, preview do |foo|
-        assert_match(/NotifierMailer.foo/, foo)
+        assert_match(/NotifierMailer\.foo/, foo)
       end
       assert_match(/\# Preview this email at http:\/\/localhost\:3000\/rails\/mailers\/notifier_mailer\/bar/, preview)
       assert_instance_method :bar, preview do |bar|
-        assert_match(/NotifierMailer.bar/, bar)
+        assert_match(/NotifierMailer\.bar/, bar)
       end
     end
   end
 
   def test_check_test_class_collision
     Object.send :const_set, :NotifierMailerTest, Class.new
-    content = capture(:stderr){ run_generator }
+    content = capture(:stderr) { run_generator }
     assert_match(/The name 'NotifierMailerTest' is either already used in your application or reserved/, content)
   ensure
     Object.send :remove_const, :NotifierMailerTest
@@ -67,7 +69,7 @@ class MailerGeneratorTest < Rails::Generators::TestCase
 
   def test_check_preview_class_collision
     Object.send :const_set, :NotifierMailerPreview, Class.new
-    content = capture(:stderr){ run_generator }
+    content = capture(:stderr) { run_generator }
     assert_match(/The name 'NotifierMailerPreview' is either already used in your application or reserved/, content)
   ensure
     Object.send :remove_const, :NotifierMailerPreview
@@ -84,6 +86,10 @@ class MailerGeneratorTest < Rails::Generators::TestCase
       assert_match(%r(\sapp/views/notifier_mailer/bar\.text\.erb), view)
       assert_match(/<%= @greeting %>/, view)
     end
+
+    assert_file "app/views/layouts/mailer.text.erb" do |view|
+      assert_match(/<%= yield %>/, view)
+    end
   end
 
   def test_invokes_default_html_template_engine
@@ -97,6 +103,10 @@ class MailerGeneratorTest < Rails::Generators::TestCase
       assert_match(%r(\sapp/views/notifier_mailer/bar\.html\.erb), view)
       assert_match(/<%= @greeting %>/, view)
     end
+
+    assert_file "app/views/layouts/mailer.html.erb" do |view|
+      assert_match(%r{<body>\n    <%= yield %>\n  </body>}, view)
+    end
   end
 
   def test_invokes_default_template_engine_even_with_no_action
@@ -129,12 +139,12 @@ class MailerGeneratorTest < Rails::Generators::TestCase
 
     assert_file "app/mailers/notifier_mailer.rb" do |mailer|
       assert_instance_method :foo, mailer do |foo|
-        assert_match(/mail to: "to@example.org"/, foo)
+        assert_match(/mail to: "to@example\.org"/, foo)
         assert_match(/@greeting = "Hi"/, foo)
       end
 
       assert_instance_method :bar, mailer do |bar|
-        assert_match(/mail to: "to@example.org"/, bar)
+        assert_match(/mail to: "to@example\.org"/, bar)
         assert_match(/@greeting = "Hi"/, bar)
       end
     end
diff --git a/railties/test/generators/migration_generator_test.rb b/railties/test/generators/migration_generator_test.rb
index 46154b7db2..88a939a55a 100644
--- a/railties/test/generators/migration_generator_test.rb
+++ b/railties/test/generators/migration_generator_test.rb
@@ -1,5 +1,7 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/rails/migration/migration_generator'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/migration/migration_generator"
 
 class MigrationGeneratorTest < Rails::Generators::TestCase
   include GeneratorsTestHelper
@@ -17,7 +19,7 @@ class MigrationGeneratorTest < Rails::Generators::TestCase
       run_generator [migration]
       file_name = migration_file_name "db/migrate/#{migration}.rb"
 
-      File.basename(file_name).split('_').first
+      File.basename(file_name).split("_").first
     end
 
     assert_not_equal first_migration_number, second_migration_number
@@ -48,6 +50,17 @@ class MigrationGeneratorTest < Rails::Generators::TestCase
     end
   end
 
+  def test_add_migration_with_table_having_from_in_title
+    migration = "add_email_address_to_blacklisted_from_campaign"
+    run_generator [migration, "email_address:string"]
+
+    assert_migration "db/migrate/#{migration}.rb" do |content|
+      assert_method :change, content do |change|
+        assert_match(/add_column :blacklisted_from_campaigns, :email_address, :string/, change)
+      end
+    end
+  end
+
   def test_remove_migration_with_indexed_attribute
     migration = "remove_title_body_from_posts"
     run_generator [migration, "title:string:index", "body:text"]
@@ -73,6 +86,17 @@ class MigrationGeneratorTest < Rails::Generators::TestCase
     end
   end
 
+  def test_remove_migration_with_table_having_to_in_title
+    migration = "remove_email_address_from_sent_to_user"
+    run_generator [migration, "email_address:string"]
+
+    assert_migration "db/migrate/#{migration}.rb" do |content|
+      assert_method :change, content do |change|
+        assert_match(/remove_column :sent_to_users, :email_address, :string/, change)
+      end
+    end
+  end
+
   def test_remove_migration_with_references_options
     migration = "remove_references_from_books"
     run_generator [migration, "author:belongs_to", "distributor:references{polymorphic}"]
@@ -204,8 +228,8 @@ class MigrationGeneratorTest < Rails::Generators::TestCase
     assert_migration "db/migrate/#{migration}.rb" do |content|
       assert_method :change, content do |change|
         assert_match(/create_join_table :artists, :musics/, change)
-        assert_match(/# t.index \[:artist_id, :music_id\]/, change)
-        assert_match(/  t.index \[:music_id, :artist_id\], unique: true/, change)
+        assert_match(/# t\.index \[:artist_id, :music_id\]/, change)
+        assert_match(/  t\.index \[:music_id, :artist_id\], unique: true/, change)
       end
     end
   end
@@ -248,7 +272,7 @@ class MigrationGeneratorTest < Rails::Generators::TestCase
   def test_migration_with_singular_table_name
     with_singular_table_name do
       migration = "add_title_body_to_post"
-      run_generator [migration, 'title:string']
+      run_generator [migration, "title:string"]
       assert_migration "db/migrate/#{migration}.rb" do |content|
         assert_method :change, content do |change|
           assert_match(/add_column :post, :title, :string/, change)
@@ -265,8 +289,8 @@ class MigrationGeneratorTest < Rails::Generators::TestCase
       assert_migration "db/migrate/#{migration}.rb" do |content|
         assert_method :change, content do |change|
           assert_match(/create_join_table :artist, :music/, change)
-          assert_match(/# t.index \[:artist_id, :music_id\]/, change)
-          assert_match(/  t.index \[:music_id, :artist_id\], unique: true/, change)
+          assert_match(/# t\.index \[:artist_id, :music_id\]/, change)
+          assert_match(/  t\.index \[:music_id, :artist_id\], unique: true/, change)
         end
       end
     end
@@ -309,6 +333,17 @@ class MigrationGeneratorTest < Rails::Generators::TestCase
     end
   end
 
+  def test_add_migration_to_configured_path
+    old_paths = Rails.application.config.paths["db/migrate"]
+    Rails.application.config.paths.add "db/migrate", with: "db2/migrate"
+
+    migration = "migration_in_custom_path"
+    run_generator [migration]
+    assert_migration "db2/migrate/#{migration}.rb", /.*/
+  ensure
+    Rails.application.config.paths["db/migrate"] = old_paths
+  end
+
   private
 
     def with_singular_table_name
diff --git a/railties/test/generators/model_generator_test.rb b/railties/test/generators/model_generator_test.rb
index ed6846abc3..516aa0704f 100644
--- a/railties/test/generators/model_generator_test.rb
+++ b/railties/test/generators/model_generator_test.rb
@@ -1,19 +1,13 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/rails/model/model_generator'
-require 'active_support/core_ext/string/strip'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/model/model_generator"
+require "active_support/core_ext/string/strip"
 
 class ModelGeneratorTest < Rails::Generators::TestCase
   include GeneratorsTestHelper
   arguments %w(Account name:string age:integer)
 
-   def test_application_record_skeleton_is_created
-     run_generator
-     assert_file "app/models/application_record.rb" do |record|
-       assert_match(/class ApplicationRecord < ActiveRecord::Base/, record)
-       assert_match(/self.abstract_class = true/, record)
-     end
-   end
-
   def test_help_shows_invoked_generators_options
     content = run_generator ["--help"]
     assert_match(/ActiveRecord options:/, content)
@@ -34,7 +28,7 @@ class ModelGeneratorTest < Rails::Generators::TestCase
 
   def test_invokes_default_orm
     run_generator
-    assert_file "app/models/account.rb", /class Account < ActiveRecord::Base/
+    assert_file "app/models/account.rb", /class Account < ApplicationRecord/
   end
 
   def test_model_with_parent_option
@@ -43,20 +37,9 @@ class ModelGeneratorTest < Rails::Generators::TestCase
     assert_no_migration "db/migrate/create_accounts.rb"
   end
 
-  def test_model_with_existent_application_record
-    mkdir_p "#{destination_root}/app/models"
-    touch "#{destination_root}/app/models/application_record.rb"
-
-    Dir.chdir(destination_root) do
-      run_generator ["account"]
-    end
-
-    assert_file "app/models/account.rb", /class Account < ApplicationRecord/
-  end
-
   def test_plural_names_are_singularized
     content = run_generator ["accounts".freeze]
-    assert_file "app/models/account.rb", /class Account < ActiveRecord::Base/
+    assert_file "app/models/account.rb", /class Account < ApplicationRecord/
     assert_file "test/models/account_test.rb", /class AccountTest/
     assert_match(/\[WARNING\] The model name 'accounts' was recognized as a plural, using the singular 'account' instead\. Override with --force-plural or setup custom inflection rules for this noun before running the generator\./, content)
   end
@@ -71,7 +54,7 @@ class ModelGeneratorTest < Rails::Generators::TestCase
     assert_file "app/models/admin.rb", /module Admin/
     assert_file "app/models/admin.rb", /def self\.table_name_prefix/
     assert_file "app/models/admin.rb", /'admin_'/
-    assert_file "app/models/admin/account.rb", /class Admin::Account < ActiveRecord::Base/
+    assert_file "app/models/admin/account.rb", /class Admin::Account < ApplicationRecord/
   end
 
   def test_migration
@@ -212,14 +195,25 @@ class ModelGeneratorTest < Rails::Generators::TestCase
   def test_migration_without_timestamps
     ActiveRecord::Base.timestamped_migrations = false
     run_generator ["account"]
-    assert_file  "db/migrate/001_create_accounts.rb", /class CreateAccounts < ActiveRecord::Migration\[[0-9.]+\]/
+    assert_file "db/migrate/001_create_accounts.rb", /class CreateAccounts < ActiveRecord::Migration\[[0-9.]+\]/
 
     run_generator ["project"]
-    assert_file  "db/migrate/002_create_projects.rb", /class CreateProjects < ActiveRecord::Migration\[[0-9.]+\]/
+    assert_file "db/migrate/002_create_projects.rb", /class CreateProjects < ActiveRecord::Migration\[[0-9.]+\]/
   ensure
     ActiveRecord::Base.timestamped_migrations = true
   end
 
+  def test_migration_with_configured_path
+    old_paths = Rails.application.config.paths["db/migrate"]
+    Rails.application.config.paths.add "db/migrate", with: "db2/migrate"
+
+    run_generator
+
+    assert_migration "db2/migrate/create_accounts.rb", /class CreateAccounts < ActiveRecord::Migration\[[0-9.]+\]/
+  ensure
+    Rails.application.config.paths["db/migrate"] = old_paths
+  end
+
   def test_model_with_references_attribute_generates_belongs_to_associations
     run_generator ["product", "name:string", "supplier:references"]
     assert_file "app/models/product.rb", /belongs_to :supplier/
@@ -242,7 +236,7 @@ class ModelGeneratorTest < Rails::Generators::TestCase
 
   def test_migration_with_timestamps
     run_generator
-    assert_migration "db/migrate/create_accounts.rb", /t.timestamps/
+    assert_migration "db/migrate/create_accounts.rb", /t\.timestamps/
   end
 
   def test_migration_timestamps_are_skipped
@@ -250,7 +244,7 @@ class ModelGeneratorTest < Rails::Generators::TestCase
 
     assert_migration "db/migrate/create_accounts.rb" do |m|
       assert_method :change, m do |up|
-        assert_no_match(/t.timestamps/, up)
+        assert_no_match(/t\.timestamps/, up)
       end
     end
   end
@@ -258,24 +252,24 @@ class ModelGeneratorTest < Rails::Generators::TestCase
   def test_migration_is_skipped_with_skip_option
     run_generator
     output = run_generator ["Account", "--skip"]
-    assert_match %r{skip\s+db/migrate/\d+_create_accounts.rb}, output
+    assert_match %r{skip\s+db/migrate/\d+_create_accounts\.rb}, output
   end
 
   def test_migration_is_ignored_as_identical_with_skip_option
     run_generator ["Account"]
     output = run_generator ["Account", "--skip"]
-    assert_match %r{identical\s+db/migrate/\d+_create_accounts.rb}, output
+    assert_match %r{identical\s+db/migrate/\d+_create_accounts\.rb}, output
   end
 
   def test_migration_is_skipped_on_skip_behavior
     run_generator
     output = run_generator ["Account"], behavior: :skip
-    assert_match %r{skip\s+db/migrate/\d+_create_accounts.rb}, output
+    assert_match %r{skip\s+db/migrate/\d+_create_accounts\.rb}, output
   end
 
   def test_migration_error_is_not_shown_on_revoke
     run_generator
-    error = capture(:stderr){ run_generator ["Account"], behavior: :revoke }
+    error = capture(:stderr) { run_generator ["Account"], behavior: :revoke }
     assert_no_match(/Another migration is already named create_accounts/, error)
   end
 
