name: NPM Package

on:
  push:
    branches: [ master ]

jobs:
  publish-npm:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - uses: actions/setup-node@v1
        with:
          node-version: 14
          registry-url: https://registry.npmjs.org/
      - name: Cache Node.js modules
        uses: actions/cache@v2
        with:
          # npm cache files are stored in `~/.npm` on Linux/macOS
          path: ~/.npm
          key: ${{ runner.OS }}-node-${{ hashFiles('**/package-lock.json') }}
          restore-keys: |
            ${{ runner.OS }}-node-
            ${{ runner.OS }}-
      - run: npm install
      - name: Tag & publish
        env:
          NODE_AUTH_TOKEN: ${{secrets.npm_token}}
        run: |
          OLD_VERSION=$(npm show wavesurfer.js version)
          NEW_VERSION=$(node -p 'require("./package.json").version')
          if [ $NEW_VERSION != $OLD_VERSION ]; then
            git tag "$NEW_VERSION"
            git push --tags
            npm publish
          fi