Github Actions

pre-commit hooks

What is a Pre-Commit Hook?

Pre-commit hooks are a simple way to check your code for any issues before committing your code to Github. It could be something as simple as removing extra spaces from the end of a file to verifying that the code you want to commit is valid Python or does not contain any secrets or access tokens. Pre-Commit Hooks can be written in a number of languages including Python, Ruby, and Rust but we're going to focus on Python for this demo.

Setup

With pip

pip install pre-commit or pip3 install pre-commit

With conda

conda install -c conda-forge pre-commit

Pre-Written Hooks

One of the most useful aspects is the ability to easily use pre-written hooks in your own repo.

Adding Pre-Commit Hooks to your Repo

To add, you create a file called .pre-commit-config.yaml and save it in the root of your repo.

Example:

repos:

• repo: https://github.com/path-to-repo-with-hook # url to repo containing hook.
  rev: v2.3.0
  hooks: # list of hooks to use.
  • id: hook-i-want.
    description: Looks at file size, max set to 250kb.
    args: [--maxkb=250].

Examples of Useful Pre-Commit Hooks

Examples and notes in .pre-commit-config.yaml

Custom Pre-Commit-Hooks

Using Hooks

Add the .pre-commit-config.yaml to the root of your directory.
Create a requirements.txt file and add pre-commit.
run pre-commit install from the root of your repo on the command line to add the hooks to your .git/.

More Resources

More Information on Hooks

More Pre-Built Pre-Commit Hooks