Testing Strategy Enforcement Skill

Purpose

This skill ensures that all code changes in Black Trigram maintain exceptional test coverage, proper testing strategies across unit/E2E layers, and validate performance and accessibility standards throughout the codebase.

When to Apply

Automatically trigger this skill when:

• Adding new features or components
• Modifying existing game logic or systems
• Implementing UI components (React or Three.js)
• Working with combat, animation, or vital point systems
• Creating or updating state management logic
• Adding performance-critical code
• Implementing accessibility features
• Refactoring existing code
• Reviewing pull requests with code changes

Core Principles

1. Test Coverage Requirements

ALWAYS maintain these coverage thresholds:

✅ Overall Coverage Targets

// Partial excerpt from vitest.config.ts - Coverage configuration
import { defineConfig } from 'vitest/config';

export default defineConfig({
  test: {
    coverage: {
      provider: 'v8',
      reporter: ['text', 'json', 'html', 'lcov'],
      lines: 90,        // Minimum 90% line coverage
      functions: 90,    // Minimum 90% function coverage
      branches: 85,     // Minimum 85% branch coverage
      statements: 90,   // Minimum 90% statement coverage
      exclude: [
        'node_modules/',
        'dist/',
        'coverage/',
        '**/*.test.ts',
        '**/*.test.tsx',
        'src/test/**',
      ],
    },
  },
});

✅ Coverage by Component Type

// Target coverage levels per component category
const COVERAGE_TARGETS = {
  // Core game systems - CRITICAL
  combatSystem: { unit: 95, e2e: 85 },
  vitalPointSystem: { unit: 95, e2e: 80 },
  trigramSystem: { unit: 95, e2e: 80 },
  animationSystem: { unit: 90, e2e: 75 },
  
  // Three.js components - MODERATE (harder to test)
  threejsComponents: { unit: 85, e2e: 70 },
  sceneComponents: { unit: 85, e2e: 70 },
  
  // UI components - HIGH
  reactComponents: { unit: 95, e2e: 80 },
  screens: { unit: 90, e2e: 85 },
  
  // Utility functions - MAXIMUM
  utilities: { unit: 100, e2e: 0 },
  constants: { unit: 100, e2e: 0 },
  
  // Audio system - HIGH
  audioSystem: { unit: 90, e2e: 75 },
  
  // State management - CRITICAL
  stateManagement: { unit: 95, e2e: 80 },
} as const;

2. Unit Testing Strategy (Vitest)

ALWAYS write comprehensive unit tests:

✅ Test File Organization

// ALWAYS place unit tests in __tests__ directory
src/
├── systems/
│   ├── combat/
│   │   ├── CombatSystem.ts
│   │   └── __tests__/
│   │       ├── CombatSystem.test.ts
│   │       ├── VitalPointSystem.test.ts
│   │       └── DamageCalculation.test.ts
│   ├── trigram/
│   │   ├── TrigramSystem.ts
│   │   └── __tests__/
│   │       └── TrigramSystem.test.ts

✅ Comprehensive Test Structure

import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
import { CombatSystem } from '../CombatSystem';
import { TRIGRAM_STANCES } from '@/types/constants';

describe('CombatSystem', () => {
  let combatSystem: CombatSystem;
  
  beforeEach(() => {
    // Setup fresh instance for each test
    combatSystem = new CombatSystem();
  });
  
  afterEach(() => {
    // Cleanup resources
    vi.clearAllMocks();
  });
  
  // Group related tests
  describe('Stance Management', () => {
    it('should initialize with Geon stance by default', () => {
      expect(combatSystem.currentStance).toBe('GEON');
    });
    
    it('should transition between all 8 trigram stances', () => {
      Object.keys(TRIGRAM_STANCES).forEach(stance => {
        combatSystem.setStance(stance);
        expect(combatSystem.currentStance).toBe(stance);
      });
    });
    
    it('should reject invalid stance names', () => {
      expect(() => combatSystem.setStance('INVALID')).toThrow();
    });
  });
  
  describe('Vital Point Targeting', () => {
    it('should detect all 70 vital points', () => {
      const vitalPoints = combatSystem.getVitalPoints();
      expect(vitalPoints).toHaveLength(70);
    });
    
    it('should calculate correct damage for vital point hit', () => {
      const damage = combatSystem.calculateVitalPointDamage({
        point: 'BAIHUI', // GV20
        force: 100,
        accuracy: 0.95,
      });
      