@@ -300,7 +294,7 @@ class ModelGeneratorTest < Rails::Generators::TestCase
 
     assert_file "test/fixtures/accounts.yml", /name: MyString/, /age: 1/
     assert_generated_fixture("test/fixtures/accounts.yml",
-                             {"one"=>{"name"=>"MyString", "age"=>1}, "two"=>{"name"=>"MyString", "age"=>1}})
+                             "one" => { "name" => "MyString", "age" => 1 }, "two" => { "name" => "MyString", "age" => 1 })
   end
 
   def test_fixtures_use_the_references_ids
@@ -308,7 +302,7 @@ class ModelGeneratorTest < Rails::Generators::TestCase
 
     assert_file "test/fixtures/line_items.yml", /product: one\n  cart: one/
     assert_generated_fixture("test/fixtures/line_items.yml",
-                             {"one"=>{"product"=>"one", "cart"=>"one"}, "two"=>{"product"=>"two", "cart"=>"two"}})
+                             "one" => { "product" => "one", "cart" => "one" }, "two" => { "product" => "two", "cart" => "two" })
   end
 
   def test_fixtures_use_the_references_ids_and_type
@@ -316,15 +310,15 @@ class ModelGeneratorTest < Rails::Generators::TestCase
 
     assert_file "test/fixtures/line_items.yml", /product: one\n  product_type: Product\n  cart: one/
     assert_generated_fixture("test/fixtures/line_items.yml",
-                             {"one"=>{"product"=>"one", "product_type"=>"Product", "cart"=>"one"},
-                              "two"=>{"product"=>"two", "product_type"=>"Product", "cart"=>"two"}})
+                             "one" => { "product" => "one", "product_type" => "Product", "cart" => "one" },
+                              "two" => { "product" => "two", "product_type" => "Product", "cart" => "two" })
   end
 
   def test_fixtures_respect_reserved_yml_keywords
     run_generator ["LineItem", "no:integer", "Off:boolean", "ON:boolean"]
 
     assert_generated_fixture("test/fixtures/line_items.yml",
-                             {"one"=>{"no"=>1, "Off"=>false, "ON"=>false}, "two"=>{"no"=>1, "Off"=>false, "ON"=>false}})
+                             "one" => { "no" => 1, "Off" => false, "ON" => false }, "two" => { "no" => 1, "Off" => false, "ON" => false })
   end
 
   def test_fixture_is_skipped
@@ -343,13 +337,13 @@ class ModelGeneratorTest < Rails::Generators::TestCase
     ActiveRecord::Base.pluralize_table_names = false
     run_generator
     assert_generated_fixture("test/fixtures/account.yml",
-                             {"one"=>{"name"=>"MyString", "age"=>1}, "two"=>{"name"=>"MyString", "age"=>1}})
+                             "one" => { "name" => "MyString", "age" => 1 }, "two" => { "name" => "MyString", "age" => 1 })
   ensure
     ActiveRecord::Base.pluralize_table_names = original_pluralize_table_name
   end
 
   def test_check_class_collision
-    content = capture(:stderr){ run_generator ["object"] }
+    content = capture(:stderr) { run_generator ["object"] }
     assert_match(/The name 'Object' is either already used in your application or reserved/, content)
   end
 
@@ -386,7 +380,7 @@ class ModelGeneratorTest < Rails::Generators::TestCase
     run_generator ["account", "supplier:references{required}"]
 
     expected_file = <<-FILE.strip_heredoc
-    class Account < ActiveRecord::Base
+    class Account < ApplicationRecord
       belongs_to :supplier, required: true
     end
     FILE
@@ -397,7 +391,7 @@ class ModelGeneratorTest < Rails::Generators::TestCase
     run_generator ["account", "supplier:references{required,polymorphic}"]
 
     expected_file = <<-FILE.strip_heredoc
-    class Account < ActiveRecord::Base
+    class Account < ApplicationRecord
       belongs_to :supplier, polymorphic: true, required: true
     end
     FILE
@@ -408,7 +402,7 @@ class ModelGeneratorTest < Rails::Generators::TestCase
     run_generator ["account", "supplier:references{polymorphic.required}"]
 
     expected_file = <<-FILE.strip_heredoc
-    class Account < ActiveRecord::Base
+    class Account < ApplicationRecord
       belongs_to :supplier, polymorphic: true, required: true
     end
     FILE
@@ -459,7 +453,7 @@ class ModelGeneratorTest < Rails::Generators::TestCase
   def test_token_option_adds_has_secure_token
     run_generator ["user", "token:token", "auth_token:token"]
     expected_file = <<-FILE.strip_heredoc
-    class User < ActiveRecord::Base
+    class User < ApplicationRecord
       has_secure_token
       has_secure_token :auth_token
     end
diff --git a/railties/test/generators/named_base_test.rb b/railties/test/generators/named_base_test.rb
index 291f5e06c3..4e61b660d7 100644
--- a/railties/test/generators/named_base_test.rb
+++ b/railties/test/generators/named_base_test.rb
@@ -1,84 +1,108 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/rails/scaffold_controller/scaffold_controller_generator'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/scaffold_controller/scaffold_controller_generator"
 
 class NamedBaseTest < Rails::Generators::TestCase
   include GeneratorsTestHelper
   tests Rails::Generators::ScaffoldControllerGenerator
 
   def test_named_generator_with_underscore
-    g = generator ['line_item']
-    assert_name g, 'line_item',  :name
+    g = generator ["line_item"]
+    assert_name g, "line_item",  :name
     assert_name g, %w(),         :class_path
-    assert_name g, 'LineItem',   :class_name
-    assert_name g, 'line_item',  :file_path
-    assert_name g, 'line_item',  :file_name
-    assert_name g, 'Line item',  :human_name
-    assert_name g, 'line_item',  :singular_name
-    assert_name g, 'line_items', :plural_name
-    assert_name g, 'line_item',  :i18n_scope
-    assert_name g, 'line_items', :table_name
+    assert_name g, "LineItem",   :class_name
+    assert_name g, "line_item",  :file_path
+    assert_name g, "line_item",  :file_name
+    assert_name g, "Line item",  :human_name
+    assert_name g, "line_item",  :singular_name
+    assert_name g, "line_items", :plural_name
+    assert_name g, "line_item",  :i18n_scope
+    assert_name g, "line_items", :table_name
   end
 
   def test_named_generator_attributes
-    g = generator ['admin/foo']
-    assert_name g, 'admin/foo',  :name
+    g = generator ["admin/foo"]
+    assert_name g, "admin/foo",  :name
     assert_name g, %w(admin),    :class_path
-    assert_name g, 'Admin::Foo', :class_name
-    assert_name g, 'admin/foo',  :file_path
-    assert_name g, 'foo',        :file_name
-    assert_name g, 'Foo',        :human_name
-    assert_name g, 'foo',        :singular_name
-    assert_name g, 'foos',       :plural_name
-    assert_name g, 'admin.foo',  :i18n_scope
-    assert_name g, 'admin_foos', :table_name
+    assert_name g, "Admin::Foo", :class_name
+    assert_name g, "admin/foo",  :file_path
+    assert_name g, "foo",        :file_name
+    assert_name g, "Foo",        :human_name
+    assert_name g, "foo",        :singular_name
+    assert_name g, "foos",       :plural_name
+    assert_name g, "admin.foo",  :i18n_scope
+    assert_name g, "admin_foos", :table_name
+    assert_name g, "admin/foos", :controller_name
+    assert_name g, %w(admin),     :controller_class_path
+    assert_name g, "Admin::Foos", :controller_class_name
+    assert_name g, "admin/foos",  :controller_file_path
+    assert_name g, "foos",        :controller_file_name
+    assert_name g, "admin.foos",  :controller_i18n_scope
+    assert_name g, "admin_foo",  :singular_route_name
+    assert_name g, "admin_foos", :plural_route_name
+    assert_name g, "@admin_foo", :redirect_resource_name
+    assert_name g, "admin_foo",  :model_resource_name
+    assert_name g, "admin_foos", :index_helper
   end
 
   def test_named_generator_attributes_as_ruby
-    g = generator ['Admin::Foo']
-    assert_name g, 'Admin::Foo', :name
+    g = generator ["Admin::Foo"]
+    assert_name g, "Admin::Foo", :name
     assert_name g, %w(admin),    :class_path
-    assert_name g, 'Admin::Foo', :class_name
-    assert_name g, 'admin/foo',  :file_path
-    assert_name g, 'foo',        :file_name
-    assert_name g, 'foo',        :singular_name
-    assert_name g, 'Foo',        :human_name
-    assert_name g, 'foos',       :plural_name
-    assert_name g, 'admin.foo',  :i18n_scope
-    assert_name g, 'admin_foos', :table_name
+    assert_name g, "Admin::Foo", :class_name
+    assert_name g, "admin/foo",  :file_path
+    assert_name g, "foo",        :file_name
+    assert_name g, "foo",        :singular_name
+    assert_name g, "Foo",        :human_name
+    assert_name g, "foos",       :plural_name
+    assert_name g, "admin.foo",  :i18n_scope
+    assert_name g, "admin_foos", :table_name
+    assert_name g, "Admin::Foos", :controller_name
+    assert_name g, %w(admin),     :controller_class_path
+    assert_name g, "Admin::Foos", :controller_class_name
+    assert_name g, "admin/foos",  :controller_file_path
+    assert_name g, "foos",        :controller_file_name
+    assert_name g, "admin.foos",  :controller_i18n_scope
+    assert_name g, "admin_foo",  :singular_route_name
+    assert_name g, "admin_foos", :plural_route_name
+    assert_name g, "@admin_foo", :redirect_resource_name
+    assert_name g, "admin_foo",  :model_resource_name
+    assert_name g, "admin_foos", :index_helper
   end
 
   def test_named_generator_attributes_without_pluralized
     original_pluralize_table_names = ActiveRecord::Base.pluralize_table_names
     ActiveRecord::Base.pluralize_table_names = false
 
-    g = generator ['admin/foo']
-    assert_name g, 'admin_foo', :table_name
+    g = generator ["admin/foo"]
+    assert_name g, "admin_foo", :table_name
   ensure
     ActiveRecord::Base.pluralize_table_names = original_pluralize_table_names
   end
 
-  def test_scaffold_plural_names
-    g = generator ['admin/foo']
-    assert_name g, 'admin/foos',  :controller_name
+  def test_namespaced_scaffold_plural_names
+    g = generator ["admin/foo"]
+    assert_name g, "admin/foos",  :controller_name
     assert_name g, %w(admin),     :controller_class_path
-    assert_name g, 'Admin::Foos', :controller_class_name
-    assert_name g, 'admin/foos',  :controller_file_path
-    assert_name g, 'foos',        :controller_file_name
-    assert_name g, 'admin.foos',  :controller_i18n_scope
+    assert_name g, "Admin::Foos", :controller_class_name
+    assert_name g, "admin/foos",  :controller_file_path
+    assert_name g, "foos",        :controller_file_name
+    assert_name g, "admin.foos",  :controller_i18n_scope
   end
 
-  def test_scaffold_plural_names_as_ruby
-    g = generator ['Admin::Foo']
-    assert_name g, 'Admin::Foos', :controller_name
+  def test_namespaced_scaffold_plural_names_as_ruby
+    g = generator ["Admin::Foo"]
+    assert_name g, "Admin::Foos", :controller_name
     assert_name g, %w(admin),     :controller_class_path
-    assert_name g, 'Admin::Foos', :controller_class_name
-    assert_name g, 'admin/foos',  :controller_file_path
-    assert_name g, 'foos',        :controller_file_name
-    assert_name g, 'admin.foos',  :controller_i18n_scope
+    assert_name g, "Admin::Foos", :controller_class_name
+    assert_name g, "admin/foos",  :controller_file_path
+    assert_name g, "foos",        :controller_file_name
+    assert_name g, "admin.foos",  :controller_i18n_scope
   end
 
   def test_application_name
-    g = generator ['Admin::Foo']
+    g = generator ["Admin::Foo"]
     Rails.stub(:application, Object.new) do
       assert_name g, "object", :application_name
     end
@@ -89,49 +113,62 @@ class NamedBaseTest < Rails::Generators::TestCase
   end
 
   def test_index_helper
-    g = generator ['Post']
-    assert_name g, 'posts', :index_helper
+    g = generator ["Post"]
+    assert_name g, "posts", :index_helper
   end
 
   def test_index_helper_to_pluralize_once
-    g = generator ['Stadium']
-    assert_name g, 'stadia', :index_helper
+    g = generator ["Stadium"]
+    assert_name g, "stadia", :index_helper
   end
 
   def test_index_helper_with_uncountable
-    g = generator ['Sheep']
-    assert_name g, 'sheep_index', :index_helper
+    g = generator ["Sheep"]
+    assert_name g, "sheep_index", :index_helper
   end
 
   def test_hide_namespace
-    g = generator ['Hidden']
-    g.class.stub(:namespace, 'hidden') do
-      assert !Rails::Generators.hidden_namespaces.include?('hidden')
+    g = generator ["Hidden"]
+    g.class.stub(:namespace, "hidden") do
+      assert_not_includes Rails::Generators.hidden_namespaces, "hidden"
       g.class.hide!
-      assert Rails::Generators.hidden_namespaces.include?('hidden')
+      assert_includes Rails::Generators.hidden_namespaces, "hidden"
     end
   end
 
   def test_scaffold_plural_names_with_model_name_option
-    g = generator ['Admin::Foo'], model_name: 'User'
-    assert_name g, 'user',        :singular_name
-    assert_name g, 'User',        :name
-    assert_name g, 'user',        :file_path
-    assert_name g, 'User',        :class_name
-    assert_name g, 'user',        :file_name
-    assert_name g, 'User',        :human_name
-    assert_name g, 'users',       :plural_name
-    assert_name g, 'user',        :i18n_scope
-    assert_name g, 'users',       :table_name
-    assert_name g, 'Admin::Foos', :controller_name
+    g = generator ["Admin::Foo"], model_name: "User"
+    assert_name g, "user",        :singular_name
+    assert_name g, "User",        :name
+    assert_name g, "user",        :file_path
+    assert_name g, "User",        :class_name
+    assert_name g, "user",        :file_name
+    assert_name g, "User",        :human_name
+    assert_name g, "users",       :plural_name
+    assert_name g, "user",        :i18n_scope
+    assert_name g, "users",       :table_name
+    assert_name g, "Admin::Foos", :controller_name
     assert_name g, %w(admin),     :controller_class_path
-    assert_name g, 'Admin::Foos', :controller_class_name
-    assert_name g, 'admin/foos',  :controller_file_path
-    assert_name g, 'foos',        :controller_file_name
-    assert_name g, 'admin.foos',  :controller_i18n_scope
+    assert_name g, "Admin::Foos", :controller_class_name
+    assert_name g, "admin/foos",  :controller_file_path
+    assert_name g, "foos",        :controller_file_name
+    assert_name g, "admin.foos",  :controller_i18n_scope
+    assert_name g, "admin_user",  :singular_route_name
+    assert_name g, "admin_users", :plural_route_name
+    assert_name g, "[:admin, @user]", :redirect_resource_name
+    assert_name g, "[:admin, user]",  :model_resource_name
+    assert_name g, "admin_users", :index_helper
+  end
+
+  def test_scaffold_plural_names
+    g = generator ["User"]
+    assert_name g, "@user", :redirect_resource_name
+    assert_name g, "user",  :model_resource_name
+    assert_name g, "user",  :singular_route_name
+    assert_name g, "users", :plural_route_name
   end
 
