✨ Lint Action

• Shows linting errors on GitHub commits and PRs
• Allows auto-fixing issues
• Supports many linters and formatters

Note: The behavior of actions like this one is currently limited in the context of forks. See Limitations.

Screenshots

• Checks on pull requests:

  

• Commit annotations:

  

Supported tools

• CSS:
  • stylelint
• Go:
  • gofmt
  • golint
• JavaScript:
  • ESLint
  • Prettier
  • XO
• PHP:
  • PHP_CodeSniffer
• Python:
  • Black
  • Flake8
  • Mypy
• Ruby:
  • RuboCop
• Swift:
  • swift-format (official)
  • SwiftFormat (by Nick Lockwood)
  • SwiftLint

Usage

Create a new GitHub Actions workflow in your project, e.g. at .github/workflows/lint.yml. The content of the file should be in the following format:

name: Lint

on: push

jobs:
  run-linters:
    name: Run linters
    runs-on: ubuntu-latest

    steps:
      - name: Check out Git repository
        uses: actions/checkout@v2

      # Install your linters here

      - name: Run linters
        uses: wearerequired/lint-action@v1
        with:
          github_token: ${{ secrets.github_token }}
          # Enable your linters here

Examples

All linters are disabled by default. To enable a linter, simply set the option with its name to true, e.g. eslint: true.

The action doesn't install the linters for you; you are responsible for installing them in your CI environment.

JavaScript example (ESLint and Prettier)

name: Lint

on: push

jobs:
  run-linters:
    name: Run linters
    runs-on: ubuntu-latest

    steps:
      - name: Check out Git repository
        uses: actions/checkout@v2

      - name: Set up Node.js
        uses: actions/setup-node@v1
        with:
          node-version: 12

      # ESLint and Prettier must be in `package.json`
      - name: Install Node.js dependencies
        run: npm install

      - name: Run linters
        uses: wearerequired/lint-action@v1
        with:
          github_token: ${{ secrets.github_token }}
          # Enable linters
          eslint: true
          prettier: true

PHP example (PHP_CodeSniffer)

name: Lint

on: push

jobs:
  run-linters:
    name: Run linters
    runs-on: ubuntu-latest

    steps:
      - name: Check out Git repository
        uses: actions/checkout@v2

      - name: Set up PHP
        uses: shivammathur/setup-php@v2
        with:
          php-version: "7.4"
          coverage: none
          tools: phpcs

      - name: Run linters
        uses: wearerequired/lint-action@v1
        with:
          github_token: ${{ secrets.github_token }}
          # Enable linters
          php_codesniffer: true
          # Optional: Ignore warnings
          php_codesniffer_args: "-n"

If you prefer to use Composer you can also use this:

name: Lint

on: push

jobs:
  run-linters:
    name: Run linters
    runs-on: ubuntu-latest

    steps:
      - name: Check out Git repository
        uses: actions/checkout@v2

      - name: Set up PHP
        uses: shivammathur/setup-php@v2
        with:
          php-version: "7.4"
          coverage: none
          tools: composer

      - name: Install PHP dependencies
        run: |
          composer install --prefer-dist --no-suggest --no-progress --no-ansi --no-interaction
          echo "::add-path::vendor/bin"

      - name: Run linters
        uses: wearerequired/lint-action@v1
        with:
          github_token: ${{ secrets.github_token }}
          # Enable linters
          php_codesniffer: true

Python example (Flake8 and Black)

name: Lint

on: push

jobs:
  run-linters:
    name: Run linters
    runs-on: ubuntu-latest

    steps:
      - name: Check out Git repository
        uses: actions/checkout@v2

      - name: Set up Python
        uses: actions/setup-python@v1
        with:
          python-version: 3.8

      - name: Install Python dependencies
        run: pip install black flake8

      - name: Run linters
        uses: wearerequired/lint-action@v1
        with:
          github_token: ${{ secrets.github_token }}
          # Enable linters
          black: true
          flake8: true

Configuration

Linter-specific options

[linter] can be one of black, eslint, flake8, gofmt, golint, mypy, php_codesniffer, prettier, rubocop, stylelint, swift_format_official, swift_format_lockwood, swiftlint and xo:

• [linter]: Enables the linter in your repository. Default: false
• [linter]_args: Additional arguments to pass to the linter. Example: eslint_args: "--max-warnings 0" if ESLint checks should fail even if there are no errors and only warnings. Default: ""
• [linter]_dir: Directory where the linting command should be run. Example: eslint_dir: server/ if ESLint is installed in the server subdirectory. Default: Repository root
• [linter]_extensions: Extensions of files to check with the linter. Example: eslint_extensions: js,ts to lint JavaScript and TypeScript files with ESLint. Default: Varies by linter, see action.yml
• [linter]_command_prefix: Command prefix to be run before the linter command. Default: "".

General options

• auto_fix: Whether linters should try to fix code style issues automatically. If some issues can be fixed, the action will commit and push the changes to the corresponding branch. Default: false

  

• git_name: Username for auto-fix commits. Default: "Lint Action"

• git_email: Email address for auto-fix commits. Default: "lint-action@samuelmeuli.com"

• commit_message: Template for auto-fix commit messages. The ${linter} variable can be used to insert the name of the linter. Default: "Fix code style issues with ${linter}"

• check_name: Template for the name of the check run. Use this to ensure unique names when the action is used more than once in a workflow. The ${linter} and ${dir} variables can be used to insert the name and directory of the linter. Default: "${linter}"

Linter support

Some options are not be available for specific linters:

Linter	auto-fixing	extensions
black	✅	✅
eslint	✅	✅
flake8	❌	✅
gofmt	✅	❌ (go)
golint	❌	❌ (go)
mypy	✅	✅
php_codesniffer	❌	✅
prettier	✅	✅
rubocop	✅	❌ (rb)
stylelint	✅	✅
swift_format_official	✅	✅
swift_format_lockwood	✅	❌ (swift)
swiftlint	✅	❌ (swift)
xo	✅	✅

Limitations

There are currently some limitations as to how this action (or any other action) can be used in the context of pull_request events from forks:

• The action doesn't have permission to push auto-fix changes to the fork. This is because the pull_request event runs on the upstream repo, where the github_token is lacking permissions for the fork. Source
• The action doesn't have permission to create annotations for commits on forks and can therefore not display linting errors. Source 1, source 2

For details and comments, please refer to #13.

Related

• Electron Builder Action – GitHub Action for building and releasing Electron apps
• Maven Publish Action – GitHub Action for automatically publishing Maven packages