API apps scaffold generator generates an apropriate controller

railties/lib/rails/generators/rails/scaffold_controller/scaffold_controller_generator.rb

@@ -10,11 +10,14 @@ class ScaffoldControllerGenerator < NamedBase # :nodoc:
       class_option :helper, type: :boolean
       class_option :orm, banner: "NAME", type: :string, required: true,
                          desc: "ORM to generate the controller for"
+      class_option :api, type: :boolean,
+                         desc: "Preconfigure smaller stack for API only apps"
 
       argument :attributes, type: :array, default: [], banner: "field:type field:type"
 
       def create_controller_files
-        template "controller.rb", File.join('app/controllers', controller_class_path, "#{controller_file_name}_controller.rb")
+        template_file = options.api? ? "api_controller.rb" : "controller.rb"
+        template template_file, File.join('app/controllers', controller_class_path, "#{controller_file_name}_controller.rb")
       end
 
       hook_for :template_engine, :test_framework, as: :scaffold

railties/lib/rails/generators/rails/scaffold_controller/templates/api_controller.rb

@@ -0,0 +1,63 @@
+<% if  namespaced? -%>
+require_dependency "<%= namespaced_file_path %>/application_controller"
+
+<% end  -%>
+<% module_namespacing  do -%>
+class <%= controller_class_name %>Controller < ApplicationController
+  before_action :set_<%= singular_table_name %>, only: [:show, :update, :destroy]
+
+  # GET <%= route_url %>
+  def index
+    @<%= plural_table_name %> = <%= orm_class.all(class_name) %>
+
+    render json: <%= "@#{plural_table_name}" %>
+  end
+
+  # GET <%= route_url %>/1
+  def show
+    render json: <%= "@#{singular_table_name}" %>
+  end
+
+  # POST <%= route_url %>
+  def create
+    @<%= singular_table_name %> = <%= orm_class.build(class_name, "#{singular_table_name}_params") %>
+
+    if @<%= orm_instance.save %>
+      render json: <%= "@#{singular_table_name}" %>, status: :created, location: <%= "@#{singular_table_name}" %>
+    else
+      render json: <%= "@#{orm_instance.errors}" %>, status: :unprocessable_entity
+    end
+  end
+
+  # PATCH/PUT <%= route_url %>/1
+  def update
+    if @<%= orm_instance.update("#{singular_table_name}_params") %>
+      head :no_content
+    else
+      render json: <%= "@#{orm_instance.errors}" %>, status: :unprocessable_entity
+    end
+  end
+
+  # DELETE <%= route_url %>/1
+  def destroy
+    @<%= orm_instance.destroy %>
+
+    head :no_content
+  end
+
+  private
+    # Use callbacks to share common setup or constraints between actions.
+    def set_<%= singular_table_name %>
+      @<%= singular_table_name %> = <%= orm_class.find(class_name, "params[:id]") %>
+    end
+
+    # Only allow a trusted parameter "white list" through.
+    def <%= "#{singular_table_name}_params" %>
+      <%- if attributes_names.empty? -%>
+      params[:<%= singular_table_name %>]
+      <%- else -%>
+      params.require(:<%= singular_table_name %>).permit(<%= attributes_names.map { |name| ":#{name}" }.join(', ') %>)
+      <%- end -%>
+    end
+end
+<% end  -%>

railties/lib/rails/generators/test_unit/scaffold/scaffold_generator.rb

@@ -8,10 +8,14 @@ class ScaffoldGenerator < Base # :nodoc:
 
       check_class_collision suffix: "ControllerTest"
 
+      class_option :api, type: :boolean,
+                         desc: "Preconfigure smaller stack for API only apps"
+
       argument :attributes, type: :array, default: [], banner: "field:type field:type"
 
       def create_test_files
-        template "functional_test.rb",
+        template_file = options.api? ? "api_functional_test.rb" : "functional_test.rb"
+        template template_file,
                  File.join("test/controllers", controller_class_path, "#{controller_file_name}_controller_test.rb")
       end
 

railties/lib/rails/generators/test_unit/scaffold/templates/api_functional_test.rb

