Specs for Helpers that call render

Testing RSpec
1

The helper spec I am writing tests a helper method that calls render.

module HelperHelper
def render_partial
render :partial => ‘partial’
end
end

The helper spec.

describe HelperHelper do
it “should render partial” do
render_partial.should_not == nil
end
end

The output generated

$ spec spec/helpers/home_helper_spec.rb
.F

NoMethodError in ‘HelperHelper should render partial’
You have a nil object when you didn’t expect it!
The error occurred while evaluating nil.render
app/helpers/helper_helper.rb:4:in `render_partial’
./spec/helpers/helper_helper_spec.rb:3:

Finished in 0.00000 seconds

1 example, 1 failure

I tried adding a before(:each) to setup response, controller, and
template objects that render would be called on but the error was
always the same. I am still uncertain I did this correctly although
I did spend some time looking at the render definition in the rails
source.

Is there a standard way of setting up specs for helpers that call
render?

  • Peter

(I apologize if this has already been answered. We spent a good deal
of time searching around the web for a solution but came up empty so
far.)

2

On Nov 2, 2007 8:32 PM, Peter [email protected] wrote:

The helper spec.

Is there a standard way of setting up specs for helpers that call
render?

Helper specs create an object to run in and include a standard set of
helpers and the helper you are spec’ing. There is no access to
services that come from the controllers or views the helper gets mixed
into when the app is running.

I would just set a message expectation on self, like this:

describe HelperHelper do
it “should render partial” do
self.should_receive(:render).with(:partial => ‘partial’)
render_partial
end
end

HTH,
David