When I declare modules like this

#[cfg(unix)]
pub mod stub_hal;

rustfmt will check module, irrespective of condition.

However, when I declare them using cfg-if crate rustfmt doesn't check module.

cfg_if! {
    if #[cfg(unix)] {
        pub mod stub_hal;
    }
}

Is is designed behavior? Or is macro parsing not implemented for now?

That's rustfmt 1.0.1-nightly (be13559 2018-12-10)