Testing cookies.permanent.signed

Hi,

When using:

def some_action cookies.permanent.signed[:cookie_name] = "somevalue" end

How do I test it in functional tests?

I'm trying to user:

assert_equal "somevalue", cookies.permanent.signed[:cookie_name] but I'm getting

NoMethodError: undefined method `permanent' for #<Hash:0x9955598>

Thanks,

Anyone knows how to test cookies.permanent?