name: Jest Tests

# `pull_request` is deliberately unfiltered.  It was `branches: [master]`, which meant a pull
# request into anything else ran no jest and no webpack build -- so the entire Semantic UI to
# Mantine migration, seventy-five files of it, was reviewed and merged across nine pull requests
# into `feature/custom-theme` without either ever running on a single one of them.  The build
# step matters most of all here: jest and tsc both pass on a named import that does not exist,
# and only webpack rejects it.  The suite did run on the branch afterwards, which is the wrong
# side of the merge to find out.
on:
  push:
    branches: [master, feature/*]
  pull_request:

jobs:
  jest-tests:
    runs-on: ubuntu-latest

    defaults:
      run:
        working-directory: app

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '20.19'
          cache: 'npm'
          cache-dependency-path: app/package-lock.json

      - name: Install dependencies
        run: npm install

      - name: Run Jest tests
        run: CI=true npm test -- --watchAll=false --coverage --coverageReporters=text --coverageReporters=lcov

      # Webpack build catches errors that Jest+Babel don't, e.g. named imports
      # that resolve to `undefined` because the source module doesn't actually
      # export that name (Babel turns these into runtime undefined; webpack
      # rejects them at build time). GitHub Actions sets CI=true in every
      # step's environment by default, which makes react-scripts treat any
      # lint warning as a fatal error — so we override it here. The webpack
      # build still fails on real errors (the goal of this step); only
      # pre-existing lint warnings stop being blocking.
      - name: Build app (catches missing imports etc.)
        env:
          CI: ''
        run: npm run build

      - name: Upload coverage report
        uses: actions/upload-artifact@v4
        with:
          name: coverage-report
          path: app/coverage
          retention-days: 30