The application builder allows you to override elements of the application generator without being forced to reverse the operations of the default generator.

This allows you to override entire operations, like the creation of the Gemfile, README, or JavaScript files, without needing to know exactly what those operations do so you can create another template action.

class CustomAppBuilder < Rails::AppBuilder
  def test
    @generator.gem "rspec-rails", group: [:development, :test]
    run "bundle install"
    generate "rspec:install"
  end
end

Methods

Instance Public methods

app()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 82
def app
  directory "app"

  empty_directory_with_keep_file "app/assets/images"

  keep_file  "app/controllers/concerns"
  keep_file  "app/models/concerns"
end

bin()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 91
def bin
  directory "bin" do |content|
    "#{shebang}\n" + content
  end
  chmod "bin", 0755 & ~File.umask, verbose: false
end

bin_when_updating()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 98
def bin_when_updating
  bin
end

config()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 102
def config
  empty_directory "config"

  inside "config" do
    template "routes.rb" unless options[:updating]
    template "application.rb"
    template "environment.rb"
    template "cable.yml" unless options[:updating] || options[:skip_action_cable]
    template "puma.rb"   unless options[:updating]
    template "storage.yml" unless options[:updating] || skip_active_storage?

    directory "environments"
    directory "initializers"
    directory "locales" unless options[:updating]
  end
end

config_target_version()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 252
def config_target_version
  defined?(@config_target_version) ? @config_target_version : Rails::VERSION::STRING.to_f
end

config_when_updating()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 119
def config_when_updating
  action_cable_config_exist       = File.exist?("config/cable.yml")
  active_storage_config_exist     = File.exist?("config/storage.yml")
  rack_cors_config_exist          = File.exist?("config/initializers/cors.rb")
  assets_config_exist             = File.exist?("config/initializers/assets.rb")
  asset_manifest_exist            = File.exist?("app/assets/config/manifest.js")
  asset_app_stylesheet_exist      = File.exist?("app/assets/stylesheets/application.css")
  csp_config_exist                = File.exist?("config/initializers/content_security_policy.rb")
  permissions_policy_config_exist = File.exist?("config/initializers/permissions_policy.rb")

  @config_target_version = Rails.application.config.loaded_config_version || "5.0"

  config

  if !options[:skip_action_cable] && !action_cable_config_exist
    template "config/cable.yml"
  end

  if !skip_active_storage? && !active_storage_config_exist
    template "config/storage.yml"
  end

  if skip_sprockets? && !assets_config_exist
    remove_file "config/initializers/assets.rb"
  end

  if skip_sprockets? && !asset_manifest_exist
    remove_file "app/assets/config/manifest.js"
  end

  if skip_sprockets? && !asset_app_stylesheet_exist
    remove_file "app/assets/stylesheets/application.css"
  end

  unless rack_cors_config_exist
    remove_file "config/initializers/cors.rb"
  end

  if options[:api]
    unless csp_config_exist
      remove_file "config/initializers/content_security_policy.rb"
    end

    unless permissions_policy_config_exist
      remove_file "config/initializers/permissions_policy.rb"
    end
  end

  if !skip_sprockets?
    insert_into_file "config/application.rb", %(require "sprockets/railtie"), after: /require\(["']rails\/all["']\)\n/
  end
end

configru()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 61
def configru
  template "config.ru"
end

credentials()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 181
def credentials
  return if options[:pretend] || options[:dummy_app]

  require "rails/generators/rails/credentials/credentials_generator"
  Rails::Generators::CredentialsGenerator.new([], quiet: options[:quiet]).add_credentials_file_silently
end

database_yml()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 188
def database_yml
  template "config/databases/#{options[:database]}.yml", "config/database.yml"
end

db()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 192
def db
  directory "db"
end

db_when_updating()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 196
def db_when_updating
  path = File.expand_path("db/schema.rb", destination_root)

  if File.exist?(path)
    gsub_file("db/schema.rb", /ActiveRecord::Schema\.define/, "ActiveRecord::Schema[6.1].define")
  end
end

gemfile()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 57
def gemfile
  template "Gemfile"
end

gitattributes()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 69
def gitattributes
  template "gitattributes", ".gitattributes"
end

gitignore()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 65
def gitignore
  template "gitignore", ".gitignore"
end

lib()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 204
def lib
  empty_directory "lib"
  empty_directory_with_keep_file "lib/tasks"
  empty_directory_with_keep_file "lib/assets"
end

log()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 210
def log
  empty_directory_with_keep_file "log"
end

master_key()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 172
def master_key
  return if options[:pretend] || options[:dummy_app]

  require "rails/generators/rails/master_key/master_key_generator"
  master_key_generator = Rails::Generators::MasterKeyGenerator.new([], quiet: options[:quiet], force: options[:force])
  master_key_generator.add_master_key_file_silently
  master_key_generator.ignore_master_key_file_silently
end

public_directory()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 214
def public_directory
  directory "public", "public", recursive: false
end

rakefile()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 45
def rakefile
  template "Rakefile"
end

readme()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 49
def readme
  copy_file "README.md", "README.md"
end

ruby_version()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 53
def ruby_version
  template "ruby-version", ".ruby-version"
end

storage()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 218
def storage
  empty_directory_with_keep_file "storage"
  empty_directory_with_keep_file "tmp/storage"
end

system_test()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 235
def system_test
  empty_directory_with_keep_file "test/system"

  template "test/application_system_test_case.rb"
end

test()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 223
def test
  empty_directory_with_keep_file "test/fixtures/files"
  empty_directory_with_keep_file "test/controllers"
  empty_directory_with_keep_file "test/mailers"
  empty_directory_with_keep_file "test/models"
  empty_directory_with_keep_file "test/helpers"
  empty_directory_with_keep_file "test/integration"

  template "test/channels/application_cable/connection_test.rb"
  template "test/test_helper.rb"
end

tmp()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 241
def tmp
  empty_directory_with_keep_file "tmp"
  empty_directory_with_keep_file "tmp/pids"
  empty_directory "tmp/cache"
  empty_directory "tmp/cache/assets"
end

vendor()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 248
def vendor
  empty_directory_with_keep_file "vendor"
end

version_control()

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 73
def version_control
  if !options[:skip_git] && !options[:pretend]
    run "git init", capture: options[:quiet], abort_on_failure: false
    if user_default_branch.strip.empty?
      `git symbolic-ref HEAD refs/heads/main`
    end
  end
end