# Final Verification Checklist

## 5.1 Enhanced Code Quality Check

### Top Priority

```typescript
const topPriority = {
  obeysTheGoldenRule: true,      // ✅ Only modify requested scope
  preservesWorkingCode: true,    // ✅ Preserve existing code
  respectsExistingStyle: true,   // ✅ Maintain existing style
};
```

### Type Safety

```typescript
const typeSafety = {
  noAnyType: true,               // ✅ No any type usage
  strictNullCheck: true,         // ✅ null/undefined check
  properTypeGuards: true,        // ✅ Use type guards
  genericTypesWhenNeeded: true,  // ✅ Use generic types
};
```

### Code Structure & Complexity

```typescript
const codeStructure = {
  singleResponsibility: true,    // ✅ Single Responsibility Principle
  functionUnder30Lines: true,    // ✅ Functions ≤30 lines (recommended), 50 allowed
  maxNesting3Levels: true,       // ✅ Max nesting 3 levels
  cyclomaticComplexity: 10,      // ✅ Cyclomatic complexity ≤ 10
  cognitiveComplexity: 15,       // ✅ Cognitive complexity ≤ 15
  maxParameters: 5,              // ✅ Max 5 parameters
  componentUnder50Lines: true,   // ✅ Component JSX ≤50 lines
};
```

### Halstead Metrics

```typescript
const halsteadMetrics = {
  vocabulary: true,              // ✅ Operator/operand diversity
  difficulty: true,              // ✅ Code comprehension difficulty
  effort: true,                  // ✅ Mental effort
  lowComplexity: true,           // ✅ Maintain low complexity
};
```

### Coupling & Cohesion

```typescript
const couplingCohesion = {
  looseCoupling: true,           // ✅ Loose coupling (≤ 7 dependencies)
  highCohesion: true,            // ✅ High cohesion (group related functions only)
  noCircularDeps: true,          // ✅ No circular dependencies
  dependencyInjection: true,     // ✅ Dependency injection pattern
};
```

### Error Handling

```typescript
const errorHandling = {
  hasErrorHandling: true,        // ✅ try-catch/error state
  hasLoadingState: true,         // ✅ Loading state
  hasFallbackUI: true,           // ✅ Fallback UI
  properErrorMessages: true,     // ✅ Clear error messages
  errorBoundaries: true,         // ✅ Use Error Boundaries
};
```

### Accessibility

```typescript
const accessibility = {
  hasAriaLabels: true,           // ✅ ARIA labels
  keyboardAccessible: true,      // ✅ Keyboard accessibility
  semanticHTML: true,            // ✅ Semantic HTML
  focusManagement: true,         // ✅ Focus management
  screenReaderFriendly: true,    // ✅ Screen reader support
};
```

### Performance

```typescript
const performance = {
  noUnnecessaryRenders: true,    // ✅ Prevent unnecessary re-renders
  memoizedExpensive: true,       // ✅ Memoize expensive operations
  lazyLoading: true,             // ✅ Lazy loading
  batchOperations: true,         // ✅ Batch API calls
  optimizedImages: true,         // ✅ Optimized images
  codesplitting: true,           // ✅ Code splitting
};
```

### Maintainability

```typescript
const maintainability = {
  hasJSDoc: true,                // ✅ Document key functions
  noMagicNumbers: true,          // ✅ No magic numbers
  consistentNaming: true,        // ✅ Consistent naming
  properComments: true,          // ✅ Appropriate comments
  testable: true,                // ✅ Testable structure
};
```

### Security

```typescript
const security = {
  noHardcodedSecrets: true,      // ✅ No hardcoded secrets
  inputValidation: true,         // ✅ Input validation
  xssPrevention: true,           // ✅ XSS prevention
  csrfProtection: true,          // ✅ CSRF protection
  sqlInjectionPrevention: true,  // ✅ SQL Injection prevention
};
```

## 5.2 Project Check

### Dependency Management

```typescript
const dependencies = {
  noUnusedDeps: true,            // ✅ No unused packages
  noDuplicateDeps: true,         // ✅ No duplicate functionality packages
  upToDateDeps: true,            // ✅ Keep up to date
  securePackages: true,          // ✅ No security vulnerabilities
};
```

### File Structure

```typescript
const fileStructure = {
  consistentStructure: true,     // ✅ Consistent folder structure
  noCircularDeps: true,          // ✅ No circular references
  logicalGrouping: true,         // ✅ Logical grouping
  clearNaming: true,             // ✅ Clear file names
};
```

### Bundle Optimization

```typescript
const bundleOptimization = {
  treeShaking: true,             // ✅ Tree shaking
  codeSplitting: true,           // ✅ Code splitting
  lazyLoading: true,             // ✅ Lazy loading
  minification: true,            // ✅ Minification
  compression: true,             // ✅ Compression (gzip/brotli)
};
```

## Checklist Usage

### Before Writing Code

```text
[ ] Clearly understand requirements
[ ] Identify existing code patterns
[ ] Confirm impact scope
[ ] Establish test plan
```

### While Writing Code

```text
[ ] Follow Single Responsibility Principle
[ ] Keep function length ≤30 lines (max 50)
[ ] Nesting depth ≤3 levels
[ ] Extract magic numbers to constants
[ ] Ensure type safety
```

### After Writing Code

```text
[ ] Type check passes
[ ] No linter warnings
[ ] Tests written and passing
[ ] Documentation complete
[ ] Ready for code review
```

### Before Commit

```text
[ ] Remove unnecessary code
[ ] Remove console logs
[ ] Clean up comments
[ ] Apply formatting
[ ] Write meaningful commit message
```

## Automated Verification Tools

### ESLint Configuration

```javascript
// .eslintrc.js
module.exports = {
  rules: {
    'complexity': ['error', 10],
    'max-depth': ['error', 3],
    'max-lines-per-function': ['error', 50],
    'max-params': ['error', 5],
    'no-magic-numbers': ['warn', { ignore: [0, 1, -1] }],
    '@typescript-eslint/no-explicit-any': 'error',
  },
};
```

### TypeScript Configuration

```json
// tsconfig.json
{
  "compilerOptions": {
    "strict": true,
    "noImplicitAny": true,
    "strictNullChecks": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true
  }
}
```

### Git Hooks (pre-commit)

```bash
#!/bin/sh
# .husky/pre-commit

# Type check
npm run type-check

# Linting
npm run lint

# Tests
npm run test

# Format check
npm run format:check
```

## Grade Criteria

| Grade | Score | Description |
|-------|-------|-------------|
| A+ | 95-100 | Perfect code quality |
| A | 90-94 | Excellent quality |
| B+ | 85-89 | Good quality |
| B | 80-84 | Improvement recommended |
| C+ | 75-79 | Improvement needed |
| C | 70-74 | Immediate improvement needed |
| F | < 70 | Refactoring required |

## Quick Check (1 minute)

```text
✅ Only modified requested scope?
✅ No any types?
✅ Functions ≤30 lines? (max 50)
✅ Nesting ≤3 levels?
✅ Error handling implemented?
✅ Magic numbers extracted to constants?
✅ Tests written?
```

All 7 Yes → Ready to deploy ✅