-  protected
+  private
 
     def assert_name(generator, value, method)
       assert_equal value, generator.send(method)
diff --git a/railties/test/generators/namespaced_generators_test.rb b/railties/test/generators/namespaced_generators_test.rb
index d76759a7d1..4b75a31f17 100644
--- a/railties/test/generators/namespaced_generators_test.rb
+++ b/railties/test/generators/namespaced_generators_test.rb
@@ -1,8 +1,11 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/rails/controller/controller_generator'
-require 'rails/generators/rails/model/model_generator'
-require 'rails/generators/mailer/mailer_generator'
-require 'rails/generators/rails/scaffold/scaffold_generator'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/controller/controller_generator"
+require "rails/generators/rails/model/model_generator"
+require "rails/generators/mailer/mailer_generator"
+require "rails/generators/rails/scaffold/scaffold_generator"
+require "rails/generators/rails/application_record/application_record_generator"
 
 class NamespacedGeneratorTestCase < Rails::Generators::TestCase
   include GeneratorsTestHelper
@@ -91,7 +94,7 @@ class NamespacedModelGeneratorTest < NamespacedGeneratorTestCase
 
   def test_adds_namespace_to_model
     run_generator
-    assert_file "app/models/test_app/account.rb", /module TestApp/, /  class Account < ActiveRecord::Base/
+    assert_file "app/models/test_app/account.rb", /module TestApp/, /  class Account < ApplicationRecord/
   end
 
   def test_model_with_namespace
@@ -99,7 +102,7 @@ class NamespacedModelGeneratorTest < NamespacedGeneratorTestCase
     assert_file "app/models/test_app/admin.rb", /module TestApp/, /module Admin/
     assert_file "app/models/test_app/admin.rb", /def self\.table_name_prefix/
     assert_file "app/models/test_app/admin.rb", /'test_app_admin_'/
-    assert_file "app/models/test_app/admin/account.rb", /module TestApp/, /class Admin::Account < ActiveRecord::Base/
+    assert_file "app/models/test_app/admin/account.rb", /module TestApp/, /class Admin::Account < ApplicationRecord/
   end
 
   def test_migration
@@ -149,7 +152,7 @@ class NamespacedMailerGeneratorTest < NamespacedGeneratorTestCase
     assert_file "app/mailers/test_app/notifier_mailer.rb" do |mailer|
       assert_match(/module TestApp/, mailer)
       assert_match(/class NotifierMailer < ApplicationMailer/, mailer)
-      assert_no_match(/default from: "from@example.com"/, mailer)
+      assert_no_match(/default from: "from@example\.com"/, mailer)
     end
   end
 
@@ -201,7 +204,7 @@ class NamespacedScaffoldGeneratorTest < NamespacedGeneratorTestCase
     run_generator
 
     # Model
-    assert_file "app/models/test_app/product_line.rb", /module TestApp\n  class ProductLine < ActiveRecord::Base/
+    assert_file "app/models/test_app/product_line.rb", /module TestApp\n  class ProductLine < ApplicationRecord/
     assert_file "test/models/test_app/product_line_test.rb", /module TestApp\n  class ProductLineTest < ActiveSupport::TestCase/
     assert_file "test/fixtures/test_app/product_lines.yml"
     assert_migration "db/migrate/create_test_app_product_lines.rb"
@@ -268,7 +271,7 @@ class NamespacedScaffoldGeneratorTest < NamespacedGeneratorTestCase
 
     # Model
     assert_file "app/models/test_app/admin.rb", /module TestApp\n  module Admin/
-    assert_file "app/models/test_app/admin/role.rb", /module TestApp\n  class Admin::Role < ActiveRecord::Base/
+    assert_file "app/models/test_app/admin/role.rb", /module TestApp\n  class Admin::Role < ApplicationRecord/
     assert_file "test/models/test_app/admin/role_test.rb", /module TestApp\n  class Admin::RoleTest < ActiveSupport::TestCase/
     assert_file "test/fixtures/test_app/admin/roles.yml"
     assert_migration "db/migrate/create_test_app_admin_roles.rb"
@@ -336,7 +339,7 @@ class NamespacedScaffoldGeneratorTest < NamespacedGeneratorTestCase
 
     # Model
     assert_file "app/models/test_app/admin/user/special.rb", /module TestApp\n  module Admin/
-    assert_file "app/models/test_app/admin/user/special/role.rb", /module TestApp\n  class Admin::User::Special::Role < ActiveRecord::Base/
+    assert_file "app/models/test_app/admin/user/special/role.rb", /module TestApp\n  class Admin::User::Special::Role < ApplicationRecord/
     assert_file "test/models/test_app/admin/user/special/role_test.rb", /module TestApp\n  class Admin::User::Special::RoleTest < ActiveSupport::TestCase/
     assert_file "test/fixtures/test_app/admin/user/special/roles.yml"
     assert_migration "db/migrate/create_test_app_admin_user_special_roles.rb"
@@ -402,7 +405,7 @@ class NamespacedScaffoldGeneratorTest < NamespacedGeneratorTestCase
 
     # Model
     assert_file "app/models/test_app/admin.rb", /module TestApp\n  module Admin/
-    assert_file "app/models/test_app/admin/role.rb", /module TestApp\n  class Admin::Role < ActiveRecord::Base/
+    assert_file "app/models/test_app/admin/role.rb", /module TestApp\n  class Admin::Role < ApplicationRecord/
     assert_file "test/models/test_app/admin/role_test.rb", /module TestApp\n  class Admin::RoleTest < ActiveSupport::TestCase/
     assert_file "test/fixtures/test_app/admin/roles.yml"
     assert_migration "db/migrate/create_test_app_admin_roles.rb"
@@ -421,3 +424,13 @@ class NamespacedScaffoldGeneratorTest < NamespacedGeneratorTestCase
                 /module TestApp\n  class Admin::RolesControllerTest < ActionDispatch::IntegrationTest/
   end
 end
+
+class NamespacedApplicationRecordGeneratorTest < NamespacedGeneratorTestCase
+  include GeneratorsTestHelper
+  tests Rails::Generators::ApplicationRecordGenerator
+
+  def test_adds_namespace_to_application_record
+    run_generator
+    assert_file "app/models/test_app/application_record.rb", /module TestApp/, /  class ApplicationRecord < ActiveRecord::Base/
+  end
+end
diff --git a/railties/test/generators/orm_test.rb b/railties/test/generators/orm_test.rb
index 88ae930554..6eaf2fbfd3 100644
--- a/railties/test/generators/orm_test.rb
+++ b/railties/test/generators/orm_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "generators/generators_test_helper"
 require "rails/generators/rails/scaffold_controller/scaffold_controller_generator"
 
diff --git a/railties/test/generators/plugin_generator_test.rb b/railties/test/generators/plugin_generator_test.rb
index 3cc8e1de55..38130ceb68 100644
--- a/railties/test/generators/plugin_generator_test.rb
+++ b/railties/test/generators/plugin_generator_test.rb
@@ -1,6 +1,9 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/rails/plugin/plugin_generator'
-require 'generators/shared_generator_tests'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/plugin/plugin_generator"
+require "generators/shared_generator_tests"
+require "rails/engine/updater"
 
 DEFAULT_PLUGIN_FILES = %w(
   .gitignore
@@ -23,23 +26,27 @@ class PluginGeneratorTest < Rails::Generators::TestCase
   destination File.join(Rails.root, "tmp/bukkits")
   arguments [destination_root]
 
+  def application_path
+    "#{destination_root}/test/dummy"
+  end
+
   # brings setup, teardown, and some tests
   include SharedGeneratorTests
 
   def test_invalid_plugin_name_raises_an_error
-    content = capture(:stderr){ run_generator [File.join(destination_root, "my_plugin-31fr-extension")] }
+    content = capture(:stderr) { run_generator [File.join(destination_root, "my_plugin-31fr-extension")] }
     assert_equal "Invalid plugin name my_plugin-31fr-extension. Please give a name which does not contain a namespace starting with numeric characters.\n", content
 
-    content = capture(:stderr){ run_generator [File.join(destination_root, "things4.3")] }
+    content = capture(:stderr) { run_generator [File.join(destination_root, "things4.3")] }
     assert_equal "Invalid plugin name things4.3. Please give a name which uses only alphabetic, numeric, \"_\" or \"-\" characters.\n", content
 
-    content = capture(:stderr){ run_generator [File.join(destination_root, "43things")] }
+    content = capture(:stderr) { run_generator [File.join(destination_root, "43things")] }
     assert_equal "Invalid plugin name 43things. Please give a name which does not start with numbers.\n", content
 
-    content = capture(:stderr){ run_generator [File.join(destination_root, "plugin")] }
+    content = capture(:stderr) { run_generator [File.join(destination_root, "plugin")] }
     assert_equal "Invalid plugin name plugin. Please give a name which does not match one of the reserved rails words: application, destroy, plugin, runner, test\n", content
 
-    content = capture(:stderr){ run_generator [File.join(destination_root, "Digest")] }
+    content = capture(:stderr) { run_generator [File.join(destination_root, "Digest")] }
     assert_equal "Invalid plugin name Digest, constant Digest is already in use. Please choose another plugin name.\n", content
   end
 
@@ -47,7 +54,7 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     run_generator [File.join(destination_root, "hyphenated-name")]
     assert_no_file "hyphenated-name/lib/hyphenated-name.rb"
     assert_no_file "hyphenated-name/lib/hyphenated_name.rb"
-    assert_file "hyphenated-name/lib/hyphenated/name.rb", /module Hyphenated\n  module Name\n    # Your code goes here...\n  end\nend/
+    assert_file "hyphenated-name/lib/hyphenated/name.rb", /module Hyphenated\n  module Name\n    # Your code goes here\.\.\.\n  end\nend/
   end
 
   def test_correct_file_in_lib_folder_of_camelcase_plugin_name
@@ -62,14 +69,28 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     assert_no_file "config/routes.rb"
     assert_no_file "app/assets/config/bukkits_manifest.js"
     assert_file "test/test_helper.rb" do |content|
-      assert_match(/require.+test\/dummy\/config\/environment/, content)
+      assert_match(/require_relative.+test\/dummy\/config\/environment/, content)
       assert_match(/ActiveRecord::Migrator\.migrations_paths.+test\/dummy\/db\/migrate/, content)
       assert_match(/Minitest\.backtrace_filter = Minitest::BacktraceFilter\.new/, content)
       assert_match(/Rails::TestUnitReporter\.executable = 'bin\/test'/, content)
     end
+    assert_file "lib/bukkits/railtie.rb", /module Bukkits\n  class Railtie < ::Rails::Railtie\n  end\nend/
+    assert_file "lib/bukkits.rb", /require "bukkits\/railtie"/
     assert_file "test/bukkits_test.rb", /assert_kind_of Module, Bukkits/
-    assert_file 'bin/test'
-    assert_no_file 'bin/rails'
+    assert_file "bin/test"
+    assert_no_file "bin/rails"
+  end
+
+  def test_generating_in_full_mode_with_almost_of_all_skip_options
+    run_generator [destination_root, "--full", "-M", "-O", "-C", "-S", "-T"]
+    assert_file "bin/rails" do |content|
+      assert_no_match(/\s+require\s+["']rails\/all["']/, content)
+    end
+    assert_file "bin/rails", /#\s+require\s+["']active_record\/railtie["']/
+    assert_file "bin/rails", /#\s+require\s+["']action_mailer\/railtie["']/
+    assert_file "bin/rails", /#\s+require\s+["']action_cable\/engine["']/
+    assert_file "bin/rails", /#\s+require\s+["']sprockets\/railtie["']/
+    assert_file "bin/rails", /#\s+require\s+["']rails\/test_unit\/railtie["']/
   end
 
   def test_generating_test_files_in_full_mode
@@ -79,8 +100,13 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     assert_file "test/integration/navigation_test.rb", /ActionDispatch::IntegrationTest/
   end
 
+  def test_inclusion_of_git_source
+    run_generator [destination_root]
+    assert_file "Gemfile", /git_source/
+  end
+
   def test_inclusion_of_a_debugger
-    run_generator [destination_root, '--full']
+    run_generator [destination_root, "--full"]
     if defined?(JRUBY_VERSION) || RUBY_ENGINE == "rbx"
       assert_file "Gemfile" do |content|
         assert_no_match(/byebug/, content)
@@ -94,15 +120,19 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     run_generator [destination_root, "-T", "--full"]
 
     assert_no_directory "test/integration/"
-    assert_no_file "test"
+    assert_no_directory "test"
     assert_file "Rakefile" do |contents|
       assert_no_match(/APP_RAKEFILE/, contents)
     end
+    assert_file "bin/rails" do |contents|
+      assert_no_match(/APP_PATH/, contents)
+    end
   end
 
   def test_generating_adds_dummy_app_rake_tasks_without_unit_test_files
-    run_generator [destination_root, "-T", "--mountable", '--dummy-path', 'my_dummy_app']
+    run_generator [destination_root, "-T", "--mountable", "--dummy-path", "my_dummy_app"]
     assert_file "Rakefile", /APP_RAKEFILE/
+    assert_file "bin/rails", /APP_PATH/
   end
 
   def test_generating_adds_dummy_app_without_javascript_and_assets_deps
@@ -123,8 +153,8 @@ class PluginGeneratorTest < Rails::Generators::TestCase
   def test_ensure_that_test_dummy_can_be_generated_from_a_template
     FileUtils.cd(Rails.root)
     run_generator([destination_root, "-m", "lib/create_test_dummy_template.rb", "--skip-test"])
-    assert_file "spec/dummy"
-    assert_no_file "test"
+    assert_directory "spec/dummy"
+    assert_no_directory "test"
   end
 
   def test_database_entry_is_generated_for_sqlite3_by_default_in_full_mode
@@ -143,63 +173,40 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     run_generator [destination_root, "--skip-active-record"]
 
     assert_file "bukkits.gemspec" do |contents|
-      assert_no_match(/s.add_development_dependency "sqlite3"/, contents)
+      assert_no_match(/s\.add_development_dependency "sqlite3"/, contents)
     end
   end
 
-  def test_app_generator_without_skips
-    run_generator
-    assert_file "test/dummy/config/application.rb", /\s+require\s+["']rails\/all["']/
-    assert_file "test/dummy/config/environments/development.rb" do |content|
-      assert_match(/config\.action_mailer\.raise_delivery_errors = false/, content)
-    end
-    assert_file "test/dummy/config/environments/test.rb" do |content|
-      assert_match(/config\.action_mailer\.delivery_method = :test/, content)
-    end
-    assert_file "test/dummy/config/environments/production.rb" do |content|
-      assert_match(/# config\.action_mailer\.raise_delivery_errors = false/, content)
-    end
-  end
-
-  def test_active_record_is_removed_from_frameworks_if_skip_active_record_is_given
-    run_generator [destination_root, "--skip-active-record"]
-    assert_file "test/dummy/config/application.rb", /#\s+require\s+["']active_record\/railtie["']/
-  end
-
   def test_ensure_that_skip_active_record_option_is_passed_to_app_generator
     run_generator [destination_root, "--skip_active_record"]
-    assert_no_file "test/dummy/config/database.yml"
     assert_file "test/test_helper.rb" do |contents|
       assert_no_match(/ActiveRecord/, contents)
     end
   end
 
