impersonator/docs/08-code-quality.md

Code Quality Guide

Standards and practices for maintaining high code quality in the Impersonator project.

Code Standards

TypeScript

• Strict Mode: Enabled
• Type Safety: All functions typed
• No any: Avoid any type
• Interfaces: Use interfaces for object shapes
• Type Guards: Use type guards when needed

Code Style

• Formatting: Prettier
• Indentation: 2 spaces
• Semicolons: Required
• Quotes: Single quotes
• Trailing Commas: Yes

Naming Conventions

• Components: PascalCase (WalletManager)
• Functions: camelCase (validateAddress)
• Constants: UPPER_SNAKE_CASE (MAX_GAS_LIMIT)
• Types/Interfaces: PascalCase (SmartWalletConfig)
• Files: Match export name

Linting

ESLint Configuration

The project uses ESLint with Next.js configuration.

Run Linter:

pnpm lint

Fix Issues:

pnpm lint --fix

Common Rules

• No unused variables
• No console.log in production
• Consistent return statements
• Proper error handling
• No magic numbers

Formatting

Prettier Configuration

Automatic formatting on save (VS Code).

Manual Format:

npx prettier --write .

Formatting Rules

• 2 space indentation
• Single quotes
• Semicolons required
• Trailing commas
• 80 character line length (soft)

Code Review Checklist

Functionality

• Code works as intended
• Edge cases handled
• Error handling present
• No breaking changes

Code Quality

• Follows naming conventions
• Properly typed
• No magic numbers
• Comments where needed
• No code duplication

Security

• Input validation
• Secure storage used
• Authorization checks
• No sensitive data exposed

Testing

• Tests written
• Tests passing
• Coverage maintained
• Edge cases tested

Documentation

• JSDoc comments
• README updated if needed
• Changelog updated
• Breaking changes documented

Best Practices

1. Function Design

// ✅ Good: Single responsibility, typed, documented
/**
 * Validates Ethereum address
 * @param address - Address to validate
 * @returns Validation result with checksummed address
 */
function validateAddress(address: string): ValidationResult {
  // Implementation
}

// ❌ Bad: Multiple responsibilities, no types
function process(address) {
  // Does too much
}

2. Error Handling

// ✅ Good: Proper error handling
try {
  const result = await operation();
  return result;
} catch (error: any) {
  monitoring.error("Operation failed", error);
  throw new Error("Operation failed");
}

// ❌ Bad: Swallowed errors
try {
  await operation();
} catch (error) {
  // Silent failure
}

3. Constants

// ✅ Good: Constants extracted
import { SECURITY } from "@/utils/constants";
const maxGas = SECURITY.MAX_GAS_LIMIT;

// ❌ Bad: Magic numbers
const maxGas = 10000000;

4. Type Safety

// ✅ Good: Proper typing
interface Config {
  address: string;
  networkId: number;
}

function createWallet(config: Config): Promise<Wallet> {
  // Implementation
}

// ❌ Bad: No types
function createWallet(config) {
  // Implementation
}

5. Component Structure

// ✅ Good: Clean component
export default function WalletManager() {
  const { activeWallet } = useSmartWallet();
  const [loading, setLoading] = useState(false);

  const handleAction = useCallback(async () => {
    // Implementation
  }, [dependencies]);

  return (
    <Box>
      {/* JSX */}
    </Box>
  );
}

// ❌ Bad: Messy component
export default function WalletManager() {
  // Too much logic
  // Unclear structure
  // No memoization
}

Code Metrics

Complexity

• Cyclomatic Complexity: < 10 per function
• Function Length: < 50 lines
• File Length: < 500 lines
• Component Props: < 10 props

Maintainability

• Code Duplication: < 5%
• Test Coverage: > 80%
• Documentation: All public APIs
• Comments: Explain "why" not "what"

Refactoring Guidelines

When to Refactor

• Code duplication detected
• Function too long/complex
• Poor naming
• Hard to test
• Performance issues

Refactoring Steps

1. Write tests first
2. Make small changes
3. Run tests frequently
4. Keep functionality same
5. Improve incrementally

Documentation Standards

JSDoc Comments

/**
 * Validates Ethereum address with checksum verification
 * @param address - The Ethereum address to validate
 * @returns Validation result with checksummed address if valid
 * @example
 * const result = validateAddress("0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb");
 * if (result.valid) {
 *   const checksummed = result.checksummed!;
 * }
 */
export function validateAddress(address: string): ValidationResult {
  // Implementation
}

README Updates

Update README when:

• Adding new features
• Changing setup process
• Updating dependencies
• Breaking changes

Performance Considerations

Optimization

• Use useMemo for expensive calculations
• Use useCallback for callbacks
• Lazy load heavy components
• Code split by route
• Optimize images

Monitoring

• Track performance metrics
• Monitor bundle size
• Check render times
• Profile slow operations

Dependency Management

Adding Dependencies

1. Check if already exists
2. Verify security
3. Check bundle size
4. Review documentation
5. Test thoroughly

Updating Dependencies

# Check for updates
pnpm outdated

# Update dependencies
pnpm update

# Security audit
pnpm audit

CI/CD Quality Gates

Automated Checks

• Linting passes
• Tests pass
• Coverage maintained
• Build succeeds
• Security audit clean

Manual Review

• Code review required
• Architecture review for large changes
• Security review for sensitive changes

Tools

VS Code Extensions

• ESLint
• Prettier
• TypeScript
• Jest
• GitLens

Pre-commit Hooks

Consider adding:

• Linting
• Formatting
• Tests
• Type checking

Resources

• TypeScript Style Guide
• React Best Practices
• Clean Code Principles