expect(response).to be 200 initiates lag and memory leak

[atomAltera]

Hello, I'm just begun learning controller testing with RSpec and accidently wrote

expect(response).to be 200

in place of

expect(response).to be_success

Full unit:

require 'spec_helper'

describe UserController do

  describe "GET 'show'" do
    it "assigns the requested user to @user" do
      user = create(:user)

      get :show, id: user.id

      expect(response).to be 200
      expect(response).to render_template :show

      expect(assigns :user).to eq user
    end
  end

end

Result is shown in image:

[myronmarston]

This is due a bug in either rack (see rack/rack#419) or rails (see rails/rails#13921 and rails/rails#13982) that causes [response].flatten to recurse infinitely. Both have been fixed (although I'm not sure if the rails fix has been released) but if you upgrade to versions that have fixes the problem will go away. In the meantime, make expectations about attributes of the response rather than on the response itself.

For more history/discussion see:

• Running rspec hangs #61
• `expect(response).to_eq('something') hangs if it's a redirect #667
• Controller specs: response.should == 'string' #613
• 100% CPU when comparing ActiveController::TestResponse with a primitive #601
• MRI out of memory (or segfault) when trying to compare controller response with Fixnum rspec-core#897
• memory leak in controller testing for json response rspec-expectations#289
• RSpec raises OutOfMemoryError rspec-expectations#166

[JonRowe]

Good catch @myronmarston