redundant_pattern_matching does not check for match with single arm

[disco07]

Summary

Use of match, matching Result or Option; do not trigger clippy::redundant_pattern_matching

Reproducer

I tried this code:

match Err::<i32, i32>(55) {
        Ok(_) => true,
        _ => false,
    };

I expected to see this happen:

Err::<i32, i32>(55).is_ok();

Instead, this happened:

match Err::<i32, i32>(55) {
        Ok(_) => true,
        _ => false,
    };

Version

rustc 1.71.0-nightly (b628260df 2023-04-22)
binary: rustc
commit-hash: b628260df0587ae559253d8640ecb8738d3de613
commit-date: 2023-04-22
host: x86_64-unknown-linux-gnu
release: 1.71.0-nightly
LLVM version: 16.0.2

Additional Labels

No response

[disco07]

@xFrednet

[xFrednet]

Hey @disco07, thank you for the ticket :). Do you have a specific question related to it :)

[disco07]

@xFrednet Can I work on this ?

[xFrednet]

Yes, you're very welcome to! As a start, you can take a look at the lint code: https://github.com/rust-lang/rust-clippy/blob/master/clippy_lints/src/matches/redundant_pattern_match.rs

And look at the AST structure of the code you want to detect. For this, I recommend using #[clippy::dump] and running tool > clippy. See Playground. Example actually triggers the match_like_matches_macro lint.

I guess that the lint ignores the match, as it expects the Ok and Err branches, and not a wildcard. Maybe you just need to add a check for that :)

[disco07]

@rustbot claim

[disco07]

@rustbot claim