gistfile1.rb

describe SubjectsController do
  context "POST create" do
    it "creates a new record and shows it given valid attributes" do
      subject_attrs = Factory.attributes_for(:subject)
      post :create, subject: subject_attrs
      # The following line raises an exception:
      # Failure/Error: response.should redirect_to(:action => :show)
      #        Expected response to be a redirect to <http://test.host/assets?action=show&controller=subjects> but was a redirect to <http://test.host/subjects/1>
      response.should redirect_to(action: :show)
    end
  end
end

We figured this out when we got a similar error. It turned out our implementation was passing nil for an id in a call to url_for, which confused the router. The nil was thanks to an oversight when mocking the model for the test.