typescript-standards

TypeScript Standards Skill

Guides you to write clean, type-safe TypeScript code following best practices.

When to Use

• Writing new TypeScript code
• Refactoring JavaScript to TypeScript
• Reviewing TypeScript for quality
• Setting up TypeScript projects

Critical Rules

Type Safety

• Always enable strict: true in tsconfig.json
• Avoid any - use unknown when type is uncertain
• Use explicit return types on public functions
• Enable noImplicitAny and strictNullChecks

Naming Conventions

• PascalCase for types, interfaces, classes
• camelCase for variables, functions, methods
• UPPER_SNAKE_CASE for constants
• Use descriptive names, avoid abbreviations

Code Organization

• One class/interface per file (preferably)
• Group related types in dedicated files
• Export types explicitly
• Use barrel exports (index.ts) for clean imports

Best Practices

• Prefer interface over type for object shapes
• Use discriminated unions for complex state
• Leverage generics for reusable code
• Use readonly for immutable properties
• Prefer const assertions for literal types

Workflow

1. Setup: Ensure strict mode is enabled
2. Write: Follow naming and type conventions
3. Review: Check for any usage and implicit types
4. Refine: Add explicit types where inference fails

Examples

Good

interface User {
  readonly id: string;
  name: string;
  email: string;
}

function getUserById(id: string): Promise<User | null> {
  // Implementation
}

Bad

type User = any;

function getUser(id) {
  return fetch(`/users/${id}`);
}

Related

• /react-typescript - React-specific TypeScript patterns
• /vue3-typescript - Vue 3 TypeScript integration