-  def test_action_mailer_is_removed_from_frameworks_if_skip_action_mailer_is_given
-    run_generator [destination_root, "--skip-action-mailer"]
-    assert_file "test/dummy/config/application.rb", /#\s+require\s+["']action_mailer\/railtie["']/
-    assert_file "test/dummy/config/environments/development.rb" do |content|
-      assert_no_match(/config\.action_mailer/, content)
-    end
-    assert_file "test/dummy/config/environments/test.rb" do |content|
-      assert_no_match(/config\.action_mailer/, content)
-    end
-    assert_file "test/dummy/config/environments/production.rb" do |content|
-      assert_no_match(/config\.action_mailer/, content)
-    end
-  end
-
   def test_ensure_that_database_option_is_passed_to_app_generator
     run_generator [destination_root, "--database", "postgresql"]
     assert_file "test/dummy/config/database.yml", /postgres/
   end
 
-  def test_generation_runs_bundle_install_with_full_and_mountable
-    result = run_generator [destination_root, "--mountable", "--full", "--dev"]
-    assert_match(/run  bundle install/, result)
-    assert $?.success?, "Command failed: #{result}"
-    assert_file "#{destination_root}/Gemfile.lock" do |contents|
-      assert_match(/bukkits/, contents)
-    end
+  def test_generation_runs_bundle_install
+    assert_generates_without_bundler
+  end
+
+  def test_dev_option
+    assert_generates_without_bundler(dev: true)
+    rails_path = File.expand_path("../../..", Rails.root)
+    assert_file "Gemfile", /^gem\s+["']rails["'],\s+path:\s+["']#{Regexp.escape(rails_path)}["']$/
+  end
+
+  def test_edge_option
+    assert_generates_without_bundler(edge: true)
+    assert_file "Gemfile", %r{^gem\s+["']rails["'],\s+github:\s+["']#{Regexp.escape("rails/rails")}["']$}
+  end
+
+  def test_generation_does_not_run_bundle_install_with_full_and_mountable
+    assert_generates_without_bundler(mountable: true, full: true, dev: true)
+    assert_no_file "#{destination_root}/Gemfile.lock"
   end
 
   def test_skipping_javascripts_without_mountable_option
@@ -225,21 +232,22 @@ class PluginGeneratorTest < Rails::Generators::TestCase
   def test_ensure_that_tests_work
     run_generator
     FileUtils.cd destination_root
-    quietly { system 'bundle install' }
+    quietly { system "bundle install" }
     assert_match(/1 runs, 1 assertions, 0 failures, 0 errors/, `bin/test 2>&1`)
   end
 
   def test_ensure_that_tests_works_in_full_mode
     run_generator [destination_root, "--full", "--skip_active_record"]
     FileUtils.cd destination_root
-    quietly { system 'bundle install' }
-    assert_match(/1 runs, 1 assertions, 0 failures, 0 errors/, `bundle exec rake test 2>&1`)
+    quietly { system "bundle install" }
+    # FIXME: Active Storage will provoke a test error without ActiveRecord (fix by allowing to skip active storage)
+    assert_match(/1 runs, 0 assertions, 0 failures, 1 errors/, `bundle exec rake test 2>&1`)
   end
 
   def test_ensure_that_migration_tasks_work_with_mountable_option
     run_generator [destination_root, "--mountable"]
     FileUtils.cd destination_root
-    quietly { system 'bundle install' }
+    quietly { system "bundle install" }
     output = `bin/rails db:migrate 2>&1`
     assert $?.success?, "Command failed: #{output}"
   end
@@ -254,7 +262,7 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     assert_file "app/views"
     assert_file "app/helpers"
     assert_file "app/mailers"
-    assert_file "bin/rails"
+    assert_file "bin/rails", /\s+require\s+["']rails\/all["']/
     assert_file "config/routes.rb", /Rails.application.routes.draw do/
     assert_file "lib/bukkits/engine.rb", /module Bukkits\n  class Engine < ::Rails::Engine\n  end\nend/
     assert_file "lib/bukkits.rb", /require "bukkits\/engine"/
@@ -274,7 +282,7 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     assert_file "hyphenated-name/config/routes.rb",              /Rails.application.routes.draw do/
     assert_file "hyphenated-name/lib/hyphenated/name/engine.rb", /module Hyphenated\n  module Name\n    class Engine < ::Rails::Engine\n    end\n  end\nend/
     assert_file "hyphenated-name/lib/hyphenated/name.rb",        /require "hyphenated\/name\/engine"/
-    assert_file "hyphenated-name/bin/rails",                     /\.\.\/\.\.\/lib\/hyphenated\/name\/engine/
+    assert_file "hyphenated-name/bin/rails",                     /\.\.\/lib\/hyphenated\/name\/engine/
   end
 
   def test_creating_engine_with_hyphenated_and_underscored_name_in_full_mode
@@ -288,14 +296,14 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     assert_file "my_hyphenated-name/app/helpers"
     assert_file "my_hyphenated-name/app/mailers"
     assert_file "my_hyphenated-name/bin/rails"
-    assert_file "my_hyphenated-name/config/routes.rb",              /Rails.application.routes.draw do/
+    assert_file "my_hyphenated-name/config/routes.rb",              /Rails\.application\.routes\.draw do/
     assert_file "my_hyphenated-name/lib/my_hyphenated/name/engine.rb", /module MyHyphenated\n  module Name\n    class Engine < ::Rails::Engine\n    end\n  end\nend/
     assert_file "my_hyphenated-name/lib/my_hyphenated/name.rb",        /require "my_hyphenated\/name\/engine"/
-    assert_file "my_hyphenated-name/bin/rails",                     /\.\.\/\.\.\/lib\/my_hyphenated\/name\/engine/
+    assert_file "my_hyphenated-name/bin/rails",                     /\.\.\/lib\/my_hyphenated\/name\/engine/
   end
 
   def test_being_quiet_while_creating_dummy_application
-    assert_no_match(/create\s+config\/application.rb/, run_generator)
+    assert_no_match(/create\s+config\/application\.rb/, run_generator)
   end
 
   def test_create_mountable_application_with_mountable_option
@@ -303,13 +311,13 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     assert_file "app/assets/javascripts/bukkits"
     assert_file "app/assets/stylesheets/bukkits"
     assert_file "app/assets/images/bukkits"
-    assert_file "config/routes.rb", /Bukkits::Engine.routes.draw do/
+    assert_file "config/routes.rb", /Bukkits::Engine\.routes\.draw do/
     assert_file "lib/bukkits/engine.rb", /isolate_namespace Bukkits/
     assert_file "test/dummy/config/routes.rb", /mount Bukkits::Engine => "\/bukkits"/
     assert_file "app/controllers/bukkits/application_controller.rb", /module Bukkits\n  class ApplicationController < ActionController::Base/
     assert_file "app/models/bukkits/application_record.rb", /module Bukkits\n  class ApplicationRecord < ActiveRecord::Base/
     assert_file "app/jobs/bukkits/application_job.rb", /module Bukkits\n  class ApplicationJob < ActiveJob::Base/
-    assert_file "app/mailers/bukkits/application_mailer.rb", /module Bukkits\n  class ApplicationMailer < ActionMailer::Base\n    default from: 'from@example.com'\n    layout 'mailer'\n/
+    assert_file "app/mailers/bukkits/application_mailer.rb", /module Bukkits\n  class ApplicationMailer < ActionMailer::Base\n    default from: 'from@example\.com'\n    layout 'mailer'\n/
     assert_file "app/helpers/bukkits/application_helper.rb", /module Bukkits\n  module ApplicationHelper/
     assert_file "app/views/layouts/bukkits/application.html.erb" do |contents|
       assert_match "<title>Bukkits</title>", contents
@@ -322,7 +330,7 @@ class PluginGeneratorTest < Rails::Generators::TestCase
       assert_match(/ActionDispatch::IntegrationTest\.fixture_path = ActiveSupport::TestCase\.fixture_pat/, content)
       assert_no_match(/Rails::TestUnitReporter\.executable = 'bin\/test'/, content)
     end
-    assert_no_file 'bin/test'
+    assert_no_file "bin/test"
   end
 
   def test_create_mountable_application_with_mountable_option_and_hypenated_name
@@ -330,15 +338,15 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     assert_file "hyphenated-name/app/assets/javascripts/hyphenated/name"
     assert_file "hyphenated-name/app/assets/stylesheets/hyphenated/name"
     assert_file "hyphenated-name/app/assets/images/hyphenated/name"
-    assert_file "hyphenated-name/config/routes.rb",                                          /Hyphenated::Name::Engine.routes.draw do/
-    assert_file "hyphenated-name/lib/hyphenated/name/version.rb",                            /module Hyphenated\n  module Name\n    VERSION = '0.1.0'\n  end\nend/
+    assert_file "hyphenated-name/config/routes.rb",                                          /Hyphenated::Name::Engine\.routes\.draw do/
+    assert_file "hyphenated-name/lib/hyphenated/name/version.rb",                            /module Hyphenated\n  module Name\n    VERSION = '0\.1\.0'\n  end\nend/
     assert_file "hyphenated-name/lib/hyphenated/name/engine.rb",                             /module Hyphenated\n  module Name\n    class Engine < ::Rails::Engine\n      isolate_namespace Hyphenated::Name\n    end\n  end\nend/
     assert_file "hyphenated-name/lib/hyphenated/name.rb",                                    /require "hyphenated\/name\/engine"/
     assert_file "hyphenated-name/test/dummy/config/routes.rb",                               /mount Hyphenated::Name::Engine => "\/hyphenated-name"/
     assert_file "hyphenated-name/app/controllers/hyphenated/name/application_controller.rb", /module Hyphenated\n  module Name\n    class ApplicationController < ActionController::Base\n      protect_from_forgery with: :exception\n    end\n  end\nend\n/
     assert_file "hyphenated-name/app/models/hyphenated/name/application_record.rb",          /module Hyphenated\n  module Name\n    class ApplicationRecord < ActiveRecord::Base\n      self\.abstract_class = true\n    end\n  end\nend/
     assert_file "hyphenated-name/app/jobs/hyphenated/name/application_job.rb",               /module Hyphenated\n  module Name\n    class ApplicationJob < ActiveJob::Base/
-    assert_file "hyphenated-name/app/mailers/hyphenated/name/application_mailer.rb",         /module Hyphenated\n  module Name\n    class ApplicationMailer < ActionMailer::Base\n      default from: 'from@example.com'\n      layout 'mailer'\n    end\n  end\nend/
+    assert_file "hyphenated-name/app/mailers/hyphenated/name/application_mailer.rb",         /module Hyphenated\n  module Name\n    class ApplicationMailer < ActionMailer::Base\n      default from: 'from@example\.com'\n      layout 'mailer'\n    end\n  end\nend/
     assert_file "hyphenated-name/app/helpers/hyphenated/name/application_helper.rb",         /module Hyphenated\n  module Name\n    module ApplicationHelper\n    end\n  end\nend/
     assert_file "hyphenated-name/app/views/layouts/hyphenated/name/application.html.erb" do |contents|
       assert_match "<title>Hyphenated name</title>", contents
@@ -352,15 +360,15 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     assert_file "my_hyphenated-name/app/assets/javascripts/my_hyphenated/name"
     assert_file "my_hyphenated-name/app/assets/stylesheets/my_hyphenated/name"
     assert_file "my_hyphenated-name/app/assets/images/my_hyphenated/name"
-    assert_file "my_hyphenated-name/config/routes.rb",                                             /MyHyphenated::Name::Engine.routes.draw do/
-    assert_file "my_hyphenated-name/lib/my_hyphenated/name/version.rb",                            /module MyHyphenated\n  module Name\n    VERSION = '0.1.0'\n  end\nend/
+    assert_file "my_hyphenated-name/config/routes.rb",                                             /MyHyphenated::Name::Engine\.routes\.draw do/
+    assert_file "my_hyphenated-name/lib/my_hyphenated/name/version.rb",                            /module MyHyphenated\n  module Name\n    VERSION = '0\.1\.0'\n  end\nend/
     assert_file "my_hyphenated-name/lib/my_hyphenated/name/engine.rb",                             /module MyHyphenated\n  module Name\n    class Engine < ::Rails::Engine\n      isolate_namespace MyHyphenated::Name\n    end\n  end\nend/
     assert_file "my_hyphenated-name/lib/my_hyphenated/name.rb",                                    /require "my_hyphenated\/name\/engine"/
     assert_file "my_hyphenated-name/test/dummy/config/routes.rb",                                  /mount MyHyphenated::Name::Engine => "\/my_hyphenated-name"/
     assert_file "my_hyphenated-name/app/controllers/my_hyphenated/name/application_controller.rb", /module MyHyphenated\n  module Name\n    class ApplicationController < ActionController::Base\n      protect_from_forgery with: :exception\n    end\n  end\nend\n/
     assert_file "my_hyphenated-name/app/models/my_hyphenated/name/application_record.rb",          /module MyHyphenated\n  module Name\n    class ApplicationRecord < ActiveRecord::Base\n      self\.abstract_class = true\n    end\n  end\nend/
     assert_file "my_hyphenated-name/app/jobs/my_hyphenated/name/application_job.rb",               /module MyHyphenated\n  module Name\n    class ApplicationJob < ActiveJob::Base/
-    assert_file "my_hyphenated-name/app/mailers/my_hyphenated/name/application_mailer.rb",         /module MyHyphenated\n  module Name\n    class ApplicationMailer < ActionMailer::Base\n      default from: 'from@example.com'\n      layout 'mailer'\n    end\n  end\nend/
+    assert_file "my_hyphenated-name/app/mailers/my_hyphenated/name/application_mailer.rb",         /module MyHyphenated\n  module Name\n    class ApplicationMailer < ActionMailer::Base\n      default from: 'from@example\.com'\n      layout 'mailer'\n    end\n  end\nend/
     assert_file "my_hyphenated-name/app/helpers/my_hyphenated/name/application_helper.rb",         /module MyHyphenated\n  module Name\n    module ApplicationHelper\n    end\n  end\nend/
     assert_file "my_hyphenated-name/app/views/layouts/my_hyphenated/name/application.html.erb" do |contents|
       assert_match "<title>My hyphenated name</title>", contents
@@ -374,15 +382,15 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     assert_file "deep-hyphenated-name/app/assets/javascripts/deep/hyphenated/name"
     assert_file "deep-hyphenated-name/app/assets/stylesheets/deep/hyphenated/name"
     assert_file "deep-hyphenated-name/app/assets/images/deep/hyphenated/name"
-    assert_file "deep-hyphenated-name/config/routes.rb",                                               /Deep::Hyphenated::Name::Engine.routes.draw do/
-    assert_file "deep-hyphenated-name/lib/deep/hyphenated/name/version.rb",                            /module Deep\n  module Hyphenated\n    module Name\n      VERSION = '0.1.0'\n    end\n  end\nend/
+    assert_file "deep-hyphenated-name/config/routes.rb",                                               /Deep::Hyphenated::Name::Engine\.routes\.draw do/
+    assert_file "deep-hyphenated-name/lib/deep/hyphenated/name/version.rb",                            /module Deep\n  module Hyphenated\n    module Name\n      VERSION = '0\.1\.0'\n    end\n  end\nend/
     assert_file "deep-hyphenated-name/lib/deep/hyphenated/name/engine.rb",                             /module Deep\n  module Hyphenated\n    module Name\n      class Engine < ::Rails::Engine\n        isolate_namespace Deep::Hyphenated::Name\n      end\n    end\n  end\nend/
     assert_file "deep-hyphenated-name/lib/deep/hyphenated/name.rb",                                    /require "deep\/hyphenated\/name\/engine"/
     assert_file "deep-hyphenated-name/test/dummy/config/routes.rb",                                    /mount Deep::Hyphenated::Name::Engine => "\/deep-hyphenated-name"/
     assert_file "deep-hyphenated-name/app/controllers/deep/hyphenated/name/application_controller.rb", /module Deep\n  module Hyphenated\n    module Name\n      class ApplicationController < ActionController::Base\n        protect_from_forgery with: :exception\n      end\n    end\n  end\nend\n/
     assert_file "deep-hyphenated-name/app/models/deep/hyphenated/name/application_record.rb",          /module Deep\n  module Hyphenated\n    module Name\n      class ApplicationRecord < ActiveRecord::Base\n        self\.abstract_class = true\n      end\n    end\n  end\nend/
     assert_file "deep-hyphenated-name/app/jobs/deep/hyphenated/name/application_job.rb",               /module Deep\n  module Hyphenated\n    module Name\n      class ApplicationJob < ActiveJob::Base/
-    assert_file "deep-hyphenated-name/app/mailers/deep/hyphenated/name/application_mailer.rb",         /module Deep\n  module Hyphenated\n    module Name\n      class ApplicationMailer < ActionMailer::Base\n        default from: 'from@example.com'\n        layout 'mailer'\n      end\n    end\n  end\nend/
+    assert_file "deep-hyphenated-name/app/mailers/deep/hyphenated/name/application_mailer.rb",         /module Deep\n  module Hyphenated\n    module Name\n      class ApplicationMailer < ActionMailer::Base\n        default from: 'from@example\.com'\n        layout 'mailer'\n      end\n    end\n  end\nend/
     assert_file "deep-hyphenated-name/app/helpers/deep/hyphenated/name/application_helper.rb",         /module Deep\n  module Hyphenated\n    module Name\n      module ApplicationHelper\n      end\n    end\n  end\nend/
     assert_file "deep-hyphenated-name/app/views/layouts/deep/hyphenated/name/application.html.erb" do |contents|
       assert_match "<title>Deep hyphenated name</title>", contents
@@ -393,15 +401,16 @@ class PluginGeneratorTest < Rails::Generators::TestCase
 
