rails new --api generates an api app skeleton

5 files changed, 87 insertions, 5 deletions

diff --git a/railties/lib/rails/generators.rb b/railties/lib/rails/generators.rb
index 79088bbe3c..96742dd2e6 100644
--- a/railties/lib/rails/generators.rb
+++ b/railties/lib/rails/generators.rb
@@ -45,6 +45,7 @@ module Rails
 
     DEFAULT_OPTIONS = {
       rails: {
+        api: false,
         assets: true,
         force_plural: false,
         helper: true,
diff --git a/railties/lib/rails/generators/app_base.rb b/railties/lib/rails/generators/app_base.rb
index c02b39d203..b85bf874a6 100644
--- a/railties/lib/rails/generators/app_base.rb
+++ b/railties/lib/rails/generators/app_base.rb
@@ -252,7 +252,7 @@ module Rails
       end
 
       def assets_gemfile_entry
-        return [] if options[:skip_sprockets]
+        return [] if options[:skip_sprockets] || options[:api]
 
         gems = []
         gems << GemfileEntry.version('sass-rails', '~> 5.0',
@@ -280,7 +280,7 @@ module Rails
       end
 
       def javascript_gemfile_entry
-        if options[:skip_javascript]
+        if options[:skip_javascript] || options[:api]
           []
         else
           gems = [coffee_gemfile_entry, javascript_runtime_gemfile_entry]
diff --git a/railties/lib/rails/generators/rails/app/app_generator.rb b/railties/lib/rails/generators/rails/app/app_generator.rb
index 152c26860e..6197b85bb6 100644
--- a/railties/lib/rails/generators/rails/app/app_generator.rb
+++ b/railties/lib/rails/generators/rails/app/app_generator.rb
@@ -175,6 +175,9 @@ module Rails
       class_option :version, type: :boolean, aliases: "-v", group: :rails,
                              desc: "Show Rails version number and quit"
 
+      class_option :api, type: :boolean,
+                         desc: "Preconfigure smaller stack for API only apps"
+
       def initialize(*args)
         super
 
@@ -245,11 +248,11 @@ module Rails
       end
 
       def create_tmp_files
-        build(:tmp)
+        build(:tmp) unless options[:api]
       end
 
       def create_vendor_files
-        build(:vendor)
+        build(:vendor) unless options[:api]
       end
 
       def delete_js_folder_skipping_javascript
diff --git a/railties/lib/rails/generators/rails/app/templates/app/controllers/application_controller.rb.tt b/railties/lib/rails/generators/rails/app/templates/app/controllers/application_controller.rb.tt
index d83690e1b9..f726fd6305 100644
--- a/railties/lib/rails/generators/rails/app/templates/app/controllers/application_controller.rb.tt
+++ b/railties/lib/rails/generators/rails/app/templates/app/controllers/application_controller.rb.tt
@@ -1,5 +1,7 @@
-class ApplicationController < ActionController::Base
+class ApplicationController < ActionController::<%= options[:api] ? "API" : "Base" %>
+<%- unless options[:api] -%>
   # Prevent CSRF attacks by raising an exception.
   # For APIs, you may want to use :null_session instead.
   protect_from_forgery with: :exception
+<%- end -%>
 end
diff --git a/railties/test/generators/api_app_generator_test.rb b/railties/test/generators/api_app_generator_test.rb
new file mode 100644
index 0000000000..d7121da45f
--- /dev/null
+++ b/railties/test/generators/api_app_generator_test.rb
@@ -0,0 +1,76 @@
+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']
+
+  def setup
+    Rails.application = TestApp::Application
+    super
+
+    Kernel::silence_warnings do
+      Thor::Base.shell.send(:attr_accessor, :always_force)
+      @shell = Thor::Base.shell.new
+      @shell.send(:always_force=, true)
+    end
+  end
+
+  def teardown
+    super
+    Rails.application = TestApp::Application.instance
+  end
+
+  def test_skeleton_is_created
+    run_generator
+
+    default_files.each { |path| assert_file path }
+    skipped_files.each { |path| assert_no_file path }
+  end
+
+  def test_api_modified_files
+    run_generator
+
+    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)
+    end
+    assert_file "app/controllers/application_controller.rb", /ActionController::API/
+  end
+
+  private
+
+  def default_files
+    files = %W(
+      .gitignore
+      Gemfile
+      Rakefile
+      config.ru
+      app/controllers
+      app/mailers
+      app/models
+      config/environments
+      config/initializers
+      config/locales
+      db
+      lib
+      lib/tasks
+      lib/assets
+      log
+      test/fixtures
+      test/controllers
+      test/integration
+      test/models
+    )
+    files.concat %w(bin/bundle bin/rails bin/rake)
+    files
+  end
+
+  def skipped_files
+    %w(vendor/assets
+       tmp/cache/assets)
+  end
+end