RunTimeError: ActionController::RackDelegation in rspec 2.10.1 for rails 3.1.4 application controller

问题

In our rails 3.1.4 app, rspec is used to test the public method require_signin in application controller. Here is the method require_signin:

  def require_signin
    if !signed_in?  
      flash.now.alert = "Log in first!"
      redirect_to signin_path
    end
  end  

Here is the rspec code:

it "should invoke require_signin for those without login" do
  controller.send(:require_signin)
  controller {should redirect_to signin_path}  
end

The above rspec generates gigantic multi pages error starting like the below:

RuntimeError:←[0m
       ←[31mActionController::RackDelegation#status= delegated to @_response.status=, but @_response is nil: #<ApplicationController:0x3
a67f10 @_routes=nil, @_action_has_layout=true, @_view_context_class=nil, @_headers={"Content-Type"=>"text/html"}, @_status=200, @_reques
t=#<ActionController::TestRequest:0x3a68720 @env={"rack.version"=>[1, 1], "rack.input"=>#<StringIO:0x34fad60>, ........

What could be wrong with the rspec code? Thanks so much.

回答1:

I came across this errror and realized I was triggering a redirect on the controller by calling a helper method I wanted to test, but I hadn't actually instantiated a test request yet. Calling get :index before calling the expectation got rid of the error.

it "redirects if some condition" do
  subject.send(:helper_method)
  get :action # <= Need this before setting expectation below
  response.should redirect_to("/somewhere")
end

回答2:

If you want to check action mechanics, you should use should_receive before a send call like this

it "should redirect to signin_path" do
  controller.should_receive(:redirect_to).with(signin_path)
  controller.send(:require_signin) 
end

回答3:

Might not be entirely useful, but I came here after getting the same error. I started with a passing test suite, made some changes, and then started getting errors like:

RuntimeError:
    ActionController::RackDelegation#status= delegated to @_response.status=, but @_response is nil:
    ...many lines...

After taking a closer look at the error, I noticed that it said somewhere:

@flashes={:alert=>"You have to confirm your account before continuing."}

I had just added the :confirmable option in Devise, and realized that all users that I created that I was trying to sign in as were unconfirmed, and as such could not successfully log in. I needed to add confirmed_at Time.now to my factory/fixture creation for users. In your example though, it seems like you are trying to test when not logged in, so I'm not sure this is necessarily applicable.

来源：https://stackoverflow.com/questions/10989461/runtimeerror-actioncontrollerrackdelegation-in-rspec-2-10-1-for-rails-3-1-4-a