Verifying that npm install installed from cache

Question

How can I verify that npm install installed modules from the npm cache, from inside a Github action step?

Answer 1

There won't be an npm cache by default. The boxes it spins up will be new every time. You can configure one using actions/cache. It would look something like:

jobs:
  build:
    name: Build
    runs-on: ubuntu-latest
    steps:
      - name: Clone project
        uses: actions/checkout@v3
      - name: Install node
        uses: actions/setup-node@v3
        with:
          node-version: '18'
      - name: Cache dependencies
        id: cache
        uses: actions/cache@v3
        with:
          path: ./node_modules
          key: modules-${{ hashFiles('package-lock.json') }}
      - name: Install dependencies
        if: steps.cache.outputs.cache-hit != 'true'
        run: npm ci
      - name: Build
        run: npm run build

To verify it, you can run the build once, then run the same build again. The subsequent run should be faster. You can also verify in the output that the "Install dependencies" (or whatever name you give it) is skipped.

Note: the display above will be what you see with explicitly defined steps like the config above. More complex setups might bundle all of this in an action, but you would still