pre-commit/action

a GitHub action to run pre-commit

using this action

To use this action, make a file .github/workflows/pre-commit.yml. Here's a template to get started:

name: pre-commit

on:
  pull_request:
  push:
    branches: [master]

jobs:
  pre-commit:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v2
    - uses: actions/setup-python@v2
    - uses: pre-commit/action@v2.0.0

This does a few things:

• clones the code
• installs python
• sets up the pre-commit cache

using this action with custom invocations

By default, this action runs all the hooks against all the files. extra_args lets users specify a single hook id and/or options to pass to pre-commit run.

Here's a sample step configuration that only runs the flake8 hook against all the files (use the template above except for the pre-commit action):

    - uses: pre-commit/action@v2.0.0
      with:
        extra_args: flake8 --all-files

using this action in private repositories

this action also provides an additional behaviour when used in private repositories. when configured with a github token, the action will push back fixes to the pull request branch.

using the template above, you'll make two replacements for individual actions:

first is the checkout step, which needs to use unlimited fetch depth for pushing

    - uses: actions/checkout@v2
      with:
        fetch-depth: 0

next is passing the token to the pre-commit action

    - uses: pre-commit/action@v2.0.0
      with:
        token: ${{ secrets.GITHUB_TOKEN }}

note that secrets.GITHUB_TOKEN is automatically provisioned and will not require any special configuration.

using this action to push to public repository pull requests

This action can push to pull requests in public repositories using the pull_request_target. Remember that code in a public PR may be untrusted.

name: pre-commit

on:

  pull_request_target:

jobs:
  pre-commit:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
        with:
          repository: ${{ github.event.pull_request.head.repo.full_name }}
          # Use sha instead of ref because pre-commit attempts to checkout a branch with the same name
          # https://github.com/pre-commit/action/blob/20242c769824ac7e54269ee9242da5bfae19c1c8/index.js#L77
          ref: ${{ github.event.pull_request.head.sha }}
          fetch-depth: 0
      - uses: actions/setup-python@v2
      - uses: pre-commit/action@v2.0.0
        with:
          token: ${{ secrets.GITHUB_TOKEN }}