      expect(damage).toBeGreaterThan(100); // Vital point multiplier
      expect(damage).toBeLessThanOrEqual(200);
    });
    
    it('should apply reduced damage for missed vital points', () => {
      const missedDamage = combatSystem.calculateVitalPointDamage({
        point: 'BAIHUI',
        force: 100,
        accuracy: 0.3, // Poor accuracy
      });
      
      expect(missedDamage).toBeLessThan(100);
    });
  });
  
  describe('Performance', () => {
    it('should calculate combat within 5ms', () => {
      const start = performance.now();
      
      for (let i = 0; i < 1000; i++) {
        combatSystem.calculateDamage(100, 0.8, 'BAIHUI');
      }
      
      const duration = performance.now() - start;
      expect(duration).toBeLessThan(5); // <5ms per frame budget
    });
  });
  
  describe('Edge Cases', () => {
    it('should handle zero damage gracefully', () => {
      const damage = combatSystem.calculateDamage(0, 1.0, 'BAIHUI');
      expect(damage).toBe(0);
    });
    
    it('should handle negative force by clamping to zero', () => {
      const damage = combatSystem.calculateDamage(-50, 1.0, 'BAIHUI');
      expect(damage).toBe(0);
    });
    
    it('should handle accuracy outside 0-1 range', () => {
      expect(() => 
        combatSystem.calculateDamage(100, 1.5, 'BAIHUI')
      ).toThrow();
    });
  });
});

✅ Testing Three.js Components

import { render } from '@testing-library/react';
import { Canvas } from '@react-three/fiber';
import { describe, it, expect } from 'vitest';
import { CombatCharacter3D } from '../CombatCharacter3D';

describe('CombatCharacter3D', () => {
  // Helper to render Three.js components
  const render3D = (component: React.ReactElement) => {
    return render(
      <Canvas data-testid="test-canvas">
        <Suspense fallback={null}>
          {component}
        </Suspense>
      </Canvas>
    );
  };
  
  it('should render without crashing', () => {
    const { container } = render3D(
      <CombatCharacter3D 
        position={[0, 0, 0]} 
        stance="GEON" 
      />
    );
    
    const canvas = container.querySelector('canvas');
    expect(canvas).toBeInTheDocument();
  });
  
  it('should apply Korean theming colors', () => {
    const { container } = render3D(
      <CombatCharacter3D 
        position={[0, 0, 0]} 
        stance="GEON"
        data-testid="combat-character"
      />
    );
    
    // Verify component renders (color testing requires more complex setup)
    expect(container).toBeTruthy();
  });
  
  it('should update stance color when stance changes', () => {
    const { rerender } = render3D(
      <CombatCharacter3D position={[0, 0, 0]} stance="GEON" />
    );
    
    rerender(
      <Canvas>
        <CombatCharacter3D position={[0, 0, 0]} stance="TAE" />
      </Canvas>
    );
    
    // Verify re-render succeeds
    expect(true).toBe(true);
  });
});

3. E2E Testing Strategy (Cypress)

ALWAYS write E2E tests for user workflows:

✅ E2E Test Organization

// cypress/e2e/ - User workflow tests
cypress/
├── e2e/
│   ├── combat-system.cy.ts       // Combat gameplay flows
│   ├── trigram-selection.cy.ts   // Stance selection UI
│   ├── vital-points.cy.ts        // Vital point targeting
│   ├── intro-screen.cy.ts        // Navigation flows
│   └── performance.cy.ts         // 60fps validation

✅ Comprehensive E2E Test

describe('Combat System E2E', () => {
  beforeEach(() => {
    cy.visit('/');
    cy.get('[data-testid="start-button"]').click();
    cy.get('[data-testid="combat-screen"]').should('be.visible');
  });
  
  describe('Trigram Stance Selection', () => {
    it('should allow selecting all 8 trigram stances', () => {
      const stances = ['GEON', 'TAE', 'LI', 'JIN', 'SON', 'GAM', 'GAN', 'GON'];
      
      stances.forEach(stance => {
        cy.get(`[data-testid="stance-${stance}"]`).click();
        cy.get('[data-testid="current-stance"]')
          .should('contain', stance);
      });
    });
    
    it('should display bilingual Korean | English text', () => {
      cy.get('[data-testid="stance-GEON"]')
        .should('contain', '건')
        .and('contain', 'Heaven');
    });
    
    it('should show trigram symbol (☰)', () => {
      cy.get('[data-testid="stance-GEON"]')
        .should('contain', '☰');
    });
  });
  
