TypeScript Best Practices for 2024

TypeScript has become the go-to language for building scalable JavaScript applications. Let’s explore some best practices that will help you write better TypeScript code.

Use Strict Mode

Always enable strict mode in your tsconfig.json:

{
  "compilerOptions": {
    "strict": true
  }
}

This enables all strict type checking options and helps catch bugs early.

Avoid the any Type

The any type defeats the purpose of TypeScript. Instead, use:

• unknown for truly unknown types
• Proper type definitions
• Generics for flexible, type-safe code

function processData(data: unknown) {
  if (typeof data === 'string') {
    return data.toUpperCase();
  }
  throw new Error('Expected string');
}

Use Type Guards

Type guards help narrow down types safely:

interface User {
  name: string;
  age: number;
}
 
function isUser(obj: any): obj is User {
  return typeof obj.name === 'string' && typeof obj.age === 'number';
}

Leverage Utility Types

TypeScript provides powerful utility types:

• Partial<T>: Makes all properties optional
• Required<T>: Makes all properties required
• Pick<T, K>: Creates a type with selected properties
• Omit<T, K>: Creates a type without specific properties

interface User {
  id: number;
  name: string;
  email: string;
}
 
type UserUpdate = Partial<User>;
type PublicUser = Omit<User, 'email'>;

Conclusion

Following these best practices will help you write more robust TypeScript code. Remember, TypeScript is a tool to help you catch bugs early—embrace its type system!