Challenge 2: Make the Image Job Depend on Tests — Possible Solution
====================================================================

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - run: npm ci
      - run: npm test

  build-image:
    needs: test  # <-- the added dependency
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - run: docker build -t ghcr.io/myorg/myapp:${{ github.sha }} .
      - run: echo "${{ secrets.REGISTRY_TOKEN }}" | docker login ghcr.io -u ${{ github.actor }} --password-stdin
      - run: docker push ghcr.io/myorg/myapp:${{ github.sha }}

WHY THIS WORKS
--------------
- Adding needs: test to the build-image job is the exact mechanism
  Chapter 2 introduced for expressing job dependencies — it tells the
  CI system "do not start this job until the job named test has
  completed successfully."
- Without needs: test, GitHub Actions would treat both jobs as
  INDEPENDENT by default and run them in PARALLEL — meaning build-image
  could start building and pushing an image at the exact same time
  test is still running, or even complete BEFORE test finishes and
  reports a failure. Adding needs: test eliminates this race entirely.
- Critically, needs: doesn't just control ORDERING — per this chapter's
  own point ("a broken build never gets containerized or pushed at
  all"), if the test job FAILS, build-image is automatically SKIPPED
  entirely, not merely delayed until after test finishes. This is what
  actually enforces "only build/push an image for code that passed its
  tests" rather than just "build/push an image sometime after tests
  run, regardless of whether they passed."
- This exactly mirrors this chapter's own worked example (the
  build-and-push job depending on test) — the only change needed here
  was renaming build-and-push to match this challenge's build-image
  job name and adding the same needs: test line that was already
  present in the chapter's reference workflow.