#[expect(...)] attribute not working for clippy::assertion_on_constant

[ethanmsl]

Summary

#[expect(clippy::assertions_on_constants)]

Does not work to prevent clippy warning for same.
(Not sure if clippy warnings use compiled code or just raw code; if latter perhaps ordering of run is relevant - with expect notation being applied to code that's been optimized away?)

e.g.

#[cfg(test)]
mod tests {
        #[test]
        fn test_truth() {
                #[expect(clippy::assertions_on_constants)]
                assert!(true);
        }
}

Reproducer

I tried this code:

fn main() {
        // unused attribute `expect`
        // `#[warn(unused_attributes)]` on by default
        #[expect(clippy::assertions_on_constants)]
        assert!(true);
        // `assert!(true)` will be optimized out by the compiler
        // remove it
        // for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#assertions_on_constants
        // `#[warn(clippy::assertions_on_constants)]` on by default
}

I expected to see this happen:
the expect annotation of clippy warning prevent the clippy warning

Instead, this happened:
clippy warning remained and a new clippy warning mentioning that the expect had no effect

Version

rustc 1.85.0-nightly (28fc2ba71 2024-11-24)
binary: rustc
commit-hash: 28fc2ba7142654fa6e654926f96ff913027b200e
commit-date: 2024-11-24
host: aarch64-apple-darwin
release: 1.85.0-nightly
LLVM version: 19.1.4

Note, if relevant:
cargo.toml also contains:

cargo-features = ["edition2024"]
#...
[package]
#...
edition = "2024"

Additional Labels

No response

[ethanmsl]

On further investigation this appears to be related to the currently open issue: rust-clippy/issues/10355

Looking at the clippy warning in terminal gave additional context:

note: the built-in attribute `expect` will be ignored, since it's applied to the macro invocation `assert`
 --> src/bin/min_example.rs:5:9
  |
5 |         assert!(true);
  |         ^^^^^^
  = note: `#[warn(unused_attributes)]` on by default

The underlying issue then appears to simple be that attributes are not applied to macros.
I'll leave this here for someone else to close as redundant with the above issue (10355), just in case.

---

A workaround is simple to apply the #[expect(...)] to brackets {...} around the macro:

        #[expect(clippy::assertions_on_constants)]
        {
                assert!(true);
        }