Thanks for wanting to contribute!
If you want help or mentorship, please file a Github issue and I'll be sure to provide guidance to the best of my ability.
Otherwise be sure to check out ARCHITECTURE.md for an overview on the internals.
Check out Servo's Github workflow for an overview on creating a pull request.
Don't worry about requesting code review, as there is nothing formally setup for this repository. I try and review each pull request as soon as I can.
There is continuous integration setup for cbindgen using travis. It automatically runs cargo test which runs cbindgen against a series of rust files from tests/rust/ and checks that the output compiles using gcc or g++.
Please run cargo test before filing a pull request to be sure that all tests pass. This will also update the test expectations.
Rustfmt is also enforced by travis. To format your code install rustfmt-preview using rustup component add rustfmt-preview and then cargo fmt. Travis runs with rust nightly, so use rustup run nightly -- cargo fmt to guarantee consistent results.
Writing new tests with your pull requests is also appreciated.