   def test_creating_gemspec
     run_generator
-    assert_file "bukkits.gemspec", /s.name\s+= "bukkits"/
-    assert_file "bukkits.gemspec", /s.files = Dir\["\{app,config,db,lib\}\/\*\*\/\*", "MIT-LICENSE", "Rakefile", "README\.md"\]/
-    assert_file "bukkits.gemspec", /s.version\s+ = Bukkits::VERSION/
+    assert_file "bukkits.gemspec", /s\.name\s+= "bukkits"/
+    assert_file "bukkits.gemspec", /s\.files = Dir\["\{app,config,db,lib\}\/\*\*\/\*", "MIT-LICENSE", "Rakefile", "README\.md"\]/
+    assert_file "bukkits.gemspec", /s\.version\s+ = Bukkits::VERSION/
   end
 
   def test_usage_of_engine_commands
     run_generator [destination_root, "--full"]
-    assert_file "bin/rails", /ENGINE_PATH = File.expand_path\('..\/..\/lib\/bukkits\/engine', __FILE__\)/
-    assert_file "bin/rails", /ENGINE_ROOT = File.expand_path\('..\/..', __FILE__\)/
+    assert_file "bin/rails", /ENGINE_PATH = File\.expand_path\('\.\.\/lib\/bukkits\/engine', __dir__\)/
+    assert_file "bin/rails", /ENGINE_ROOT = File\.expand_path\('\.\.', __dir__\)/
+    assert_file "bin/rails", %r|APP_PATH = File\.expand_path\('\.\./test/dummy/config/application', __dir__\)|
     assert_file "bin/rails", /require 'rails\/all'/
     assert_file "bin/rails", /require 'rails\/engine\/commands'/
   end
@@ -417,7 +426,7 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     assert_file "spec/dummy/config/application.rb"
     assert_no_file "test/dummy"
     assert_file "test/test_helper.rb" do |content|
-      assert_match(/require.+spec\/dummy\/config\/environment/, content)
+      assert_match(/require_relative.+spec\/dummy\/config\/environment/, content)
       assert_match(/ActiveRecord::Migrator\.migrations_paths.+spec\/dummy\/db\/migrate/, content)
     end
   end
@@ -428,18 +437,17 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     assert_file "spec/fake/config/application.rb"
     assert_no_file "test/dummy"
     assert_file "test/test_helper.rb" do |content|
-      assert_match(/require.+spec\/fake\/config\/environment/, content)
+      assert_match(/require_relative.+spec\/fake\/config\/environment/, content)
       assert_match(/ActiveRecord::Migrator\.migrations_paths.+spec\/fake\/db\/migrate/, content)
     end
   end
 
   def test_creating_dummy_without_tests_but_with_dummy_path
     run_generator [destination_root, "--dummy_path", "spec/dummy", "--skip-test"]
-    assert_file "spec/dummy"
-    assert_file "spec/dummy/config/application.rb"
-    assert_no_file "test"
-    assert_no_file "test/test_helper.rb"
-    assert_file '.gitignore' do |contents|
+    assert_directory "spec/dummy"
+    assert_file "spec/dummy/config/application.rb", /#\s+require\s+["']rails\/test_unit\/railtie["']/
+    assert_no_directory "test"
+    assert_file ".gitignore" do |contents|
       assert_match(/spec\/dummy/, contents)
     end
   end
@@ -447,8 +455,8 @@ class PluginGeneratorTest < Rails::Generators::TestCase
   def test_dummy_appplication_skip_listen_by_default
     run_generator
 
-    assert_file 'test/dummy/config/environments/development.rb' do |contents|
-      assert_match(/^\s*# config.file_watcher = ActiveSupport::EventedFileUpdateChecker/, contents)
+    assert_file "test/dummy/config/environments/development.rb" do |contents|
+      assert_match(/^\s*# config\.file_watcher = ActiveSupport::EventedFileUpdateChecker/, contents)
     end
   end
 
@@ -462,22 +470,22 @@ class PluginGeneratorTest < Rails::Generators::TestCase
 
   def test_unnecessary_files_are_not_generated_in_dummy_application
     run_generator
-    assert_no_file 'test/dummy/.gitignore'
-    assert_no_file 'test/dummy/db/seeds.rb'
-    assert_no_file 'test/dummy/Gemfile'
-    assert_no_file 'test/dummy/public/robots.txt'
-    assert_no_file 'test/dummy/README.md'
-    assert_no_directory 'test/dummy/lib/tasks'
-    assert_no_directory 'test/dummy/doc'
-    assert_no_directory 'test/dummy/test'
-    assert_no_directory 'test/dummy/vendor'
+    assert_no_file "test/dummy/.gitignore"
+    assert_no_file "test/dummy/db/seeds.rb"
+    assert_no_file "test/dummy/Gemfile"
+    assert_no_file "test/dummy/public/robots.txt"
+    assert_no_file "test/dummy/README.md"
+    assert_no_directory "test/dummy/lib/tasks"
+    assert_no_directory "test/dummy/test"
+    assert_no_directory "test/dummy/vendor"
+    assert_no_directory "test/dummy/.git"
   end
 
   def test_skipping_test_files
     run_generator [destination_root, "--skip-test"]
-    assert_no_file "test"
-    assert_file '.gitignore' do |contents|
-      assert_no_match(/test\dummy/, contents)
+    assert_no_directory "test"
+    assert_file ".gitignore" do |contents|
+      assert_no_match(/test\/dummy/, contents)
     end
   end
 
@@ -485,10 +493,9 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     run_generator [destination_root, "--skip-gemspec"]
     assert_no_file "bukkits.gemspec"
     assert_file "Gemfile" do |contents|
-      assert_no_match('gemspec', contents)
+      assert_no_match("gemspec", contents)
       assert_match(/gem 'rails'/, contents)
       assert_match_sqlite3(contents)
-      assert_no_match(/# gem "jquery-rails"/, contents)
     end
   end
 
@@ -496,7 +503,7 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     run_generator [destination_root, "--skip-gemspec", "--full"]
     assert_no_file "bukkits.gemspec"
     assert_file "Gemfile" do |contents|
-      assert_no_match('gemspec', contents)
+      assert_no_match("gemspec", contents)
       assert_match(/gem 'rails'/, contents)
       assert_match_sqlite3(contents)
     end
@@ -505,21 +512,36 @@ class PluginGeneratorTest < Rails::Generators::TestCase
   def test_creating_plugin_in_app_directory_adds_gemfile_entry
     # simulate application existence
     gemfile_path = "#{Rails.root}/Gemfile"
-    Object.const_set('APP_PATH', Rails.root)
+    Object.const_set("APP_PATH", Rails.root)
     FileUtils.touch gemfile_path
 
     run_generator
 
     assert_file gemfile_path, /gem 'bukkits', path: 'tmp\/bukkits'/
   ensure
-    Object.send(:remove_const, 'APP_PATH')
+    Object.send(:remove_const, "APP_PATH")
+    FileUtils.rm gemfile_path
+  end
+
+  def test_creating_plugin_only_specify_plugin_name_in_app_directory_adds_gemfile_entry
+    # simulate application existence
+    gemfile_path = "#{Rails.root}/Gemfile"
+    Object.const_set("APP_PATH", Rails.root)
+    FileUtils.touch gemfile_path
+
+    FileUtils.cd(destination_root)
+    run_generator ["bukkits"]
+
+    assert_file gemfile_path, /gem 'bukkits', path: 'bukkits'/
+  ensure
+    Object.send(:remove_const, "APP_PATH")
     FileUtils.rm gemfile_path
   end
 
   def test_skipping_gemfile_entry
     # simulate application existence
     gemfile_path = "#{Rails.root}/Gemfile"
-    Object.const_set('APP_PATH', Rails.root)
+    Object.const_set("APP_PATH", Rails.root)
     FileUtils.touch gemfile_path
 
     run_generator [destination_root, "--skip-gemfile-entry"]
@@ -528,7 +550,7 @@ class PluginGeneratorTest < Rails::Generators::TestCase
       assert_no_match(/gem 'bukkits', path: 'tmp\/bukkits'/, contents)
     end
   ensure
-    Object.send(:remove_const, 'APP_PATH')
+    Object.send(:remove_const, "APP_PATH")
     FileUtils.rm gemfile_path
   end
 
@@ -569,7 +591,7 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     name = "TODO: Write your name"
     email = "TODO: Write your email address"
 
-    run_generator [destination_root, '--skip-git']
+    run_generator [destination_root, "--skip-git"]
     assert_file "MIT-LICENSE" do |contents|
       assert_match name, contents
     end
@@ -580,8 +602,8 @@ class PluginGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_skipping_useless_folders_generation_for_api_engines
-    ['--full', '--mountable'].each do |option|
-      run_generator [destination_root, option, '--api']
+    ["--full", "--mountable"].each do |option|
+      run_generator [destination_root, option, "--api"]
 
       assert_no_directory "app/assets"
       assert_no_directory "app/helpers"
@@ -592,7 +614,7 @@ class PluginGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_application_controller_parent_for_mountable_api_plugins
-    run_generator [destination_root, '--mountable', '--api']
+    run_generator [destination_root, "--mountable", "--api"]
 
     assert_file "app/controllers/bukkits/application_controller.rb" do |content|
       assert_match "ApplicationController < ActionController::API", content
@@ -600,16 +622,15 @@ class PluginGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_dummy_api_application_for_api_plugins
-    run_generator [destination_root, '--api']
+    run_generator [destination_root, "--api"]
 
     assert_file "test/dummy/config/application.rb" do |content|
       assert_match "config.api_only = true", content
     end
   end
 
-
   def test_api_generators_configuration_for_api_engines
-    run_generator [destination_root, '--full', '--api']
+    run_generator [destination_root, "--full", "--api"]
 
     assert_file "lib/bukkits/engine.rb" do |content|
       assert_match "config.generators.api_only = true", content
@@ -617,7 +638,7 @@ class PluginGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_scaffold_generator_for_mountable_api_plugins
-    run_generator [destination_root, '--mountable', '--api']
+    run_generator [destination_root, "--mountable", "--api"]
 
     capture(:stdout) do
       `#{destination_root}/bin/rails g scaffold article`
@@ -634,7 +655,7 @@ class PluginGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_model_with_existent_application_record_in_mountable_engine
-    run_generator [destination_root, '--mountable']
+    run_generator [destination_root, "--mountable"]
     capture(:stdout) do
       `#{destination_root}/bin/rails g model article`
     end
@@ -642,35 +663,36 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     assert_file "app/models/bukkits/article.rb", /class Article < ApplicationRecord/
   end
 
-  def test_generate_application_record_when_does_not_exist_in_mountable_engine
-    run_generator [destination_root, '--mountable']
-    FileUtils.rm "#{destination_root}/app/models/bukkits/application_record.rb"
+  def test_generate_application_mailer_when_does_not_exist_in_mountable_engine
+    run_generator [destination_root, "--mountable"]
+    FileUtils.rm "#{destination_root}/app/mailers/bukkits/application_mailer.rb"
     capture(:stdout) do
-      `#{destination_root}/bin/rails g model article`
+      `#{destination_root}/bin/rails g mailer User`
     end
 
-    assert_file "#{destination_root}/app/models/bukkits/application_record.rb" do |record|
-      assert_match(/module Bukkits/, record)
-      assert_match(/class ApplicationRecord < ActiveRecord::Base/, record)
-      assert_match(/self.abstract_class = true/, record)
+    assert_file "#{destination_root}/app/mailers/bukkits/application_mailer.rb" do |mailer|
+      assert_match(/module Bukkits/, mailer)
+      assert_match(/class ApplicationMailer < ActionMailer::Base/, mailer)
     end
   end
 
