Action-py-black-formatter GitHub Action

This is a fork of rickstaa/action-black so that we can backport an older version of black working.

Quickstart

In it's simplest form this action can be used to check/format your code using the black formatter.

name: black-action
on: [push, pull_request]
jobs:
  linter_name:
    name: runner / black formatter
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - uses: datadog/action-py-black-formatter@v2.1
        with:
          check_mode: "true"

Inputs

additional_args

optional: Black additional input arguments. Default "".

only_changed_files

optional: When enabled if you only want to check changed files instead of all files. Recommended for large repositories. Default "false".

main_branch

optional: Default main branch to compare if only_changed_files mode enabled. Default "main".

quiet_mode

optional: (--quiet) Don't emit non-error messages to stderr. Errors are still emitted; silence those with 2>/dev/null. Default "false".

check_mode

optional: (--check) Don't write the files back, just return the status. Return code 0 means nothing would change. Return code 1 means some files would be reformatted. Return code 123 means there was an internal error. Default "false"

print_diff_mode

optional: (--diff) Don't write the files back, just output a diff for each file on stdout. Default "false".

fail_on_error

optional: Exit code when black formatting errors are found [true, false]. Default "true".

Outputs

is_formatted

Boolean specifying whether any files were formatted using the black formatter.

Advanced use cases

Annotate changes

This action can be combined with reviewdog/action-suggester also to annotate any possible changes (uses git diff).

name: black-action
on: [push, pull_request]
jobs:
  linter_name:
    name: runner / black
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - name: Check files using the black formatter
        uses: datadog/action-py-black-formatter@v2.1
        id: action_black
      - name: Annotate diff changes using reviewdog
        if: steps.action_black.outputs.is_formatted == 'true'
        uses: reviewdog/action-suggester@v1
        with:
          tool_name: blackfmt

Commit changes or create a pull request

This action can be combined with peter-evans/create-pull-request to also apply the annotated changes to the repository.

name: black-action
on: [push, pull_request]
jobs:
  linter_name:
    name: runner / black
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - name: Check files using the black formatter
        uses: datadog/action-py-black-formatter@v2.1
        id: action_black
      - name: Create Pull Request
        if: steps.action_black.outputs.is_formatted == 'true'
        uses: peter-evans/create-pull-request@v3
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
          title: "Format Python code with psf/black push"
          commit-message: ":art: Format Python code with psf/black"
          body: |
            There appear to be some python formatting errors in ${{ github.sha }}. This pull request
            uses the [psf/black](https://github.com/psf/black) formatter to fix these issues.
          base: ${{ github.head_ref }} # Creates pull request onto pull request or commit branch
          branch: actions/black