  describe('Vital Point Targeting', () => {
    it('should highlight all 70 vital points', () => {
      cy.get('[data-testid="vital-point-overlay"]').click();
      cy.get('[data-testid^="vital-point-"]')
        .should('have.length', 70);
    });
    
    it('should show Korean and TCM names on hover', () => {
      cy.get('[data-testid="vital-point-BAIHUI"]').trigger('mouseover');
      cy.get('[data-testid="vital-point-tooltip"]')
        .should('contain', '백회')
        .and('contain', 'Baihui (GV20)');
    });
    
    it('should calculate critical damage on precise hit', () => {
      cy.get('[data-testid="vital-point-BAIHUI"]').click();
      cy.get('[data-testid="damage-indicator"]')
        .should('contain', 'CRITICAL')
        .and('have.css', 'color', 'rgb(255, 68, 68)'); // KOREAN_COLORS.CRITICAL_HIT
    });
  });
  
  describe('Combat Performance', () => {
    it('should maintain 60fps during combat', () => {
      cy.window().then(win => {
        let frameCount = 0;
        let lastTime = performance.now();
        
        const measureFPS = () => {
          const currentTime = performance.now();
          const deltaTime = currentTime - lastTime;
          
          if (deltaTime >= 1000) {
            const fps = frameCount / (deltaTime / 1000);
            expect(fps).to.be.greaterThan(55); // Allow 5fps tolerance
            frameCount = 0;
            lastTime = currentTime;
          }
          
          frameCount++;
          
          if (frameCount < 300) { // Test for 5 seconds
            requestAnimationFrame(measureFPS);
          }
        };
        
        requestAnimationFrame(measureFPS);
      });
    });
  });
  
  describe('Accessibility', () => {
    it('should be keyboard navigable', () => {
      cy.get('body').type('{tab}');
      cy.focused().should('have.attr', 'data-testid');
      
      // Test stance selection with number keys (1-8)
      cy.get('body').type('1');
      cy.get('[data-testid="current-stance"]').should('contain', 'GEON');
      
      cy.get('body').type('2');
      cy.get('[data-testid="current-stance"]').should('contain', 'TAE');
    });
    
    it('should have proper ARIA labels', () => {
      cy.get('[data-testid="stance-GEON"]')
        .should('have.attr', 'aria-label')
        .and('contain', '건')
        .and('contain', 'Heaven');
    });
    
    it('should meet WCAG 2.1 AA contrast standards', () => {
      cy.get('[data-testid="combat-screen"]').then($el => {
        const bgColor = $el.css('background-color');
        const textColor = $el.css('color');
        
        // Verify high contrast (manual check in CI)
        expect(bgColor).to.exist;
        expect(textColor).to.exist;
      });
    });
  });
});

4. Performance Testing Requirements

ALWAYS validate 60fps performance:

✅ Performance Test Pattern

describe('Performance - Combat System', () => {
  it('should complete combat calculation in <5ms', () => {
    const combatSystem = new CombatSystem();
    const iterations = 1000;
    
    const start = performance.now();
    
    for (let i = 0; i < iterations; i++) {
      combatSystem.calculateDamage(100, 0.85, 'BAIHUI');
    }
    
    const duration = performance.now() - start;
    const avgTime = duration / iterations;
    
    expect(avgTime).toBeLessThan(5); // <5ms per calculation
  });
  
  it('should handle 1000 vital point checks per frame', () => {
    const vitalPointSystem = new VitalPointSystem();
    
    const start = performance.now();
    
    for (let i = 0; i < 1000; i++) {
      vitalPointSystem.checkHit([
        Math.random() * 2 - 1,
        Math.random() * 2 - 1,
        Math.random() * 2 - 1,
      ]);
    }
    
    const duration = performance.now() - start;
    
    expect(duration).toBeLessThan(16.67); // 60fps = 16.67ms frame budget
  });
  
  it('should maintain 60fps during 28-bone animation', () => {
    const animationSystem = new SkeletalAnimationSystem();
    const frameCount = 300; // 5 seconds at 60fps
    
    const start = performance.now();
    
    for (let i = 0; i < frameCount; i++) {
      animationSystem.updateBones(0.0166); // 60fps delta
    }
    
    const duration = performance.now() - start;
    const avgFrameTime = duration / frameCount;
    
    expect(avgFrameTime).toBeLessThan(16.67); // Maintain 60fps
  });
});

5. Accessibility Testing Standards

ALWAYS ensure WCAG 2.1 Level AA compliance:

