How to add support for a language? #926

Activity

1. asottile

   added

   question

   on Jan 29, 2019
2. asottile commented on Jan 29, 2019

   

   asottile

   on Jan 29, 2019

   Member

   More actions

   Yep! you've found the right files to get started. I'd be happy to help you through the python parts of this if you're interested in getting started! You shouldn't need to deal with git at all as the framework bits handle that. The parts for adding a "language" are just installing $your-language packages and running the executables that get installed.

   There's ~roughly a couple flavors of "languages" right now -- either those which pre-commit will bootstrap an entire environment for you (node / ruby), or where pre-commit will assume some amount of system installation (python, because well, you need python to run pre-commit) or where pre-commit assumes you've installed some sort of system tooling (go / rust / docker / etc.).

   Depending on how the R ecosystem works (I'm not at all familiar with it) you'd pick to either set up a full R runtime or to depend on R already being installed at the system.

   For the apis you have to implement for a language here's what they would do (for instance for R):

   ENVIRONMENT_DIR

   a short string which will be used for the prefix of where packages will be installed. Probably r_env or something like that. (For python for instance, we use py_env and then packages are referenced from py_env/bin/...)

   get_default_version

   probably don't need to implement this for a first pass -- right now this is only implemented by the python language which guesses what interpreter version to try and use for hooks.

   healthy

   probably don't need to implement this for a first pass -- right now this is only implemented by the python language which makes sure that a virtual environment is still dll-linked properly

   install_environment

   this is the tricky part and where the smart bits come in. probably need to do the following things:

   • install an R runtime (optional: you could just depend on R already being installed globally)
   • install the current repository into the ENVIRONMENT_DIR (for python this is pip install . for instance)
   • install additional_dependencies (also optional, but often useful for plugin-like things)

   run_hook

   This is usually the easiest to implement, most of them look the same as the python hook implementation:

   pre-commit/pre_commit/languages/node.py

   Lines 72 to 74 in 1602382

   	def run_hook(hook, file_args):
   	with in_env(hook.prefix, hook.language_version):
   	return helpers.run_xargs(hook, helpers.to_cmd(hook), file_args)

   recent PRs

   Probably the best most-recent PR which added a language is this one: #751

   Then the last bit is adding a few tests for that -- I can help you out with that :)

   👍React with 👍2Reacted by Lorenz Walthert and hcl
3. katrinleinweber

   changed the title [-]How to support for a language?[/-] [+]How to add support for a language?[/+] on Jan 29, 2019
4. lorenzwalthert commented on Feb 16, 2019

   

   lorenzwalthert

   on Feb 16, 2019

   Contributor

   More actions

   Depending on how the R ecosystem works (I'm not at all familiar with it) you'd pick to either set up a full R runtime or to depend on R already being installed at the system.

   I think we can for simplicity depend on the global installation of R.
5. asottile commented on Feb 16, 2019

   

   asottile

   on Feb 16, 2019

   Member

   More actions

   Sounds good, is there a mechanism for local package installation in R?
6. lorenzwalthert commented on Feb 16, 2019

   

   lorenzwalthert

   on Feb 16, 2019

   Contributor

   More actions

   Within the R console (again), you can install.packages("styler") to satisfy all requirements needed. So in the console, when assuming R is installed, you can run

   $ Rscript -e "install.packages('styler', repos='http://cran.rstudio.com')"
   
7. asottile commented on Jun 9, 2019

   

   asottile

   on Jun 9, 2019

   Member

   More actions

   I've decided to clean this up and add it to the docs #1056 -- thanks for the issue it definitely helped me collect my thoughts on this :)
8. asottile

   closed this as completedon Jun 9, 2019
9. katrinleinweber commented on Jun 9, 2019

   

   katrinleinweber

   on Jun 9, 2019

   Author

   More actions

   Awesome, thank you :-)

   🎉React with 🎉1Reacted by anthony sottile
10. scottgigante-immunai commented on Aug 31, 2021

    

    scottgigante-immunai

    on Aug 31, 2021

    More actions

    @katrinleinweber did you ever work out how to write a pre-commit hook for styler? I'm interested in doing the same but don't want to reinvent the wheel
11. lorenzwalthert commented on Aug 31, 2021

    

    lorenzwalthert

    on Aug 31, 2021

    Contributor

    More actions

    @scottgigante-immunai you can use the {styler} hook from https://github.com/lorenzwalthert/precommit, hopefully soon with pre-commit.ci support :D

    🎉React with 🎉1Reacted by Scott Gigante
12. scottgigante-immunai commented on Aug 31, 2021

    

    scottgigante-immunai

    on Aug 31, 2021

    More actions

    Amazing! Thank you!