-  def test_generate_application_mailer_when_does_not_exist_in_mountable_engine
-    run_generator [destination_root, '--mountable']
-    FileUtils.rm "#{destination_root}/app/mailers/bukkits/application_mailer.rb"
+  def test_generate_mailer_layouts_when_does_not_exist_in_mountable_engine
+    run_generator [destination_root, "--mountable"]
     capture(:stdout) do
       `#{destination_root}/bin/rails g mailer User`
     end
 
-    assert_file "#{destination_root}/app/mailers/bukkits/application_mailer.rb" do |mailer|
-      assert_match(/module Bukkits/, mailer)
-      assert_match(/class ApplicationMailer < ActionMailer::Base/, mailer)
+    assert_file "#{destination_root}/app/views/layouts/bukkits/mailer.text.erb" do |view|
+      assert_match(/<%= yield %>/, view)
+    end
+
+    assert_file "#{destination_root}/app/views/layouts/bukkits/mailer.html.erb" do |view|
+      assert_match(%r{<body>\n    <%= yield %>\n  </body>}, view)
     end
   end
 
   def test_generate_application_job_when_does_not_exist_in_mountable_engine
-    run_generator [destination_root, '--mountable']
+    run_generator [destination_root, "--mountable"]
     FileUtils.rm "#{destination_root}/app/jobs/bukkits/application_job.rb"
     capture(:stdout) do
       `#{destination_root}/bin/rails g job refresh_counters`
@@ -682,48 +704,53 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     end
   end
 
-  def test_after_bundle_callback
-    path = 'http://example.org/rails_template'
-    template = %{ after_bundle { run 'echo ran after_bundle' } }
-    template.instance_eval "def read; self; end" # Make the string respond to read
+  def test_app_update_generates_bin_file
+    run_generator [destination_root, "--mountable"]
+
+    Object.const_set("ENGINE_ROOT", destination_root)
+    FileUtils.rm("#{destination_root}/bin/rails")
+
+    quietly { Rails::Engine::Updater.run(:create_bin_files) }
 
-    check_open = -> *args do
-      assert_equal [ path, 'Accept' => 'application/x-thor-template' ], args
-      template
+    assert_file "#{destination_root}/bin/rails" do |content|
+      assert_match(%r|APP_PATH = File\.expand_path\('\.\./test/dummy/config/application', __dir__\)|, content)
     end
+  ensure
+    Object.send(:remove_const, "ENGINE_ROOT")
+  end
+
+  private
 
-    sequence = ['install', 'echo ran after_bundle']
-    @sequence_step ||= 0
-    ensure_bundler_first = -> command do
-      assert_equal sequence[@sequence_step], command, "commands should be called in sequence #{sequence}"
-      @sequence_step += 1
+    def action(*args, &block)
+      silence(:stdout) { generator.send(*args, &block) }
     end
 
-    generator([destination_root], template: path).stub(:open, check_open, template) do
-      generator.stub(:bundle_command, ensure_bundler_first) do
-        generator.stub(:run, ensure_bundler_first) do
-          quietly { generator.invoke_all }
-        end
-      end
+    def default_files
+      ::DEFAULT_PLUGIN_FILES
     end
 
-    assert_equal 2, @sequence_step
-  end
+    def assert_match_sqlite3(contents)
+      if defined?(JRUBY_VERSION)
+        assert_match(/group :development do\n  gem 'activerecord-jdbcsqlite3-adapter'\nend/, contents)
+      else
+        assert_match(/group :development do\n  gem 'sqlite3'\nend/, contents)
+      end
+    end
 
-protected
-  def action(*args, &block)
-    silence(:stdout){ generator.send(*args, &block) }
-  end
+    def assert_generates_without_bundler(options = {})
+      generator([destination_root], options)
 
-  def default_files
-    ::DEFAULT_PLUGIN_FILES
-  end
+      command_check = -> command do
+        case command
+        when "install"
+          flunk "install expected to not be called"
+        when "exec spring binstub --all"
+          # Called when running tests with spring, let through unscathed.
+        end
+      end
 
-  def assert_match_sqlite3(contents)
-    if defined?(JRUBY_VERSION)
-      assert_match(/group :development do\n  gem 'activerecord-jdbcsqlite3-adapter'\nend/, contents)
-    else
-      assert_match(/group :development do\n  gem 'sqlite3'\nend/, contents)
+      generator.stub :bundle_command, command_check do
+        quietly { generator.invoke_all }
+      end
     end
-  end
 end
diff --git a/railties/test/generators/plugin_test_helper.rb b/railties/test/generators/plugin_test_helper.rb
index 96c1b1d31f..528f8d88f9 100644
--- a/railties/test/generators/plugin_test_helper.rb
+++ b/railties/test/generators/plugin_test_helper.rb
@@ -1,5 +1,7 @@
-require 'abstract_unit'
-require 'tmpdir'
+# frozen_string_literal: true
+
+require "abstract_unit"
+require "tmpdir"
 
 module PluginTestHelper
   def create_test_file(name, pass: true)
@@ -15,7 +17,7 @@ module PluginTestHelper
     RUBY
   end
 
-  def plugin_file(path, contents, mode: 'w')
+  def plugin_file(path, contents, mode: "w")
     FileUtils.mkdir_p File.dirname("#{plugin_path}/#{path}")
     File.open("#{plugin_path}/#{path}", mode) do |f|
       f.puts contents
diff --git a/railties/test/generators/plugin_test_runner_test.rb b/railties/test/generators/plugin_test_runner_test.rb
index ef6359fece..89c3f1e496 100644
--- a/railties/test/generators/plugin_test_runner_test.rb
+++ b/railties/test/generators/plugin_test_runner_test.rb
@@ -1,12 +1,14 @@
-require 'generators/plugin_test_helper'
+# frozen_string_literal: true
+
+require "generators/plugin_test_helper"
 
 class PluginTestRunnerTest < ActiveSupport::TestCase
   include PluginTestHelper
 
   def setup
-    @destination_root = Dir.mktmpdir('bukkits')
+    @destination_root = Dir.mktmpdir("bukkits")
     Dir.chdir(@destination_root) { `bundle exec rails plugin new bukkits --skip-bundle` }
-    plugin_file 'test/dummy/db/schema.rb', ''
+    plugin_file "test/dummy/db/schema.rb", ""
   end
 
   def teardown
@@ -14,20 +16,20 @@ class PluginTestRunnerTest < ActiveSupport::TestCase
   end
 
   def test_run_single_file
-    create_test_file 'foo'
-    create_test_file 'bar'
+    create_test_file "foo"
+    create_test_file "bar"
     assert_match "1 runs, 1 assertions, 0 failures", run_test_command("test/foo_test.rb")
   end
 
   def test_run_multiple_files
-    create_test_file 'foo'
-    create_test_file 'bar'
+    create_test_file "foo"
+    create_test_file "bar"
     assert_match "2 runs, 2 assertions, 0 failures", run_test_command("test/foo_test.rb test/bar_test.rb")
   end
 
   def test_mix_files_and_line_filters
-    create_test_file 'account'
-    plugin_file 'test/post_test.rb', <<-RUBY
+    create_test_file "account"
+    plugin_file "test/post_test.rb", <<-RUBY
       require 'test_helper'
 
       class PostTest < ActiveSupport::TestCase
@@ -42,50 +44,73 @@ class PluginTestRunnerTest < ActiveSupport::TestCase
       end
     RUBY
 
-    run_test_command('test/account_test.rb test/post_test.rb:4').tap do |output|
-      assert_match 'AccountTest', output
-      assert_match 'PostTest', output
-      assert_match '2 runs, 2 assertions', output
+    run_test_command("test/account_test.rb test/post_test.rb:4").tap do |output|
+      assert_match "AccountTest", output
+      assert_match "PostTest", output
+      assert_match "2 runs, 2 assertions", output
     end
   end
 
   def test_multiple_line_filters
-    create_test_file 'account'
-    create_test_file 'post'
+    create_test_file "account"
+    create_test_file "post"
 
-    run_test_command('test/account_test.rb:4 test/post_test.rb:4').tap do |output|
-      assert_match 'AccountTest', output
-      assert_match 'PostTest', output
+    run_test_command("test/account_test.rb:4 test/post_test.rb:4").tap do |output|
+      assert_match "AccountTest", output
+      assert_match "PostTest", output
     end
   end
 
   def test_output_inline_by_default
-    create_test_file 'post', pass: false
+    create_test_file "post", pass: false
 
-    output = run_test_command('test/post_test.rb')
+    output = run_test_command("test/post_test.rb")
     expect = %r{Running:\n\nPostTest\nF\n\nFailure:\nPostTest#test_truth \[[^\]]+test/post_test.rb:6\]:\nwups!\n\nbin/test (/private)?#{plugin_path}/test/post_test.rb:4}
     assert_match expect, output
   end
 
   def test_only_inline_failure_output
-    create_test_file 'post', pass: false
+    create_test_file "post", pass: false
 
-    output = run_test_command('test/post_test.rb')
-    assert_match %r{Finished in.*\n\n1 runs, 1 assertions}, output
+    output = run_test_command("test/post_test.rb")
+    assert_match %r{Finished in.*\n1 runs, 1 assertions}, output
   end
 
   def test_fail_fast
-    create_test_file 'post', pass: false
+    create_test_file "post", pass: false
 
     assert_match(/Interrupt/,
-      capture(:stderr) { run_test_command('test/post_test.rb --fail-fast') })
+      capture(:stderr) { run_test_command("test/post_test.rb --fail-fast") })
   end
 
   def test_raise_error_when_specified_file_does_not_exist
-    error = capture(:stderr) { run_test_command('test/not_exists.rb') }
+    error = capture(:stderr) { run_test_command("test/not_exists.rb") }
     assert_match(%r{cannot load such file.+test/not_exists\.rb}, error)
   end
 
+  def test_executed_only_once
+    create_test_file "foo"
+    result = run_test_command("test/foo_test.rb")
+    assert_equal 1, result.scan(/1 runs, 1 assertions, 0 failures/).length
+  end
+
+  def test_warnings_option
+    plugin_file "test/models/warnings_test.rb", <<-RUBY
+      require 'test_helper'
+      def test_warnings
+        a = 1
+      end
+    RUBY
+    assert_match(/warning: assigned but unused variable/,
+      capture(:stderr) { run_test_command("test/models/warnings_test.rb -w") })
+  end
+
+  def test_run_rake_test
+    create_test_file "foo"
+    result = Dir.chdir(plugin_path) { `rake test TEST=test/foo_test.rb` }
+    assert_match "1 runs, 1 assertions, 0 failures", result
+  end
+
   private
     def plugin_path
       "#{@destination_root}/bukkits"
diff --git a/railties/test/generators/resource_generator_test.rb b/railties/test/generators/resource_generator_test.rb
index addaf83bc8..63a2cd3869 100644
--- a/railties/test/generators/resource_generator_test.rb
+++ b/railties/test/generators/resource_generator_test.rb
@@ -1,5 +1,7 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/rails/resource/resource_generator'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/resource/resource_generator"
 
 class ResourceGeneratorTest < Rails::Generators::TestCase
   include GeneratorsTestHelper
@@ -60,14 +62,14 @@ class ResourceGeneratorTest < Rails::Generators::TestCase
 
   def test_plural_names_are_singularized
     content = run_generator ["accounts".freeze]
-    assert_file "app/models/account.rb", /class Account < ActiveRecord::Base/
+    assert_file "app/models/account.rb", /class Account < ApplicationRecord/
     assert_file "test/models/account_test.rb", /class AccountTest/
     assert_match(/\[WARNING\] The model name 'accounts' was recognized as a plural, using the singular 'account' instead\. Override with --force-plural or setup custom inflection rules for this noun before running the generator\./, content)
   end
 
   def test_plural_names_can_be_forced
     content = run_generator ["accounts", "--force-plural"]
-    assert_file "app/models/accounts.rb", /class Accounts < ActiveRecord::Base/
+    assert_file "app/models/accounts.rb", /class Accounts < ApplicationRecord/
     assert_file "test/models/accounts_test.rb", /class AccountsTest/
     assert_no_match(/\[WARNING\]/, content)
   end
diff --git a/railties/test/generators/scaffold_controller_generator_test.rb b/railties/test/generators/scaffold_controller_generator_test.rb
index c37e289f4b..513b037043 100644
--- a/railties/test/generators/scaffold_controller_generator_test.rb
+++ b/railties/test/generators/scaffold_controller_generator_test.rb
@@ -1,5 +1,7 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/rails/scaffold_controller/scaffold_controller_generator'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/scaffold_controller/scaffold_controller_generator"
 
 module Unknown
   module Generators
@@ -172,6 +174,29 @@ class ScaffoldControllerGeneratorTest < Rails::Generators::TestCase
       assert_instance_method :index, content do |m|
         assert_match("@users = User.all", m)
       end
+
+      assert_instance_method :create, content do |m|
+        assert_match("redirect_to [:admin, @user]", m)
+      end
+
+      assert_instance_method :update, content do |m|
+        assert_match("redirect_to [:admin, @user]", m)
+      end
+    end
+
+    assert_file "app/views/admin/users/index.html.erb" do |content|
+      assert_match("'Show', [:admin, user]", content)
+      assert_match("'Edit', edit_admin_user_path(user)", content)
+      assert_match("'Destroy', [:admin, user]", content)
+      assert_match("'New User', new_admin_user_path", content)
+    end
+
+    assert_file "app/views/admin/users/new.html.erb" do |content|
+      assert_match("'Back', admin_users_path", content)
+    end
+
+    assert_file "app/views/admin/users/_form.html.erb" do |content|
+      assert_match("model: [:admin, user]", content)
     end
   end
 
@@ -230,6 +255,12 @@ class ScaffoldControllerGeneratorTest < Rails::Generators::TestCase
         assert_match(/@user\.destroy/, m)
       end
     end
+
+    assert_no_file "app/views/users/index.html.erb"
+    assert_no_file "app/views/users/edit.html.erb"
+    assert_no_file "app/views/users/show.html.erb"
+    assert_no_file "app/views/users/new.html.erb"
+    assert_no_file "app/views/users/_form.html.erb"
   end
 
   def test_api_controller_tests
@@ -238,8 +269,8 @@ class ScaffoldControllerGeneratorTest < Rails::Generators::TestCase
     assert_file "test/controllers/users_controller_test.rb" do |content|
       assert_match(/class UsersControllerTest < ActionDispatch::IntegrationTest/, content)
       assert_match(/test "should get index"/, content)
-      assert_match(/post users_url, params: \{ user: \{ age: @user\.age, name: @user\.name, organization_id: @user\.organization_id, organization_type: @user\.organization_type \} \}/, content)
-      assert_match(/patch user_url\(@user\), params: \{ user: \{ age: @user\.age, name: @user\.name, organization_id: @user\.organization_id, organization_type: @user\.organization_type \} \}/, content)
+      assert_match(/post users_url, params: \{ user: \{ age: @user\.age, name: @user\.name, organization_id: @user\.organization_id, organization_type: @user\.organization_type \} \}, as: :json/, content)
+      assert_match(/patch user_url\(@user\), params: \{ user: \{ age: @user\.age, name: @user\.name, organization_id: @user\.organization_id, organization_type: @user\.organization_type \} \}, as: :json/, content)
       assert_no_match(/assert_redirected_to/, content)
     end
   end
diff --git a/railties/test/generators/scaffold_generator_test.rb b/railties/test/generators/scaffold_generator_test.rb
index 5e45120704..b6294c3b94 100644
--- a/railties/test/generators/scaffold_generator_test.rb
+++ b/railties/test/generators/scaffold_generator_test.rb
@@ -1,5 +1,7 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/rails/scaffold/scaffold_generator'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/scaffold/scaffold_generator"
 
 class ScaffoldGeneratorTest < Rails::Generators::TestCase
   include GeneratorsTestHelper
@@ -11,7 +13,7 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
     run_generator
 