✅ Accessibility Test Pattern

describe('Accessibility - Combat UI', () => {
  it('should have proper semantic HTML structure', () => {
    const { container } = render(<CombatScreen width={1200} height={800} />);
    
    // Check for semantic elements
    expect(container.querySelector('main')).toBeInTheDocument();
    expect(container.querySelector('nav')).toBeInTheDocument();
  });
  
  it('should have ARIA labels on interactive elements', () => {
    const { getByRole } = render(<CombatScreen width={1200} height={800} />);
    
    const stanceButton = getByRole('button', { name: /건.*Heaven/i });
    expect(stanceButton).toHaveAttribute('aria-label');
  });
  
  it('should support keyboard navigation', () => {
    const { getByTestId } = render(<CombatScreen width={1200} height={800} />);
    const firstButton = getByTestId('stance-GEON');
    
    firstButton.focus();
    expect(document.activeElement).toBe(firstButton);
  });
  
  it('should meet WCAG 2.1 AA contrast ratio (4.5:1)', () => {
    // Use color contrast testing library or manual verification
    const textColor = KOREAN_COLORS.TEXT_PRIMARY; // 0xffffff
    const bgColor = KOREAN_COLORS.UI_BACKGROUND_DARK; // 0x0a0a0a
    
    // White on very dark = 20.3:1 contrast (exceeds WCAG AA 4.5:1)
    expect(textColor).toBe(0xffffff);
    expect(bgColor).toBe(0x0a0a0a);
  });
  
  it('should have focus indicators', () => {
    const { getByTestId } = render(<CombatScreen width={1200} height={800} />);
    const button = getByTestId('stance-GEON');
    
    button.focus();
    
    // Check for visible focus indicator (CSS outline or border)
    const styles = window.getComputedStyle(button);
    expect(
      styles.outline !== 'none' || 
      styles.border !== 'none'
    ).toBe(true);
  });
});

6. Common Testing Anti-Patterns to REJECT

Immediately flag and reject these patterns:

❌ Missing Test Files

// BAD: New component without tests
src/systems/grappling/GrapplingSystem.ts
// Missing: src/systems/grappling/__tests__/GrapplingSystem.test.ts

❌ Insufficient Test Coverage

// BAD: Only testing happy path
describe('CombatSystem', () => {
  it('should work', () => {
    const combat = new CombatSystem();
    expect(combat).toBeTruthy(); // Not enough!
  });
});

// GOOD: Comprehensive coverage
describe('CombatSystem', () => {
  it('should initialize with default values', () => { /* ... */ });
  it('should handle valid input', () => { /* ... */ });
  it('should reject invalid input', () => { /* ... */ });
  it('should handle edge cases', () => { /* ... */ });
  it('should meet performance targets', () => { /* ... */ });
});

❌ Missing data-testid Attributes

// BAD: Interactive element without test ID
<button onClick={handleClick}>
  공격 | Attack
</button>

// GOOD: Proper test ID for E2E testing
<button 
  data-testid="attack-button"
  aria-label="공격 | Attack"
  onClick={handleClick}
>
  공격 | Attack
</button>

❌ No Performance Tests

// BAD: Performance-critical code without performance tests
export function calculateDamage(force: number, accuracy: number): number {
  // Complex calculation
  return result;
}

// GOOD: Include performance validation
describe('calculateDamage Performance', () => {
  it('should complete in <5ms', () => {
    const start = performance.now();
    for (let i = 0; i < 1000; i++) {
      calculateDamage(100, 0.85);
    }
    const duration = performance.now() - start;
    expect(duration / 1000).toBeLessThan(5);
  });
});

❌ No Accessibility Tests

// BAD: UI component without accessibility validation
export const StanceSelector: React.FC = () => {
  return <div>Stance selection</div>;
};

// GOOD: Include accessibility tests
describe('StanceSelector Accessibility', () => {
  it('should have ARIA labels', () => { /* ... */ });
  it('should be keyboard navigable', () => { /* ... */ });
  it('should meet WCAG contrast standards', () => { /* ... */ });
});

7. Required Testing Patterns

Enforce these testing patterns:

✅ Complete Test Suite Structure

describe('ComponentName', () => {
  // Setup and teardown
  beforeEach(() => { /* Initialize */ });
  afterEach(() => { /* Cleanup */ });
  
  // Initialization tests
  describe('Initialization', () => {
    it('should initialize with default values', () => { /* ... */ });
    it('should accept custom configuration', () => { /* ... */ });
  });
  
