Concretize doesn't work with cfg_attr

[asomers]

The #[concretize] attribute isn't processed as a real Rust attribute. It's processed as text by Mockall, and used as a directive to tell it how to mock something that's already being mocked. That's why it must be used with its canonical name; you can't do use mockall::concretize as something_else. But as of this writing, Mockall doesn't process the text correctly if it appears within a cfg_attr directive. Instead, it passes it through in the emitted code, causing various compile failures. This example will trigger the problem.

use std::path::Path;

#[cfg(test)]
use mockall::{automock, concretize};

#[cfg_attr(test, automock)]
trait Foo {
    #[cfg_attr(test, concretize)]
    fn foo<P: AsRef<Path>>(&self, p: P);
}

First reported as https://github.com/asomers/mockall/pull/408#issuecomment-1312794561 .

[asomers]

@cjriches this should be fixed now.

[cjriches]

Thanks! Yup, seems to work now.

[horacimacias]

I'm trying to use this but if I understand correctly this concretize is on a non-released version of mockall. Any idea when a new release containing concretize will be available?

[asomers]

I've held off from releasing it because it's a big change, not just to the implementation but to the API. And it's a weird change, too. I haven't heard much feedback about it. Why don't you try it out, on the master branch, and let me know how it works for you?

[horacimacias]

sure, let me give it a try. thanks!