Shift-Left Testing

<default_to_action> When implementing early testing practices:

1. VALIDATE requirements before coding (testability, BDD scenarios)
2. WRITE tests before implementation (TDD)
3. AUTOMATE in CI pipeline (every commit triggers tests)
4. FIX defects immediately - never let them accumulate

Quick Shift-Left Levels:

• Level 1: Unit tests with each PR (developer responsibility)
• Level 2: TDD practice (tests before code)
• Level 3: BDD/Example mapping in refinement (requirements testing)
• Level 4: Risk analysis in design (architecture testing) </default_to_action>

Quick Reference Card

When to Use

• Reducing cost of defects
• Implementing CI/CD pipelines
• Starting TDD practice
• Improving requirements quality

Shift-Left Levels

Level	Practice	When
1	Unit tests in PR	Before merge
2	TDD	Before implementation
3	BDD/Example Mapping	During refinement
4	Risk Analysis	During design

---

Level 1: Tests in Every PR

# CI pipeline - tests run on every commit
name: CI
on: [push, pull_request]
jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - run: npm ci
      - run: npm run test:unit
      - run: npm run test:integration
      - run: npm run lint

  quality-gate:
    needs: test
    steps:
      - name: Coverage Check
        run: npx coverage-check --min 80
      - name: No New Warnings
        run: npm run lint -- --max-warnings 0

---

Agent-Assisted Shift-Left

// Validate requirements testability
await Task("Requirements Validation", {
  requirements: userStories,
  check: ['INVEST-criteria', 'testability', 'ambiguity'],
  generateBDD: true
}, "qe-requirements-validator");

// Generate tests from requirements
await Task("Generate Tests", {
  source: 'requirements',
  types: ['unit', 'integration', 'e2e'],
  coverage: 'comprehensive'
}, "qe-test-generator");