linter.yml

name: ESLint

on:
  pull_request:
    branches: [master]

jobs:
  build:
    name: Lint updated JavaScript files with ESLint

    runs-on: ubuntu-20.04

    steps:
      - name: Checkout code
        uses: actions/checkout@v3
        with:
          fetch-depth: 0
          ref: ${{ github.event.pull_request.head.sha }}

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

      - name: Get changed files
        id: getfile
        run: |
          CHANGED_FILES="$(git diff --name-only ${{ github.event.pull_request.base.sha }}..${{ github.event.pull_request.head.sha }} | xargs)"
          export CHANGED_FILES  # the export command will fail if the inner shell expansion failed
          echo "files=$CHANGED_FILES" >> $GITHUB_OUTPUT

      - name: Install ESLint
        run: npm install eslint

      - name: Lint changed files using ESLint
        run: |
          for i in ${{ steps.getfile.outputs.files }}
          do
            if [[ "$i" == "D" ]]
            then
              ignore=1
            elif [[ ( "$i" == "M" ) || ( "$i" == "A" ) || ( "$i" == "R" ) || ( "$i" == "C" ) || ( "$i" == "U" ) ]]
            then
              ignore=0
            fi
            echo "file $i $ignore"
            if [[ "$i" == *".js" && $ignore == 0 ]]
            then
              echo "linting $i"
              npx eslint $i
            fi
          done