Day 2: Automated Testing in CI — CI/CD in 5 Days

Today's Objective

By the end of this lesson, you will understand the core concepts of Automated Testing in CI — CI/CD in 5 Days and be able to apply them in a real project.

yaml

# .github/workflows/test.yml
name: Test

on: [push, pull_request]

jobs:
  test:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4

      - uses: actions/setup-node@v4
        with:
          node-version: '20'
          cache: 'npm'

      - run: npm ci

      - name: Run tests with coverage
        run: npm test -- --coverage --coverageReporters=lcov

      - name: Upload coverage to Codecov
        uses: codecov/codecov-action@v4
        with:
          token: ${{ secrets.CODECOV_TOKEN }}
          files: ./coverage/lcov.info
          fail_ci_if_error: true

      - name: Check coverage threshold
        run: |
          COVERAGE=$(node -e "
            const c = require('./coverage/coverage-summary.json');
            console.log(c.total.lines.pct);
          ")
          echo "Line coverage: $COVERAGE%"
          node -e "if ($COVERAGE < 80) { console.error('Coverage below 80%'); process.exit(1); }"

json

{
  "scripts": {
    "test": "jest --passWithNoTests"
  },
  "jest": {
    "coverageThreshold": {
      "global": {
        "lines": 80,
        "functions": 80,
        "branches": 70
      }
    }
  }
}