[RSpec] mock_model not returning a mock

I’m experiencing some strange behaviour with an ActiveRecord model
object. I’m trying to spec that a mocked AR object, @form, has an
error on the “file” attribute.

I’ve confirmed that there is an error on the “file” attribute,
because I print out the error.

However, the spec fails, saying that one error was expected, but zero
were found.

I’ve pasted some code to help with figuring this out:

One thing that I’ve noticed is that if I comment this out in my spec:
195 @form.valid?
then the spec passes.

Any idea what’s going on? I’d really appreciate any help at all, as
I’ve been banging my head against this for a while, now.

Ack, that subject is completely wrong! I forgot to update it after re-
writing the email.