shift-left-testing

# 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 ```yaml # 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 ```typescript // 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"); // Smart test selection for changes await Task("Select Regression Tests", { changedFiles: prFiles, algorithm: 'risk-based', targetReduction: 0.7 // 70% time savings }, "qe-regression-risk-analyzer"); ``` --- ## Agent Coordination Hints ### Memory Namespace ``` aqe/shift-left/ ├── requirements/* - Validated requirements ├── generated-tests/* - Auto-generated tests ├── coverage-targets/* - Coverage goals by component └── pipeline-results/* - CI/CD test history ``` ### Fleet Coordination ```typescript const shiftLeftFleet = await FleetManager.coordinate({ strategy: 'shift-left', agents: [ 'qe-requirements-validator', // Level 3-4 'qe-test-generator', // Level 2 'qe-regression-risk-analyzer' // Smart selection ], topology: 'sequential' }); ``` --- ## Related Skills - [tdd-london-chicago](../tdd-london-chicago/) - TDD practices - [holistic-testing-pact](../holistic-testing-pact/) - Proactive testing - [cicd-pipeline-qe-orchestrator](../cicd-pipeline-qe-orchestrator/) - Pipeline integration - [shift-right-testing](../shift-right-testing/) - Production feedback --- ## Remember **With Agents:** Agents validate requirements testability, generate tests from specs, and select optimal regression suites. Use agents to implement shift-left practices consistently. ## Skill Composition - **TDD practice** → Use `/tdd-london-chicago` for specific TDD guidance - **Generate tests** → Use `/qe-test-generation` for AI-powered test generation - **CI/CD quality** → Use `/cicd-pipeline-qe-orchestrator` for pipeline setup ## Gotchas - "Shift left" doesn't mean "only test left" — production monitoring (shift right) is still needed - Agent generates tests before understanding requirements — tests for wrong behavior are worse than no tests - CI pipeline tests that take >10 minutes kill the feedback loop — keep commit-stage tests under 5 minutes - TDD discipline degrades when agent writes test+code simultaneously — enforce Red phase separation - Shifting left without lightweight environments just shifts the bottleneck — fix environments first