buggy formatting on expression attributes with comments

[meetmangukiya]

Example code:

#![feature(stmt_expr_attributes)]
fn main() {
    let some_function_call = || {};

    let filter = || {
        (
            // comment
            #[allow(clippy::disallowed_methods)]
            some_function_call()
        )
    };
}

Everytime you format it it replicates the attribute and doubles it:

#![feature(stmt_expr_attributes)]
fn main() {
    let some_function_call = || {};

    let filter = || {
        (
            // comment
            #[allow(clippy::disallowed_methods)]
            #[allow(clippy::disallowed_methods)]
            some_function_call()
        )
    };
}

Version: rustfmt 1.6.0-nightly (39f42ad9 2023-07-19)

[ytmimi]

Thanks for the report!

Confirming that I can reproduce this with rustfmt 1.6.0-nightly (a9ae7462 2023-07-19). I don't have time to look into the details right now, but I'll follow up once I've had a chance to dig into this.

[ytmimi]

The input without the parens doesn't seem to have the issue so wrapping the call in parens seems to be trigging this issue.

#![feature(stmt_expr_attributes)]
fn main() {
    let some_function_call = || {};

    let filter = || {
        // comment
        #[allow(clippy::disallowed_methods)]
        some_function_call()
    };
}