Question

I have a class method which I would like to mock and return one of the arguments that was passed in. Something like this in my code:

converted_data = Myclass.convert(arg, some_other_arg, data)

And in my test I would like to be able to do the following (although this doesn’t work).

Myclass.should_receive(:convert).with(*args).and_return(args[2])

So the method doesn’t actually do anything! If I run as written above, I get an error that it doesn’t know what args is to return it.

Answer 1

I found the answer:

@something.should_receive(:method).with(any_args()).and_return { |*args| args }

To return a specific argument, pick it from the array within the and_return block! So for your example, it would be:

Myclass.should_receive(:convert).with(any_args()).and_return { |*args| args[2] }

You likely want to do this on an instance of Myclass.