Make sure respond_with with :js tries to render a template in all cases

actionpack/CHANGELOG

@@ -30,6 +30,8 @@
 
 *Rails 3.1.0 (unreleased)*
 
+* Make sure respond_with with :js tries to render a template in all cases [José Valim]
+
 * json_escape will now return a SafeBuffer string if it receives SafeBuffer string [tenderlove]
 
 * Make sure escape_js returns SafeBuffer string if it receives SafeBuffer string [Prem Sichanugrist]

actionpack/lib/action_controller/metal/responder.rb

@@ -162,6 +162,11 @@ module ActionController #:nodoc:
       navigation_behavior(e)
     end
 
+    # to_js simply tries to render a template. If no template is found, raises the error.
+    def to_js
+      default_render
+    end
+
     # All other formats follow the procedure below. First we try to render a
     # template, if the template is not available, we verify if the resource
     # responds to :to_format and display it.

actionpack/test/controller/mime_responds_test.rb

@@ -509,7 +509,7 @@ end
 class RespondWithController < ActionController::Base
   respond_to :html, :json
   respond_to :xml, :except => :using_resource_with_block
-  respond_to :js,  :only => [ :using_resource_with_block, :using_resource ]
+  respond_to :js,  :only => [ :using_resource_with_block, :using_resource, :using_hash_resource ]
 
   def using_resource
     respond_with(resource)
@@ -575,11 +575,6 @@ protected
   def resource
     Customer.new("david", request.delete? ? nil : 13)
   end
-
-  def _render_js(js, options)
-    self.content_type ||= Mime::JS
-    self.response_body = js.respond_to?(:to_js) ? js.to_js : js
-  end
 end
 
 class InheritedRespondWithController < RespondWithController
@@ -638,6 +633,20 @@ class RespondWithControllerTest < ActionController::TestCase
     end
   end
 
+  def test_using_resource_with_js_simply_tries_to_render_the_template
+    @request.accept = "text/javascript"
+    get :using_resource
+    assert_equal "text/javascript", @response.content_type
+    assert_equal "alert(\"Hi\");", @response.body
+  end
+
+  def test_using_hash_resource_with_js_raises_an_error_if_template_cant_be_found
+    @request.accept = "text/javascript"
+    assert_raise ActionView::MissingTemplate do
+      get :using_hash_resource
+    end
+  end
+
   def test_using_hash_resource
     @request.accept = "application/xml"
     get :using_hash_resource

actionpack/test/fixtures/respond_with/using_resource.js.erb

@@ -0,0 +1 @@
+alert("Hi");