This GitHub Action automatically formats code using Prettier when a pull request is opened or updated. It then commits and pushes the formatted code back to the same PR branch, ensuring consistent code style across contributions without manual intervention.

auto-commit.yml

name: 'Auto Commit Prettier'

on:
  pull_request:
    branches: ['main']

jobs:
  auto-commit:
    name: 'Auto Commit'
    runs-on: ['ubuntu-latest']
    env:
      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
    steps:
      - name: 'checkout'
        uses: actions/checkout@v4
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
          ref: ${{ github.event.pull_request.head.ref }}

      - name: 'format'
        run: npm_config_yes=true npx prettier@latest --write .

      - name: 'setup git config'
        run: |
          git config --global user.name "Acme Bot"
          git config --global user.email "username@users.noreply.github.com"

      - name: 'commit'
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          git add . --all
          git commit --all --message "chore: prettier auto commit"
          git push