DEV Community

Cover image for Amazing `pre-commit` and How To Use It
Vaiolabs profile image Alex M. Schapelle
Alex M. Schapelle for Vaiolabs

Posted on

Amazing `pre-commit` and How To Use It

#git #hooks #gitlab #python

Welcome back dear reader. My name is Alex M. Schapelle,AKA Silent-Mobius, your dedicated container whisperer. On today's escapade, we'll dwell on case, where we need to have client and server rules on our code version control and how to solve it.

Essentially, despite us being mon-keig with great potential, we still find ourselves handling great deal of work manually. In special cases of code control, we need, someone or something to check existing or possible errors. As it happened to be, there git version control, was developed to have hooks, to automate those code checks, yet those hooks are still are a code, that need to be written and maintained... Enter pre-commit

pre-commit is a framework that manages and maintains multi-language pre-commit hooks. It helps catch common issues—like syntax errors, style violations, and forgotten debug statements—before you commit code. This tutorial will guide you through installing, configuring, and using pre-commit in your projects.

Introduction

pre-commit automates the running of scripts (hooks) before a commit is finalized, ensuring that code adheres to your standards. By catching errors early, it can save you time and maintain code quality throughout your project lifecycle.

Installation

Using pip

Install pre-commit via pipx:

sudo apt-get update && sudo apt-get install python3-pip3 pipx -y 
pipx install pre-commit
Enter fullscreen mode Exit fullscreen mode

Verify Installation

Confirm the installation with:

pre-commit --version
Enter fullscreen mode Exit fullscreen mode

Configuration

pre-commit uses a configuration file named .pre-commit-config.yaml in the root of your project, notice the . dot in the name, which is required. This file specifies which repositories of hooks to use and which hooks to run.

Example Configuration

Create a file named .pre-commit-config.yaml with the following content:

repos:
  - repo: https://github.com/pre-commit/pre-commit-hooks
    rev: v4.4.0  # Use the desired revision
    hooks:
      - id: trailing-whitespace
      - id: end-of-file-fixer
  - repo: https://github.com/psf/black
    rev: 23.1.0  # Use the appropriate version for your project
    hooks:
      - id: black
  - repo: https://github.com/pycqa/flake8
    rev: 6.0.0
    hooks:
      - id: flake8
Enter fullscreen mode Exit fullscreen mode

The example above:

  • Uses a set of common hooks from pre-commit-hooks for formatting fixes.
  • Integrates Black for code formatting.
  • Integrates Flake8 for code linting.

Usage

Installing Hooks

To set up the hooks defined in your configuration file, run:

pre-commit install
Enter fullscreen mode Exit fullscreen mode

This command configures your Git repository to run the pre-commit hooks automatically on git commit.

Running Hooks Manually

You can run all configured hooks on all files at any time with:

pre-commit run --all-files
Enter fullscreen mode Exit fullscreen mode

Bypassing Hooks

If necessary, you can bypass pre-commit hooks using the --no-verify flag when committing:

git commit -m "Your commit message" --no-verify
Enter fullscreen mode Exit fullscreen mode

[!] Note: Bypassing hooks should be done sparingly, as it may allow code with issues to be committed.

Advanced Topics

Updating Hooks

Keep your hooks up-to-date by running:

pre-commit autoupdate
Enter fullscreen mode Exit fullscreen mode

After updating, review and commit the changes in .pre-commit-config.yaml.

Customizing Hooks

Some hooks allow for custom arguments. For example, configuring isort to work with Black:

repos:
  - repo: https://github.com/pre-commit/mirrors-isort
    rev: v5.10.1
    hooks:
      - id: isort
        args: ['--profile', 'black']
Enter fullscreen mode Exit fullscreen mode

Using Pre-commit in CI/CD

To integrate pre-commit in your CI/CD pipeline, run:

pre-commit run --all-files --verbose
Enter fullscreen mode Exit fullscreen mode

This ensures that all code is checked for quality standards as part of your automated builds.

Troubleshooting

  • Hooks Not Running: Verify that pre-commit is installed and that the .pre-commit-config.yaml file is located in the root directory of your repository.
  • Hook Failures: Review the error messages provided by the hook. Often, they will indicate how to fix issues such as formatting or linting errors.
  • Skipping Hooks: Remember that while you can bypass hooks with --no-verify, doing so may allow problematic code to be committed.

Resources

Conclusion

Hope that you found this segment some what informative and gained the skill to elevate yourselves, remember that pre-commit is a powerful tool for maintaining code quality. Start with the basic setup and explore what suits your project based on documentation and other resources.
Hope that this article was committed useful information to you. Like, comment and share, and also : Do Try To Have Fun.

Thank you

Top comments (1)

Collapse
 
di3z1e profile image
David Azani • • Edited

Looks interesting might check it out in the future 😃