     # Model
-    assert_file "app/models/product_line.rb", /class ProductLine < ActiveRecord::Base/
+    assert_file "app/models/product_line.rb", /class ProductLine < ApplicationRecord/
     assert_file "test/models/product_line_test.rb", /class ProductLineTest < ActiveSupport::TestCase/
     assert_file "test/fixtures/product_lines.yml"
     assert_migration "db/migrate/create_product_lines.rb", /belongs_to :product/
@@ -62,6 +64,14 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
       assert_match(/patch product_line_url\(@product_line\), params: \{ product_line: \{ product_id: @product_line\.product_id, title: @product_line\.title, user_id: @product_line\.user_id \} \}/, test)
     end
 
+    # System tests
+    assert_file "test/system/product_lines_test.rb" do |test|
+      assert_match(/class ProductLinesTest < ApplicationSystemTestCase/, test)
+      assert_match(/visit product_lines_url/, test)
+      assert_match(/fill_in "Title", with: @product_line\.title/, test)
+      assert_match(/assert_text "Product line was successfully updated"/, test)
+    end
+
     # Views
     assert_no_file "app/views/layouts/product_lines.html.erb"
 
@@ -74,8 +84,8 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
     end
 
     assert_file "app/views/product_lines/_form.html.erb" do |test|
-      assert_match 'product_line', test
-      assert_no_match '@product_line', test
+      assert_match "product_line", test
+      assert_no_match "@product_line", test
     end
 
     # Helpers
@@ -91,7 +101,7 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
     run_generator %w(product_line title:string product:belongs_to user:references --api --no-template-engine --no-helper --no-assets)
 
     # Model
-    assert_file "app/models/product_line.rb", /class ProductLine < ActiveRecord::Base/
+    assert_file "app/models/product_line.rb", /class ProductLine < ApplicationRecord/
     assert_file "test/models/product_line_test.rb", /class ProductLineTest < ActiveSupport::TestCase/
     assert_file "test/fixtures/product_lines.yml"
     assert_migration "db/migrate/create_product_lines.rb", /belongs_to :product/
@@ -141,6 +151,9 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
       assert_no_match(/assert_redirected_to/, test)
     end
 
+    # System tests
+    assert_no_file "test/system/product_lines_test.rb"
+
     # Views
     assert_no_file "app/views/layouts/product_lines.html.erb"
 
@@ -168,6 +181,16 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
     end
   end
 
+  def test_system_tests_without_attributes
+    run_generator ["product_line"]
+
+    assert_file "test/system/product_lines_test.rb" do |content|
+      assert_match(/class ProductLinesTest < ApplicationSystemTestCase/, content)
+      assert_match(/test "visiting the index"/, content)
+      assert_no_match(/fill_in/, content)
+    end
+  end
+
   def test_scaffold_on_revoke
     run_generator
     run_generator ["product_line"], behavior: :revoke
@@ -187,6 +210,9 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
     assert_no_file "app/controllers/product_lines_controller.rb"
     assert_no_file "test/controllers/product_lines_controller_test.rb"
 
+    # System tests
+    assert_no_file "test/system/product_lines_test.rb"
+
     # Views
     assert_no_file "app/views/product_lines"
     assert_no_file "app/views/layouts/product_lines.html.erb"
@@ -205,7 +231,7 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
 
     # Model
     assert_file "app/models/admin.rb", /module Admin/
-    assert_file "app/models/admin/role.rb", /class Admin::Role < ActiveRecord::Base/
+    assert_file "app/models/admin/role.rb", /class Admin::Role < ApplicationRecord/
     assert_file "test/models/admin/role_test.rb", /class Admin::RoleTest < ActiveSupport::TestCase/
     assert_file "test/fixtures/admin/roles.yml"
     assert_migration "db/migrate/create_admin_roles.rb"
@@ -252,8 +278,18 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
     assert_file "test/controllers/admin/roles_controller_test.rb",
                 /class Admin::RolesControllerTest < ActionDispatch::IntegrationTest/
 
+    assert_file "test/system/admin/roles_test.rb",
+                /class Admin::RolesTest < ApplicationSystemTestCase/
+
     # Views
-    %w(index edit new show _form).each do |view|
+    assert_file "app/views/admin/roles/index.html.erb" do |content|
+      assert_match("'Show', admin_role", content)
+      assert_match("'Edit', edit_admin_role_path(admin_role)", content)
+      assert_match("'Destroy', admin_role", content)
+      assert_match("'New Admin Role', new_admin_role_path", content)
+    end
+
+    %w(edit new show _form).each do |view|
       assert_file "app/views/admin/roles/#{view}.html.erb"
     end
     assert_no_file "app/views/layouts/admin/roles.html.erb"
@@ -269,7 +305,7 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
 
   def test_scaffold_with_namespace_on_revoke
     run_generator [ "admin/role", "name:string", "description:string" ]
-    run_generator [ "admin/role" ], :behavior => :revoke
+    run_generator [ "admin/role" ], behavior: :revoke
 
     # Model
     assert_file "app/models/admin.rb" # ( should not be remove )
@@ -287,6 +323,9 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
     assert_no_file "app/controllers/admin/roles_controller.rb"
     assert_no_file "test/controllers/admin/roles_controller_test.rb"
 
+    # System tests
+    assert_no_file "test/system/admin/roles_test.rb"
+
     # Views
     assert_no_file "app/views/admin/roles"
     assert_no_file "app/views/layouts/admin/roles.html.erb"
@@ -310,7 +349,7 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
     end
     File.open(route_path, "wb") { |file| file.write(content) }
 
-    run_generator ["product_line"], :behavior => :revoke
+    run_generator ["product_line"], behavior: :revoke
 
     assert_file "config/routes.rb", /\.routes\.draw do\s*\|map\|\s*$/
   end
@@ -322,13 +361,13 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
     content = File.read(route_path)
 
     # Remove all of the comments and blank lines from the routes file
-    content.gsub!(/^  \#.*\n/, '')
-    content.gsub!(/^\n/, '')
+    content.gsub!(/^  \#.*\n/, "")
+    content.gsub!(/^\n/, "")
 
     File.open(route_path, "wb") { |file| file.write(content) }
     assert_file "config/routes.rb", /\.routes\.draw do\n  resources :product_lines\nend\n\z/
 
-    run_generator ["product_line"], :behavior => :revoke
+    run_generator ["product_line"], behavior: :revoke
 
     assert_file "config/routes.rb", /\.routes\.draw do\nend\n\z/
   end
@@ -432,8 +471,8 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
     end
 
     assert_file "app/views/accounts/_form.html.erb" do |content|
-      assert_match(/^\W{4}<%= f\.text_field :name %>/, content)
-      assert_match(/^\W{4}<%= f\.text_field :currency_id %>/, content)
+      assert_match(/^\W{4}<%= form\.text_field :name, id: :account_name %>/, content)
+      assert_match(/^\W{4}<%= form\.text_field :currency_id, id: :account_currency_id %>/, content)
     end
   end
 
@@ -456,8 +495,8 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
     end
 
     assert_file "app/views/users/_form.html.erb" do |content|
-      assert_match(/<%= f\.password_field :password %>/, content)
-      assert_match(/<%= f\.password_field :password_confirmation %>/, content)
+      assert_match(/<%= form\.password_field :password, id: :user_password %>/, content)
+      assert_match(/<%= form\.password_field :password_confirmation, id: :user_password_confirmation %>/, content)
     end
 
     assert_file "app/views/users/index.html.erb" do |content|
@@ -473,6 +512,11 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
       assert_match(/password_confirmation: 'secret'/, content)
     end
 
+    assert_file "test/system/users_test.rb" do |content|
+      assert_match(/fill_in "Password", with: 'secret'/, content)
+      assert_match(/fill_in "Password Confirmation", with: 'secret'/, content)
+    end
+
     assert_file "test/fixtures/users.yml" do |content|
       assert_match(/password_digest: <%= BCrypt::Password.create\('secret'\) %>/, content)
     end
@@ -488,7 +532,27 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
         `bin/rails g scaffold User name:string age:integer;
         bin/rails db:migrate`
       end
-      assert_match(/8 runs, 13 assertions, 0 failures, 0 errors/, `bin/rails test 2>&1`)
+      assert_match(/8 runs, 10 assertions, 0 failures, 0 errors/, `bin/rails test 2>&1`)
+    end
+  end
+
+  def test_scaffold_tests_pass_by_default_inside_namespaced_mountable_engine
+    Dir.chdir(destination_root) { `bundle exec rails plugin new bukkits-admin --mountable` }
+
+    engine_path = File.join(destination_root, "bukkits-admin")
+
+    Dir.chdir(engine_path) do
+      quietly do
+        `bin/rails g scaffold User name:string age:integer;
+        bin/rails db:migrate`
+      end
+
+      assert_file "bukkits-admin/app/controllers/bukkits/admin/users_controller.rb" do |content|
+        assert_match(/module Bukkits::Admin/, content)
+        assert_match(/class UsersController < ApplicationController/, content)
+      end
+
+      assert_match(/8 runs, 10 assertions, 0 failures, 0 errors/, `bin/rails test 2>&1`)
     end
   end
 
@@ -502,7 +566,7 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
         `bin/rails g scaffold User name:string age:integer;
         bin/rails db:migrate`
       end
-      assert_match(/8 runs, 13 assertions, 0 failures, 0 errors/, `bin/rails test 2>&1`)
+      assert_match(/8 runs, 10 assertions, 0 failures, 0 errors/, `bin/rails test 2>&1`)
     end
   end
 
@@ -533,4 +597,63 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
       assert_match(/6 runs, 8 assertions, 0 failures, 0 errors/, `bin/rails test 2>&1`)
     end
   end
+
+  def test_scaffold_on_invoke_inside_mountable_engine
+    Dir.chdir(destination_root) { `bundle exec rails plugin new bukkits --mountable` }
+    engine_path = File.join(destination_root, "bukkits")
+
+    Dir.chdir(engine_path) do
+      quietly { `bin/rails generate scaffold User name:string age:integer` }
+
+      assert File.exist?("app/models/bukkits/user.rb")
+      assert File.exist?("test/models/bukkits/user_test.rb")
+      assert File.exist?("test/fixtures/bukkits/users.yml")
+
+      assert File.exist?("app/controllers/bukkits/users_controller.rb")
+      assert File.exist?("test/controllers/bukkits/users_controller_test.rb")
+
+      assert File.exist?("test/system/bukkits/users_test.rb")
+
+      assert File.exist?("app/views/bukkits/users/index.html.erb")
+      assert File.exist?("app/views/bukkits/users/edit.html.erb")
+      assert File.exist?("app/views/bukkits/users/show.html.erb")
+      assert File.exist?("app/views/bukkits/users/new.html.erb")
+      assert File.exist?("app/views/bukkits/users/_form.html.erb")
+
+      assert File.exist?("app/helpers/bukkits/users_helper.rb")
+
+      assert File.exist?("app/assets/javascripts/bukkits/users.js")
+      assert File.exist?("app/assets/stylesheets/bukkits/users.css")
+    end
+  end
+
+  def test_scaffold_on_revoke_inside_mountable_engine
+    Dir.chdir(destination_root) { `bundle exec rails plugin new bukkits --mountable` }
+    engine_path = File.join(destination_root, "bukkits")
+
+    Dir.chdir(engine_path) do
+      quietly { `bin/rails generate scaffold User name:string age:integer` }
+      quietly { `bin/rails destroy scaffold User` }
+
+      assert_not File.exist?("app/models/bukkits/user.rb")
+      assert_not File.exist?("test/models/bukkits/user_test.rb")
+      assert_not File.exist?("test/fixtures/bukkits/users.yml")
+
+      assert_not File.exist?("app/controllers/bukkits/users_controller.rb")
+      assert_not File.exist?("test/controllers/bukkits/users_controller_test.rb")
+
+      assert_not File.exist?("test/system/bukkits/users_test.rb")
+
+      assert_not File.exist?("app/views/bukkits/users/index.html.erb")
+      assert_not File.exist?("app/views/bukkits/users/edit.html.erb")
+      assert_not File.exist?("app/views/bukkits/users/show.html.erb")
+      assert_not File.exist?("app/views/bukkits/users/new.html.erb")
+      assert_not File.exist?("app/views/bukkits/users/_form.html.erb")
+
+      assert_not File.exist?("app/helpers/bukkits/users_helper.rb")
+
+      assert_not File.exist?("app/assets/javascripts/bukkits/users.js")
+      assert_not File.exist?("app/assets/stylesheets/bukkits/users.css")
+    end
+  end
 end
diff --git a/railties/test/generators/shared_generator_tests.rb b/railties/test/generators/shared_generator_tests.rb
index e83d54890a..654d16de65 100644
--- a/railties/test/generators/shared_generator_tests.rb
+++ b/railties/test/generators/shared_generator_tests.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 #
 # Tests, setup, and teardown common to the application and plugin generator suites.
 #
@@ -5,7 +7,7 @@ module SharedGeneratorTests
   def setup
     Rails.application = TestApp::Application
     super
-    Rails::Generators::AppGenerator.instance_variable_set('@desc', nil)
+    Rails::Generators::AppGenerator.instance_variable_set("@desc", nil)
 
     Kernel::silence_warnings do
       Thor::Base.shell.send(:attr_accessor, :always_force)
@@ -16,47 +18,27 @@ module SharedGeneratorTests
 
   def teardown
     super
-    Rails::Generators::AppGenerator.instance_variable_set('@desc', nil)
+    Rails::Generators::AppGenerator.instance_variable_set("@desc", nil)
     Rails.application = TestApp::Application.instance
   end
 