  // Functionality tests
  describe('Core Functionality', () => {
    it('should handle valid input correctly', () => { /* ... */ });
    it('should reject invalid input', () => { /* ... */ });
    it('should maintain state correctly', () => { /* ... */ });
  });
  
  // Edge cases
  describe('Edge Cases', () => {
    it('should handle empty input', () => { /* ... */ });
    it('should handle boundary values', () => { /* ... */ });
    it('should handle concurrent operations', () => { /* ... */ });
  });
  
  // Performance tests
  describe('Performance', () => {
    it('should complete within performance budget', () => { /* ... */ });
    it('should scale with input size', () => { /* ... */ });
  });
  
  // Integration tests
  describe('Integration', () => {
    it('should integrate with dependent systems', () => { /* ... */ });
  });
});

✅ Mock Audio System for Testing

// src/test/setup.ts - Global test setup
import { vi } from 'vitest';

// Mock Web Audio API
global.AudioContext = vi.fn().mockImplementation(() => ({
  createGain: vi.fn().mockReturnValue({
    connect: vi.fn(),
    gain: { value: 1 },
  }),
  createOscillator: vi.fn().mockReturnValue({
    connect: vi.fn(),
    start: vi.fn(),
    stop: vi.fn(),
  }),
}));

// Mock Howler.js
vi.mock('howler', () => ({
  Howl: vi.fn().mockImplementation(() => ({
    play: vi.fn(),
    stop: vi.fn(),
    volume: vi.fn(),
  })),
}));

Enforcement Rules

Rule 1: No New Code Without Tests

IF (new feature or component added)
THEN (unit tests AND E2E tests MUST be included)
ELSE (reject the change)

Rule 2: Maintain Minimum 90% Coverage

IF (pull request submitted)
THEN (verify coverage meets 90% threshold)
ELSE (add tests to meet coverage requirement)

Rule 3: All Interactive Elements Need data-testid

IF (button, input, or interactive element added)
THEN (add data-testid attribute)
ELSE (add test ID before approval)

Rule 4: Performance Tests for Critical Code

IF (code affects combat, animation, or rendering)
THEN (include performance tests with <5ms budget)
ELSE (add performance validation)

Rule 5: Accessibility Tests for UI Components

IF (UI component added or modified)
THEN (include ARIA labels, keyboard nav, WCAG contrast tests)
ELSE (add accessibility tests)

Test Quality Checklist

Before approving any code change:

• Unit Tests: >90% coverage for new/modified code
• E2E Tests: User workflows covered with Cypress
• data-testid: All interactive elements have test IDs
• Performance: Critical code has <5ms performance tests
• Accessibility: WCAG 2.1 AA compliance validated
• Edge Cases: Boundary conditions and error cases tested
• Mocking: External dependencies properly mocked
• Korean Context: Bilingual text tested (Korean | English)
• Three.js: 3D components have Canvas-wrapped tests
• Documentation: Test purpose and scenarios documented

ISO 27001 Alignment

This skill enforces controls from:

• A.12.1 - Operational Procedures (Testing standards documented)
• A.14.2 - Security in Development Processes (Testing in SDLC)
• A.14.3 - Test Data (Test data management practices)
• A.18.2 - Compliance with Security Policies (Testing compliance)

NIST CSF 2.0 Alignment

• GV.PO-01: Testing policy established and communicated
• ID.RA-01: Asset vulnerabilities identified (via testing)
• PR.DS-06: Integrity checking through automated tests
• DE.AE-02: Event analysis capabilities (test failures)
• RS.AN-03: Analysis performed to understand root cause (test debugging)

CIS Controls v8.1 Alignment

• Control 4: Secure Configuration (validated through tests)
• Control 16: Application Software Security (comprehensive testing)
• Control 17: Incident Response Management (test failure handling)

Remember

Testing is not a checkbox—it is the foundation of quality. Every feature, every component, every line of code must be validated through comprehensive, meaningful tests.

When writing tests:

1. COVER - Achieve >90% coverage with meaningful tests
2. VALIDATE - Test happy paths, edge cases, and error conditions
3. PERFORM - Ensure code meets 60fps performance targets
4. ACCESS - Validate WCAG 2.1 Level AA accessibility
5. INTEGRATE - Test E2E user workflows with Cypress
6. AUTOMATE - Run tests in CI/CD pipeline

흑괘의 품질을 검증하라 - Validate the Quality of the Black Trigram