wildcard-enum-match-arm

Disallow wildcard arms when matching nominal enums

A wildcard arm accepts every future variant added to an enum without requiring the match to be revisited.
Instead, you SHOULD name every expected variant so exhaustiveness checking exposes additions.

- Category: suspicious
- Level: warning
- Fix: none
- Scope: module

Reported

enum Mode {
    Read = 1,
    Write = 2,
}

function describe(mode: Mode): string {
    return match (mode) {
        Mode.Read => "read"
        _ => "other"
    };
}
Accepted

enum Mode {
    Read = 1,
    Write = 2,
}

function describe(mode: Mode): string {
    return match (mode) {
        Mode.Read => "read"
        Mode.Write => "write"
    };
}
Prior art

- Clippy · wildcardenummatcharm

language/linter/src/rules/suspicious/wildcardenummatcharm.rs:6