# Contributing
New commits must follow [Conventional Commits](https://www.conventionalcommits.org/):
```text
<type>[optional scope][!]: <description>
```
Use `feat`, `fix`, `docs`, `style`, `refactor`, `perf`, `test`, `build`, `ci`,
`chore`, or `revert`. For example:
```text
fix(serde): handle empty arrays
ci: update the Windows runner
feat!: change the parser API
```
Install Cocogitto and enable the local commit message hook:
```sh
mise install cocogitto
mise run setup-hooks
```
Normal `git commit` commands are then checked before the commit is created.
Alternatively, use `cog commit` to compose a conventional message.
To run the same history check as CI:
```sh
mise run check-commits
```
The fixed `conventional-commits-start` tag marks the commit introducing this
policy. Earlier history is excluded; old messages do not need to be rewritten.
Keep this tag when cloning or fetching,
and do not move it. It is a migration marker, not a release tag.
CI checks all new non-merge commits on master pushes and pull requests. Git-generated
merge commits are ignored. When squash-merging, use a conventional PR title as
the resulting commit message. Hooks are local to each clone, so contributors
must install them once; CI also checks commits made without the hook.
## Development tasks
Run `mise tasks` to list the available tasks:
```sh
mise run bench
mise run copy-compile-commands
```
The benchmark task enables the `native` feature for C++ compilation. Copy
`.cargo/config.toml.example` to `.cargo/config.toml` to also tune the Rust code
for your CPU. The compilation database task copies CMake's generated
`compile_commands.json` from `target/` into `simdjson-sys/` for editor tooling.
## CI coverage
Linux (GCC and LLVM) and Windows (MSVC and LLVM) run on pull requests and pushes
to `master`. Feature branch pushes are checked through their PR, avoiding a
second run for the same update. macOS runs only on pushes to `master` or when CI is manually triggered
from the Actions page. New pushes cancel outdated runs for the same branch or PR.
Rust dependencies and build outputs are cached by
`actions-rust-lang/setup-rust-toolchain`, with separate keys for C++ compilers.
The Linux GCC job also checks optional features and verifies both release
packages without uploading. A Linux job checks Rust 1.88, the minimum supported
version. See [RELEASING.md](RELEASING.md) for the release procedure and run
`mise run release-check` before proposing a release.