Discussion: my way of testing rescue_from in Rails

I used to rescue an Exception like this:

unless Rails.application.config.consider_all_requests_local

rescue_from Exception, :with => :render_error

end

But this is hard to test.

So I removed the condition in the controller and added it in the
render_error method itself: raise e if request.local?

And in my test I overwrite ActionDispatch::Request

class ::ActionDispatch::Request

def local? ; false end
end

What do you think?