@@ -0,0 +1,41 @@
+require 'test_helper'
+
+<% module_namespacing  do -%>
+class <%= controller_class_name %>ControllerTest < ActionController::TestCase
+  setup do
+    @<%= singular_table_name %> = <%= table_name %>(:one)
+  end
+
+  test "should get index" do
+    get :index
+    assert_response :success
+    assert_not_nil assigns(:<%= table_name %>)
+  end
+
+  test "should create <%= singular_table_name %>" do
+    assert_difference('<%= class_name %>.count') do
+      post :create, params: { <%= "#{singular_table_name}: { #{attributes_hash} }" %> }
+    end
+
+    assert_response 201
+  end
+
+  test "should show <%= singular_table_name %>" do
+    get :show, params: { id: <%= "@#{singular_table_name}" %> }
+    assert_response :success
+  end
+
+  test "should update <%= singular_table_name %>" do
+    patch :update, params: { id: <%= "@#{singular_table_name}" %>, <%= "#{singular_table_name}: { #{attributes_hash} }" %> }
+    assert_response 204
+  end
+
+  test "should destroy <%= singular_table_name %>" do
+    assert_difference('<%= class_name %>.count', -1) do
+      delete :destroy, params: { id: <%= "@#{singular_table_name}" %> }
+    end
+
+    assert_response 204
+  end
+end
+<% end  -%>

railties/test/application/rake_test.rb

@@ -194,6 +194,26 @@ def test_scaffold_tests_pass_by_default
       assert_no_match(/Errors running/, output)
     end
 
+    def test_api_scaffold_tests_pass_by_default
+      add_to_config <<-RUBY
+        config.api_only = true
+        config.generators.api_only = true
+      RUBY
+
+      app_file "app/controllers/application_controller.rb", <<-RUBY
+        class ApplicationController < ActionController::API
+        end
+      RUBY
+
+      output = Dir.chdir(app_path) do
+        `rails generate scaffold user username:string password:string;
+         bundle exec rake db:migrate test`
+      end
+
+      assert_match(/5 runs, 8 assertions, 0 failures, 0 errors/, output)
+      assert_no_match(/Errors running/, output)
+    end
+
     def test_scaffold_with_references_columns_tests_pass_when_belongs_to_is_optional
       app_file "config/initializers/active_record_belongs_to_required_by_default.rb",
         "Rails.application.config.active_record.belongs_to_required_by_default = false"

railties/test/generators/scaffold_controller_generator_test.rb

@@ -185,4 +185,51 @@ def test_controller_tests_pass_by_default_inside_mountable_engine
       assert_match(/2 runs, 2 assertions, 0 failures, 0 errors/, `bundle exec rake test 2>&1`)
     end
   end
+
+  def test_api_only_generates_a_proper_api_controller
+    run_generator ["User", "--api"]
+
+    assert_file "app/controllers/users_controller.rb" do |content|
+      assert_match(/class UsersController < ApplicationController/, content)
+      assert_no_match(/respond_to/, content)
+
+      assert_match(/before_action :set_user, only: \[:show, :update, :destroy\]/, content)
+
+      assert_instance_method :index, content do |m|
+        assert_match(/@users = User\.all/, m)
+        assert_match(/render json: @users/, m)
+      end
+
+      assert_instance_method :show, content do |m|
+        assert_match(/render json: @user/, m)
+      end
+
+      assert_instance_method :create, content do |m|
+        assert_match(/@user = User\.new\(user_params\)/, m)
+        assert_match(/@user\.save/, m)
+        assert_match(/@user\.errors/, m)
+      end
+
+      assert_instance_method :update, content do |m|
+        assert_match(/@user\.update\(user_params\)/, m)
+        assert_match(/@user\.errors/, m)
+      end
+
+      assert_instance_method :destroy, content do |m|
+        assert_match(/@user\.destroy/, m)
+      end
+    end
+  end
+
+  def test_api_controller_tests
+    run_generator ["User", "name:string", "age:integer", "organization:references{polymorphic}", "--api"]
+
+    assert_file "test/controllers/users_controller_test.rb" do |content|
+      assert_match(/class UsersControllerTest < ActionController::TestCase/, content)
+      assert_match(/test "should get index"/, content)
+      assert_match(/post :create, params: \{ user: \{ age: @user\.age, name: @user\.name, organization_id: @user\.organization_id, organization_type: @user\.organization_type \} \}/, content)
+      assert_match(/patch :update, params: \{ id: @user, user: \{ age: @user\.age, name: @user\.name, organization_id: @user\.organization_id, organization_type: @user\.organization_type \} \}/, content)
+      assert_no_match(/assert_redirected_to/, content)
+    end
+  end
 end