# Cargo Shear
Detect and remove unused dependencies from `Cargo.toml` in Rust projects.
## Usage
```bash
cargo install cargo-shear
cargo shear --fix
```
### Exit Code (for CI)
The exit code gives an indication whether unused dependencies have been found:
* 0 if found no unused dependencies,
* 1 if it found at least one unused dependency,
* 2 if there was an error during processing (in which case there's no indication whether any unused dependency was found or not).
## Technique
1. use the `cargo_metadata` crate to list all dependencies specified in `[workspace.dependencies]` and `[dependencies]`
2. iterate through all package targets to locate all Rust files
3. use `syn` to parse these Rust files and extract imports
4. identify the difference between the imports and the package dependencies
## TODO
- [ ] make the reporting more granular for `[dependencies]`, `[dev-dependencies]` and `[build-dependencies]`
- [ ] add tests
- [ ] print things nicely
- [ ] ignore `[package.metadata.cargo-shear] ignored = ["crate"]`
## Prior Arts
* https://github.com/est31/cargo-udeps
* https://github.com/bnjbvr/cargo-machete
## Trophy Cases
* -7 lines from [oxc](https://github.com/oxc-project/oxc/pull/2729)
* -59 lines from [rspack](https://github.com/web-infra-dev/rspack/pull/5954)
* -39 lines from [rolldown](https://github.com/rolldown/rolldown/pull/593)