Supplemental pre-commit hook to run cargo clippy --fix, silencing its stderr unless an error prevents Clippy from exiting correctly. Intended to be used together with regular cargo clippy call that would list warnings as usual. Since there seems to be no way to make --fix explain what and why it fixes.

Add the hook to your .pre-commit-config.yaml after your regular Clippy hook. Order is important as pre-commit runs hooks one by one in the way they were listed in the config file.

repos:
  - repo: https://github.com/doublify/pre-commit-rust
    rev: v1.0
    hooks:
      - id: clippy
  - repo: https://github.com/Artalus/pre-commit-clippy-fix
    rev: v0.1
    hooks:
      - id: clippy-fix

• If Clippy has nothing to fix, it will exit with code 0 and the hook will succeed.
• If there were any changes applied, Clippy still will exit with 0, but the hook will fail detecting a change in workdir:

clippy fix...............................................................Failed
- hook id: clippy-fix
- duration: 2.12s
- files were modified by this hook

• If Clippy actually fails with non-zero exit code, the hook will dump the stderr:

clippy fix...............................................................Failed
- hook id: clippy-fix
- duration: 0.25s
- exit code: 101

cargo clippy --fix --allow-staged exited with 101; STDERR was:

error: invalid table header
expected `.`, `]`
 --> Cargo.toml:1:11
  |
1 | [workspace
  |           ^

As with any other pre-commit hook, you can use args to pass additional arguments to Clippy:

      - id: clippy-fix
        args: [--all-targets, --no-deps, --, -D, warnings]