RecordNotFound raised when using find_by_id to get non-existent record in RSpec

Question

I've written this spec in products_controller_spec.rb, that is intended to test a redirect when destroy is called on a non-existent record:

it "deleting a non-existent product should redirect to the user's profile page with a flash error" do           
    delete :destroy, {:id => 9999}
    response.should redirect_to "/profile"
    flash[:error].should == I18n.t(:slideshow_was_not_deleted)
end

Here's the controller action in products_controller.rb:

def destroy
  product = Product.find_by_id(params[:id])
  redirect_to "profile" if !product
  if product.destroy
    flash[:notice] = t(:slideshow_was_deleted)
    if current_user.admin? and product.user != current_user
      redirect_to :products, :notice => t(:slideshow_was_deleted)
    else
      redirect_to "/profile"
    end
  else
    if current_user.admin?
      redirect_to :products, :error => t(:slideshow_was_not_deleted)
    else
      redirect_to "/profile"
    end
  end
end

Now, I didn't expect the spec to pass first time but I don't understand why it's failing with this:

Failure/Error: delete :destroy, {:id => 9999}
 ActiveRecord::RecordNotFound:
   Couldn't find Product with id=9999

I was under the impression that #find_by_id would not return RecordNotFound error on a non-existent record. So why am I getting one? Thanks in advance!

Answer 1

The RecordNotFound error was being thrown by CanCan. It's not rescue-able from within the controller action (presumably it occurs before the action runs). There were two ways of resolving it -

1. Changing the spec to:

   it "deleting a non-existent product should result in a RecordNotFound Error" do         
     product_id = 9999
     expect { delete :destroy, {:id => product_id}}.to raise_error ActiveRecord::RecordNotFound
   end
   

or, 2. Patching CanCan like this.

I didn't fancy the patching route, so I went for option 1.