helix-mods/docs/CONTRIBUTING.md

# Contributing

Contributors are very welcome! **No contribution is too small and all contributions are valued.**

Some suggestions to get started:

- You can look at the [good first issue][good-first-issue] label on the issue tracker.
- Help with packaging on various distributions needed!
- To use print debugging to the [Helix log file][log-file], you must:
  * Print using `log::info!`, `warn!`, or `error!`. (`log::info!("helix!")`)
  * Pass the appropriate verbosity level option for the desired log level. (`hx -v <file>` for info, more `v`s for higher verbosity)
  * Want to display the logs in a separate file instead of using the `:log-open` command in your compiled Helix editor? Start your debug version with `cargo run -- --log foo.log` and in a new terminal use `tail -f foo.log`
- Instead of running a release version of Helix, while developing you may want to run in debug mode with `cargo run` which is way faster to compile
- Looking for even faster compile times? Give a try to [mold](https://github.com/rui314/mold)
- If your preferred language is missing, integrating a tree-sitter grammar for
    it and defining syntax highlight queries for it is straight forward and
    doesn't require much knowledge of the internals.

We provide an [architecture.md][architecture.md] that should give you
a good overview of the internals.

# Auto generated documentation

Some parts of [the book][docs] are autogenerated from the code itself,
like the list of `:commands` and supported languages. To generate these
files, run

```shell
cargo xtask docgen
```

inside the project. We use [xtask][xtask] as an ad-hoc task runner.

To preview the book itself, install [mdbook][mdbook]. Then, run

```shell
mdbook serve book
```

and visit [http://localhost:3000](http://localhost:3000).

# Testing

## Unit tests/Documentation tests

Run `cargo test --workspace` to run unit tests and documentation tests in all packages.

## Integration tests

Integration tests for helix-term can be run with `cargo integration-test`. Code
contributors are strongly encouraged to write integration tests for their code.
Existing tests can be used as examples. Helpers can be found in
[helpers.rs][helpers.rs]. The log level can be set with the `HELIX_LOG_LEVEL`
environment variable, e.g. `HELIX_LOG_LEVEL=debug cargo integration-test`.

Contributors using MacOS might encounter `Too many open files (os error 24)`
failures while running integration tests. This can be resolved by increasing
the default value (e.g. to `10240` from `256`) by running `ulimit -n 10240`.

## Minimum Stable Rust Version (MSRV) Policy

Helix follows the MSRV of Firefox.
The current MSRV and future changes to the MSRV are listed in the [Firefox documentation].

[Firefox documentation]: https://firefox-source-docs.mozilla.org/writing-rust-code/update-policy.html
[good-first-issue]: https://github.com/helix-editor/helix/labels/E-easy
[log-file]: https://github.com/helix-editor/helix/wiki/FAQ#access-the-log-file
[architecture.md]: ./architecture.md
[docs]: https://docs.helix-editor.com/
[xtask]: https://github.com/matklad/cargo-xtask
[mdbook]: https://rust-lang.github.io/mdBook/guide/installation.html
[helpers.rs]: ../helix-term/tests/test/helpers.rs