TypeScript Best Practices for 2024

TypeScript has become the standard for building scalable JavaScript applications. Here are essential practices for writing better TypeScript code.

Type Everything

Avoid using any whenever possible:

typescript

// Bad
function processData(data: any) {
  return data.value;
}

// Good
interface Data {
  value: string;
  id: number;
}

function processData(data: Data) {
  return data.value;
}

Use Union Types

Union types provide flexibility with type safety:

typescript

type Status = 'pending' | 'approved' | 'rejected';

function updateStatus(status: Status) {
  // Type-safe status updates
}

Leverage Utility Types

TypeScript provides powerful utility types:

typescript

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

type PartialUser = Partial<User>;
type Read Readonly<User>;
type UserPreview = Pick<User, 'id' | 'name'>;

Generic Functions

Write reusable, type-safe functions:

typescript

function getFirstElement<T>(arr: T[]): T | undefined {
  return arr[0];
}

const firstNumber = getFirstElement([1, 2, 3]); // number | undefined
const firstString = getFirstElement(['a', 'b']); // string | undefined

Strict Mode

Enable strict mode in tsconfig.json:

json

{
  "compilerOptions": {
    "strict": true,
    "noImplicitAny": true,
    "strictNullChecks": true
  }
}

Conclusion

Following these best practices will help you write more maintainable and bug-free TypeScript code. Happy coding!