CONTRIBUTING.md

General

Before making a pull request, discuss your ideas in an issue. This repo is experimental. This repo uses the tic package for CI.

Adding new hooks

To create a new hook, have a look at the official documentation on creating new hooks, then have a look at existing hooks in this repo. The actual executables are defined in inst/bin/. In the script, you can expect the passed command line arguments to be all options, finally the files that should be processed with the hook.

For the scripts to become a hook, they need to be registered in .pre-commit-hooks.yaml. As R is not currently a supported language of pre-commit (https://github.com/pre-commit/pre-commit/issues/926), most hooks use language: script and then a shebang in the entrypoint script.

Testing hooks

Hooks should be tested by checking both the positive outcome (hook passes) and the negative outcome (hook fails) by adding two run_test() statements to ./tests/testthat/test-all.R. Look at existing examples and the documentation of run_test(). Note that this won't actually use pre-commit. It will simply call the hook script the same way as pre-commit would, with the difference that the test uses a path to the Rscript executable whereas with pre-commit, the shebang is needed. Hence, omitting the shebang in your script will indicated passed tests, but this will be false positive. Also, there is no easy way to test if a hook is correctly registered in .pre-commit-hooks.yaml

For this reason, always test the hook manually end-to-end with pre-commit try-repo as described in the documentation.

Summary

• add your script to in inst/bin and make it executable. Only R scripts are currently supported as testing is done with Rscript ....

• register hook in .pre-commit-hooks.yaml.

• add two unit tests, test manually with pre-commit try-repo.

• add a description of the new hook to the README.Rmd. Both description and yaml example code.