quality-assurance（品质保证）

Quality Assurance

Ensure quality throughout the spec-driven development process with validation techniques, quality gates, and testing strategies.

When to Use This Skill

Use quality assurance practices when:

• Completing any spec phase (requirements, design, tasks)
• Transitioning between phases
• Implementing features from specs
• Reviewing completed work
• Establishing team quality standards

Core Principles

1. Requirements-Driven Testing: Every test traces to a requirement
2. Phase-Appropriate Validation: Different techniques for each phase
3. Continuous Quality: Checks throughout development
4. Automated Where Possible: Reduce manual effort
5. Fast Feedback: Catch issues early

Phase-Specific Validation

Requirements Phase Validation

Quality Checklist:

• All user stories have acceptance criteria
• Requirements are unambiguous and specific
• Each requirement can be validated/tested
• EARS format used consistently
• Requirements link to business objectives
• No conflicting requirements

Review Process:

1. Self Review: Author checks completeness
2. Stakeholder Review: Business validates requirements
3. Technical Review: Team assesses feasibility
4. Approval: Formal sign-off before design

Validation Techniques:

• Scenario Walkthroughs: Step through user journeys
• Edge Case Analysis: Identify boundary conditions
• Conflict Detection: Check for contradictions
• Completeness Analysis: Ensure all needs covered

Design Phase Validation

Quality Checklist:

• Design addresses all requirements
• Scalability considerations documented
• Maintainability assessed
• Security addressed
• Performance requirements considered
• External integrations defined

Review Process:

1. Architecture Review: Senior team validates design
2. Security Review: Security implications assessed
3. Performance Review: Performance characteristics evaluated
4. Integration Review: External dependencies validated

Validation Techniques:

• Design Walkthroughs: Step through system interactions
• Threat Modeling: Identify security vulnerabilities
• Performance Modeling: Estimate system performance
• Dependency Analysis: Map external requirements

Tasks Phase Validation

Quality Checklist:

• Each task has clear deliverables
• Task sequence is logical
• All design elements covered
• Each task can be validated
• Tasks appropriately sized (2-4 hours)
• Dependencies clearly defined

Review Process:

1. Completeness Review: All design elements have tasks
2. Sequencing Review: Task order is logical
3. Scope Review: Tasks are appropriately sized
4. Dependency Review: Dependencies clear

Quality Gates

Requirements Phase Exit Criteria

• All user stories follow proper format
• Acceptance criteria use EARS format
• Requirements are testable and measurable
• No conflicting requirements
• Stakeholders have approved
• Edge cases documented

Design Phase Exit Criteria

• Architecture addresses all requirements
• Non-functional requirements addressed
• External dependencies identified
• Data models clearly defined
• Error handling documented
• Security considerations addressed
• Technical review completed

Tasks Phase Exit Criteria

• All design elements have tasks
• Tasks properly sequenced
• Each task is actionable
• Requirements references included
• Test approach defined
• Task breakdown reviewed

Task-Level Quality Gates

Before Starting:

• Task requirements understood
• Test strategy defined
• Dependencies available
• Environment ready

During Implementation:

• Code follows standards
• Tests written alongside code
• Coverage meets thresholds (80%+)
• No critical vulnerabilities

Before Marking Complete:

• All tests pass
• Code review completed
• Documentation updated
• Requirements validated

Testing Strategies

Test Pyramid

       /\
      /  \     E2E Tests (10%)
     /____\    Integration Tests (20%)
    /      \
   /________\   Unit Tests (70%)

Unit Testing

• Fast execution (< 1 second per test)
• Test individual functions/classes
• Mock external dependencies
• Target 80%+ coverage

Integration Testing

• Test component interactions
• Use real dependencies where practical
• Validate API contracts
• Test critical workflows

End-to-End Testing

• Test complete user journeys
• Production-like environment
• Focus on critical business flows
• Minimal but comprehensive

Test-Driven Development

For each task:

1. Write tests first based on acceptance criteria
2. Run tests - verify they fail (red)
3. Write code - minimal to pass tests (green)
4. Refactor - improve while keeping tests green
5. Validate - ensure requirements satisfied

Quality Metrics

Code Quality

• Line Coverage: % of code lines executed
• Branch Coverage: % of code branches tested
• Cyclomatic Complexity: Code complexity
• Technical Debt: Accumulated issues

Testing Effectiveness

• Test Pass Rate: % of tests passing
• Execution Time: Time to run tests
• Defect Detection Rate: Bugs found by tests vs production
• Test Maintenance: Time spent maintaining tests

Common Quality Issues

Flaky Tests

Symptoms: Tests pass/fail inconsistently Solutions:

• Identify timing dependencies
• Use proper wait conditions
• Isolate test data
• Fix race conditions

Slow Test Suites

Symptoms: Tests take too long Solutions:

• Parallelize execution
• Optimize database operations
• Use test doubles for external services
• Profile and optimize slow tests

Low Coverage

Symptoms: Insufficient code coverage Solutions:

• Add tests for uncovered paths
• Focus on critical business logic
• Use mutation testing
• Set coverage gates in CI

Test Maintenance Burden

Symptoms: Tests require frequent updates Solutions:

• Improve test design
• Use page object patterns for UI
• Reduce coupling to implementation
• Regular test refactoring

Validation Checklists

Requirements Validation

## Requirements Review

**Completeness:**
- [ ] All user roles addressed
- [ ] Happy path scenarios covered
- [ ] Edge cases documented
- [ ] Error cases handled
- [ ] Business rules captured

**Clarity:**
- [ ] Precise language used
- [ ] No ambiguous terms
- [ ] Technical jargon avoided
- [ ] Behaviors are specific

**Testability:**
- [ ] Each requirement verifiable
- [ ] Success criteria observable
- [ ] Inputs/outputs specified

Design Validation

## Design Review

**Architecture:**
- [ ] Requirements addressed
- [ ] Components well-defined
- [ ] Interfaces specified
- [ ] Data flow documented

**Quality Attributes:**
- [ ] Performance considered
- [ ] Security addressed
- [ ] Scalability planned
- [ ] Maintainability assessed

**Risks:**
- [ ] Single points of failure identified
- [ ] Bottlenecks documented
- [ ] Mitigations planned

Implementation Validation

## Implementation Review

**Code Quality:**
- [ ] Follows standards
- [ ] Well-documented
- [ ] Tests included
- [ ] No security issues

**Requirements:**
- [ ] All criteria met
- [ ] Edge cases handled
- [ ] Error handling complete

**Integration:**
- [ ] Works with existing code
- [ ] APIs functioning
- [ ] Performance acceptable

Best Practices

Testing Best Practices

1. Write tests first when possible
2. Each test verifies one thing
3. Use descriptive test names
4. Maintain test independence
5. Keep tests up-to-date

Quality Assurance Best Practices

1. Find issues early (shift left)
2. Automate everything possible
3. Use metrics to drive improvements
4. Make quality everyone's responsibility
5. Continuous learning and improvement

Process Integration

1. Link tests to requirements
2. Provide quick feedback
3. Focus testing on high-risk areas
4. Keep documentation current
5. Integrate tools with workflow

Quick Reference

Phase Transition Questions:

• Requirements → Design: "Does design address all requirements?"
• Design → Tasks: "Do tasks cover all design elements?"
• Tasks → Implementation: "Does code satisfy task specifications?"

Quality Gate Questions:

• "Is this testable and measurable?"
• "Have we considered what could go wrong?"
• "Would another developer understand this?"
• "Does this meet our standards?"