+  def application_path
+    destination_root
+  end
+
   def test_skeleton_is_created
     run_generator
 
     default_files.each { |path| assert_file path }
   end
 
-  def assert_generates_with_bundler(options = {})
-    generator([destination_root], options)
-
-    command_check = -> command do
-      @install_called ||= 0
-
-      case command
-      when 'install'
-        @install_called += 1
-        assert_equal 1, @install_called, "install expected to be called once, but was called #{@install_called} times"
-      when 'exec spring binstub --all'
-        # Called when running tests with spring, let through unscathed.
-      end
-    end
-
-    generator.stub :bundle_command, command_check do
-      quietly { generator.invoke_all }
-    end
-  end
-
-  def test_generation_runs_bundle_install
-    assert_generates_with_bundler
-  end
-
   def test_plugin_new_generate_pretend
     run_generator ["testapp", "--pretend"]
-    default_files.each{ |path| assert_no_file File.join("testapp",path) }
+    default_files.each { |path| assert_no_file File.join("testapp", path) }
   end
 
   def test_invalid_database_option_raises_an_error
-    content = capture(:stderr){ run_generator([destination_root, "-d", "unknown"]) }
+    content = capture(:stderr) { run_generator([destination_root, "-d", "unknown"]) }
     assert_match(/Invalid value for \-\-database option/, content)
   end
 
@@ -68,15 +50,15 @@ module SharedGeneratorTests
   def test_name_collision_raises_an_error
     reserved_words = %w[application destroy plugin runner test]
     reserved_words.each do |reserved|
-      content = capture(:stderr){ run_generator [File.join(destination_root, reserved)] }
-      assert_match(/Invalid \w+ name #{reserved}. Please give a name which does not match one of the reserved rails words: application, destroy, plugin, runner, test\n/, content)
+      content = capture(:stderr) { run_generator [File.join(destination_root, reserved)] }
+      assert_match(/Invalid \w+ name #{reserved}\. Please give a name which does not match one of the reserved rails words: application, destroy, plugin, runner, test\n/, content)
     end
   end
 
   def test_name_raises_an_error_if_name_already_used_constant
     %w{ String Hash Class Module Set Symbol }.each do |ruby_class|
-      content = capture(:stderr){ run_generator [File.join(destination_root, ruby_class)] }
-      assert_match(/Invalid \w+ name #{ruby_class}, constant #{ruby_class} is already in use. Please choose another \w+ name.\n/, content)
+      content = capture(:stderr) { run_generator [File.join(destination_root, ruby_class)] }
+      assert_match(/Invalid \w+ name #{ruby_class}, constant #{ruby_class} is already in use\. Please choose another \w+ name\.\n/, content)
     end
   end
 
@@ -92,7 +74,7 @@ module SharedGeneratorTests
 
   def test_template_raises_an_error_with_invalid_path
     quietly do
-      content = capture(:stderr){ run_generator([destination_root, "-m", "non/existent/path"]) }
+      content = capture(:stderr) { run_generator([destination_root, "-m", "non/existent/path"]) }
 
       assert_match(/The template \[.*\] could not be loaded/, content)
       assert_match(/non\/existent\/path/, content)
@@ -101,11 +83,11 @@ module SharedGeneratorTests
 
   def test_template_is_executed_when_supplied_an_https_path
     path = "https://gist.github.com/josevalim/103208/raw/"
-    template = %{ say "It works!" }
+    template = %{ say "It works!" }.dup
     template.instance_eval "def read; self; end" # Make the string respond to read
 
     check_open = -> *args do
-      assert_equal [ path, 'Accept' => 'application/x-thor-template' ], args
+      assert_equal [ path, "Accept" => "application/x-thor-template" ], args
       template
     end
 
@@ -114,21 +96,10 @@ module SharedGeneratorTests
     end
   end
 
-  def test_dev_option
-    assert_generates_with_bundler dev: true
-    rails_path = File.expand_path('../../..', Rails.root)
-    assert_file 'Gemfile', /^gem\s+["']rails["'],\s+path:\s+["']#{Regexp.escape(rails_path)}["']$/
-  end
-
-  def test_edge_option
-    assert_generates_with_bundler edge: true
-    assert_file 'Gemfile', %r{^gem\s+["']rails["'],\s+github:\s+["']#{Regexp.escape("rails/rails")}["']$}
-  end
-
   def test_skip_gemfile
     assert_not_called(generator([destination_root], skip_gemfile: true), :bundle_command) do
       quietly { generator.invoke_all }
-      assert_no_file 'Gemfile'
+      assert_no_file "Gemfile"
     end
   end
 
@@ -137,22 +108,163 @@ module SharedGeneratorTests
       quietly { generator.invoke_all }
       # skip_bundle is only about running bundle install, ensure the Gemfile is still
       # generated.
-      assert_file 'Gemfile'
+      assert_file "Gemfile"
     end
   end
 
   def test_skip_git
-    run_generator [destination_root, '--skip-git', '--full']
-    assert_no_file('.gitignore')
+    run_generator [destination_root, "--skip-git", "--full"]
+    assert_no_file(".gitignore")
+    assert_no_directory(".git")
   end
 
   def test_skip_keeps
-    run_generator [destination_root, '--skip-keeps', '--full']
+    run_generator [destination_root, "--skip-keeps", "--full"]
 
-    assert_file '.gitignore' do |content|
+    assert_file ".gitignore" do |content|
       assert_no_match(/\.keep/, content)
     end
 
-    assert_no_file('app/models/concerns/.keep')
+    assert_no_file("app/models/concerns/.keep")
+  end
+
+  def test_default_frameworks_are_required_when_others_are_removed
+    run_generator [destination_root, "--skip-active-record", "--skip-action-mailer", "--skip-action-cable", "--skip-sprockets"]
+    assert_file "#{application_path}/config/application.rb", /require\s+["']rails["']/
+    assert_file "#{application_path}/config/application.rb", /require\s+["']active_model\/railtie["']/
+    assert_file "#{application_path}/config/application.rb", /require\s+["']active_job\/railtie["']/
+    assert_file "#{application_path}/config/application.rb", /require\s+["']action_controller\/railtie["']/
+    assert_file "#{application_path}/config/application.rb", /require\s+["']action_view\/railtie["']/
+    assert_file "#{application_path}/config/application.rb", /require\s+["']active_storage\/engine["']/
+  end
+
+  def test_generator_without_skips
+    run_generator
+    assert_file "#{application_path}/config/application.rb", /\s+require\s+["']rails\/all["']/
+    assert_file "#{application_path}/config/environments/development.rb" do |content|
+      assert_match(/config\.action_mailer\.raise_delivery_errors = false/, content)
+    end
+    assert_file "#{application_path}/config/environments/test.rb" do |content|
+      assert_match(/config\.action_mailer\.delivery_method = :test/, content)
+    end
+    assert_file "#{application_path}/config/environments/production.rb" do |content|
+      assert_match(/# config\.action_mailer\.raise_delivery_errors = false/, content)
+      assert_match(/^  # config\.require_master_key = true/, content)
+    end
+  end
+
+  def test_gitignore_when_sqlite3
+    run_generator
+
+    assert_file ".gitignore" do |content|
+      assert_match(/sqlite3/, content)
+    end
+  end
+
+  def test_gitignore_when_non_sqlite3_db
+    run_generator([destination_root, "-d", "mysql"])
+
+    assert_file ".gitignore" do |content|
+      assert_no_match(/sqlite/i, content)
+    end
+  end
+
+  def test_generator_if_skip_active_record_is_given
+    run_generator [destination_root, "--skip-active-record"]
+    assert_no_directory "#{application_path}/db/"
+    assert_no_file "#{application_path}/config/database.yml"
+    assert_no_file "#{application_path}/app/models/application_record.rb"
+    assert_file "#{application_path}/config/application.rb", /#\s+require\s+["']active_record\/railtie["']/
+    assert_file "test/test_helper.rb" do |helper_content|
+      assert_no_match(/fixtures :all/, helper_content)
+    end
+    assert_file "#{application_path}/bin/setup" do |setup_content|
+      assert_no_match(/db:setup/, setup_content)
+    end
+    assert_file "#{application_path}/bin/update" do |update_content|
+      assert_no_match(/db:migrate/, update_content)
+    end
+    assert_file ".gitignore" do |content|
+      assert_no_match(/sqlite/i, content)
+    end
+  end
+
+  def test_generator_if_skip_action_mailer_is_given
+    run_generator [destination_root, "--skip-action-mailer"]
+    assert_file "#{application_path}/config/application.rb", /#\s+require\s+["']action_mailer\/railtie["']/
+    assert_file "#{application_path}/config/environments/development.rb" do |content|
+      assert_no_match(/config\.action_mailer/, content)
+    end
+    assert_file "#{application_path}/config/environments/test.rb" do |content|
+      assert_no_match(/config\.action_mailer/, content)
+    end
+    assert_file "#{application_path}/config/environments/production.rb" do |content|
+      assert_no_match(/config\.action_mailer/, content)
+    end
+    assert_no_directory "#{application_path}/app/mailers"
+    assert_no_directory "#{application_path}/test/mailers"
+  end
+
+  def test_generator_if_skip_action_cable_is_given
+    run_generator [destination_root, "--skip-action-cable"]
+    assert_file "#{application_path}/config/application.rb", /#\s+require\s+["']action_cable\/engine["']/
+    assert_no_file "#{application_path}/config/cable.yml"
+    assert_no_file "#{application_path}/app/assets/javascripts/cable.js"
+    assert_no_directory "#{application_path}/app/assets/javascripts/channels"
+    assert_no_directory "#{application_path}/app/channels"
+    assert_file "Gemfile" do |content|
+      assert_no_match(/redis/, content)
+    end
+  end
+
+  def test_generator_if_skip_sprockets_is_given
+    run_generator [destination_root, "--skip-sprockets"]
+
+    assert_no_file "#{application_path}/config/initializers/assets.rb"
+
+    assert_file "#{application_path}/config/application.rb", /#\s+require\s+["']sprockets\/railtie["']/
+
+    assert_file "Gemfile" do |content|
+      assert_no_match(/sass-rails/, content)
+      assert_no_match(/uglifier/, content)
+      assert_no_match(/coffee-rails/, content)
+    end
+
+    assert_file "#{application_path}/config/environments/development.rb" do |content|
+      assert_no_match(/config\.assets\.debug/, content)
+    end
+
+    assert_file "#{application_path}/config/environments/production.rb" do |content|
+      assert_no_match(/config\.assets\.digest/, content)
+      assert_no_match(/config\.assets\.js_compressor/, content)
+      assert_no_match(/config\.assets\.css_compressor/, content)
+      assert_no_match(/config\.assets\.compile/, content)
+    end
+  end
+
+  def test_generator_for_yarn
+    run_generator
+    assert_file "#{application_path}/package.json", /dependencies/
+    assert_file "#{application_path}/config/initializers/assets.rb", /node_modules/
+
+    assert_file ".gitignore" do |content|
+      assert_match(/node_modules/, content)
+      assert_match(/yarn-error\.log/, content)
+    end
+  end
+
+  def test_generator_for_yarn_skipped
+    run_generator([destination_root, "--skip-yarn"])
+    assert_no_file "#{application_path}/package.json"
+    assert_no_file "#{application_path}/bin/yarn"
+
+    assert_file "#{application_path}/config/initializers/assets.rb" do |content|
+      assert_no_match(/node_modules/, content)
+    end
+
+    assert_file ".gitignore" do |content|
+      assert_no_match(/node_modules/, content)
+      assert_no_match(/yarn-error\.log/, content)
+    end
   end
 end
diff --git a/railties/test/generators/system_test_generator_test.rb b/railties/test/generators/system_test_generator_test.rb
new file mode 100644
index 0000000000..efa70a050b
--- /dev/null
+++ b/railties/test/generators/system_test_generator_test.rb
@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/system_test/system_test_generator"
+
+class SystemTestGeneratorTest < Rails::Generators::TestCase
+  include GeneratorsTestHelper
+  arguments %w(user)
+
+  def test_system_test_skeleton_is_created
+    run_generator
+    assert_file "test/system/users_test.rb", /class UsersTest < ApplicationSystemTestCase/
+  end
+
+  def test_namespaced_system_test_skeleton_is_created
+    run_generator %w(admin/user)
+    assert_file "test/system/admin/users_test.rb", /class Admin::UsersTest < ApplicationSystemTestCase/
+  end
+end
diff --git a/railties/test/generators/task_generator_test.rb b/railties/test/generators/task_generator_test.rb
index d5bd44b9db..5f162919d8 100644
--- a/railties/test/generators/task_generator_test.rb
+++ b/railties/test/generators/task_generator_test.rb
@@ -1,5 +1,7 @@
-require 'generators/generators_test_helper'
-require 'rails/generators/rails/task/task_generator'
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "rails/generators/rails/task/task_generator"
 
 class TaskGeneratorTest < Rails::Generators::TestCase
   include GeneratorsTestHelper
@@ -15,10 +17,10 @@ class TaskGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_task_on_revoke
-    task_path = 'lib/tasks/feeds.rake'
+    task_path = "lib/tasks/feeds.rake"
     run_generator
     assert_file task_path
-    run_generator ['feeds'], behavior: :revoke
+    run_generator ["feeds"], behavior: :revoke
     assert_no_file task_path
   end
 end
diff --git a/railties/test/generators/test_runner_in_engine_test.rb b/railties/test/generators/test_runner_in_engine_test.rb
index d37e261fbb..0e15b5e388 100644
--- a/railties/test/generators/test_runner_in_engine_test.rb
+++ b/railties/test/generators/test_runner_in_engine_test.rb
@@ -1,12 +1,14 @@
-require 'generators/plugin_test_helper'
+# frozen_string_literal: true
+
+require "generators/plugin_test_helper"
 
 class TestRunnerInEngineTest < ActiveSupport::TestCase
   include PluginTestHelper
 
   def setup
-    @destination_root = Dir.mktmpdir('bukkits')
+    @destination_root = Dir.mktmpdir("bukkits")
     Dir.chdir(@destination_root) { `bundle exec rails plugin new bukkits --full --skip-bundle` }
-    plugin_file 'test/dummy/db/schema.rb', ''
+    plugin_file "test/dummy/db/schema.rb", ""
   end
 
   def teardown
@@ -14,10 +16,10 @@ class TestRunnerInEngineTest < ActiveSupport::TestCase
   end
 
   def test_rerun_snippet_is_relative_path
-    create_test_file 'post', pass: false
+    create_test_file "post", pass: false
 
-    output = run_test_command('test/post_test.rb')
-    expect = %r{Running:\n\nPostTest\nF\n\nFailure:\nPostTest#test_truth \[[^\]]+test/post_test.rb:6\]:\nwups!\n\nbin/rails test test/post_test.rb:4}
+    output = run_test_command("test/post_test.rb")
+    expect = %r{Running:\n\nPostTest\nF\n\nFailure:\nPostTest#test_truth \[[^\]]+test/post_test\.rb:6\]:\nwups!\n\nbin/rails test test/post_test\.rb:4}
     assert_match expect, output
   end