name: Build check

# Proves the split Dockerfile actually builds (repo-split Stage 7b) -- NOT a
# live boot+healthz check. content.register() fetches the IndexNow key from
# backend at import time with no retry (documented Stage 4 behavior,
# unchanged here); without a real, reachable backend this process crashes
# immediately on import, by design -- so a standalone boot check would either
# be fake (skip the real import path) or require checking out and booting
# thermograph-backend too. That's the real fix (a genuine cross-repo
# contract-test job, same pattern the original repo-split plan already
# scoped for the /cell + ETag contract), not yet built -- flagged as a real
# gap, not silently skipped. Full pytest-suite migration is separate,
# deferred follow-up work too, same category as thermograph-copy's deferred
# vendoring.
#
# workflow_call added alongside `dev` on both push/pull_request filters
# (dev-branch flow, mirroring the monorepo's build.yml): pr-build.yml (PRs
# into dev) and deploy-dev.yml (pushes to dev) both `uses:` this file as
# their shared build gate, same build-only behavior either way -- direct
# push/PR-to-main triggers are unchanged.

on:
  push:
    branches: [main, dev]
  pull_request:
    branches: [main, dev]
  workflow_call: {}

jobs:
  build:
    runs-on: docker
    steps:
      - uses: actions/checkout@v4

      - name: Install Docker CLI
        run: |
          apt-get update -qq
          apt-get install -y -qq docker.io

      - name: Build
        run: docker build -t thermograph-frontend:ci .

      # Run the hermetic unit tier INSIDE the image we just built (it ships
      # tests/ + all runtime deps via COPY . /app/): fixture-backed rendering
      # tests, no backend, no network. The integration tier
      # (tests/integration/, needs a live backend container) stays a local
      # `make`/scripts concern -- see scripts/backend-for-tests.sh.
      # requirements-dev.txt only layers pytest on top, so the install is tiny.
      # -u 0: the image's default user can't write to site-packages.
      # unset THERMOGRAPH_BASE: the image bakes the prod root-mount; the tests
      # expect the app default (/thermograph), same rationale as the backend.
      - name: Run unit tests in the built image
        run: |
          docker run --rm -u 0 thermograph-frontend:ci \
            sh -c "unset THERMOGRAPH_BASE; pip install -q --no-cache-dir pytest==8.4.1 && python -m pytest tests/unit -q"