Add a generic --skip-gems options to generator

Also remove --skip-turbolinks.

This option is useful if users want to remove some gems like jbuilder,
turbolinks, coffee-rails, etc that don't have specific options on the
generator.

    rails new my_app --skip-gems turbolinks coffee-rails

railties/CHANGELOG.md

+*   Add a generic --skip-gems options to generator
+
+    This option is useful if users want to remove some gems like jbuilder,
+    turbolinks, coffee-rails, etc that don't have specific options on the
+    generator.
+
+        rails new my_app --skip-gems turbolinks coffee-rails
+
+    *Rafael Mendonça França*
+
 *   Invalid `bin/rails generate` commands will now show spelling suggestions.
 
     *Richard Schneeman*

railties/lib/rails/generators/app_base.rb

@@ -41,6 +41,9 @@ def self.add_shared_options_for(name)
         class_option :skip_active_record, type: :boolean, aliases: '-O', default: false,
                                           desc: 'Skip Active Record files'
 
+        class_option :skip_gems,          type: :array, default: [],
+                                          desc: 'Skip the provided gems files'
+
         class_option :skip_action_view,   type: :boolean, aliases: '-V', default: false,
                                           desc: 'Skip Action View files'
 
@@ -50,9 +53,6 @@ def self.add_shared_options_for(name)
         class_option :skip_spring,        type: :boolean, default: false,
                                           desc: "Don't install Spring application preloader"
 
-        class_option :skip_turbolinks,    type: :boolean, default: false,
-                                          desc: "Don't install Turbolinks"
-
         class_option :database,           type: :string, aliases: '-d', default: 'sqlite3',
                                           desc: "Preconfigure for selected database (options: #{DATABASES.join('/')})"
 
@@ -82,7 +82,7 @@ def self.add_shared_options_for(name)
       end
 
       def initialize(*args)
-        @gem_filter    = lambda { |gem| true }
+        @gem_filter    = lambda { |gem| !options[:skip_gems].include?(gem.name) }
         @extra_entries = []
         super
         convert_database_option_for_jruby
@@ -290,10 +290,8 @@ def javascript_gemfile_entry
           gems << GemfileEntry.version("#{options[:javascript]}-rails", nil,
                                  "Use #{options[:javascript]} as the JavaScript library")
 
-          unless options[:skip_turbolinks]
-            gems << GemfileEntry.version("turbolinks", nil,
-              "Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks")
-          end
+          gems << GemfileEntry.version("turbolinks", nil,
+            "Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks")
           gems
         end
       end

railties/test/generators/app_generator_test.rb

@@ -448,11 +448,12 @@ def test_skip_spring
     end
   end
 
-  def test_skip_turbolinks
-    run_generator [destination_root, "--skip-turbolinks"]
+  def test_generator_if_skip_gems_is_given
+    run_generator [destination_root, "--skip-gems", "turbolinks", "coffee-rails"]
 
     assert_file "Gemfile" do |content|
       assert_no_match(/turbolinks/, content)
+      assert_no_match(/coffee-rails/, content)
     end
     assert_file "app/views/layouts/application.html.erb" do |content|
       assert_no_match(/data-turbolinks-track/, content)