Pre-Commit Hooks
devenv
has first-class integration for pre-commit via pre-commit-hooks.nix.
Set up
We recommend a two-step approach for integrating your linters and formatters.
1) Make sure that commits are well-formatted at commit time
devenv.nix
{ inputs, ... }:
{
pre-commit.hooks = {
# lint shell scripts
shellcheck.enable = true;
# execute example shell from Markdown files
mdsh.enable = true;
# format Python code
black.enable = true;
# override a package with a different version
ormolu.enable = true;
ormolu.package = pkgs.haskellPackages.ormolu;
# some hooks have more than one package, like clippy:
clippy.enable = true;
clippy.packageOverrides.cargo = pkgs.cargo;
clippy.packageOverrides.clippy = tools.clippy;
# some hooks provide settings
clippy.settings.allFeatures = true;
};
}
In action:
If you commit a Python or Markdown file or a script, these hooks will run at commit time.
2) Verify formatting in CI
Run devenv test
.
See the list of all available hooks.
Managing the .pre-commit-config.yaml
file
The .pre-commit-config.yaml
file is a symlink to an autogenerated file in your devenv
Nix store.
It is not necessary to commit this file to your repository and it can safely be ignored.
This file name will be added to your .gitignore
file by default when you run devenv init
.
Adding custom hooks
If you'd like to define your own hook you can do:
devenv.nix
{
pre-commit.hooks.unit-tests = {
enable = true;
# The name of the hook (appears on the report table):
name = "Unit tests";
# The command to execute (mandatory):
entry = "make check";
# The pattern of files to run on (default: "" (all))
# see also https://pre-commit.com/#hooks-files
files = "\\.(c|h)$";
# List of file types to run on (default: [ "file" ] (all files))
# see also https://pre-commit.com/#filtering-files-with-types
# You probably only need to specify one of `files` or `types`:
types = [ "text" "c" ];
# Exclude files that were matched by these patterns (default: [ ] (none)):
excludes = [ "irrelevant\\.c" ];
# The language of the hook - tells pre-commit
# how to install the hook (default: "system")
# see also https://pre-commit.com/#supported-languages
language = "system";
# Set this to false to not pass the changed files
# to the command (default: true):
pass_filenames = false;
};
}