TypeScript Tips and Tricks

TypeScript has become an essential tool for modern web development. Here are some practical tips to help you write better TypeScript code.

Type Inference

TypeScript can infer types in many cases, so you don't always need to explicitly type everything:

// TypeScript infers the type automatically
const numbers = [1, 2, 3]; // number[]
const name = "John"; // string

Utility Types

TypeScript provides several utility types that can save you time:

Partial

Makes all properties optional:

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

type PartialUser = Partial<User>;
// All properties are now optional

Pick<T, K>

Select specific properties:

type UserName = Pick<User, 'name' | 'email'>;

Omit<T, K>

Exclude specific properties:

type UserWithoutAge = Omit<User, 'age'>;

Type Guards

Use type guards to narrow types:

function isString(value: unknown): value is string {
  return typeof value === 'string';
}

if (isString(value)) {
  // TypeScript knows value is string here
  console.log(value.toUpperCase());
}

Best Practices

1. Use strict mode: Enable strict type checking in tsconfig.json
2. Avoid any: Use unknown when the type is truly unknown
3. Leverage type inference: Don't over-type simple cases
4. Use interfaces for objects: Prefer interfaces over type aliases for object shapes

Conclusion

These tips should help you write more robust and maintainable TypeScript code. Remember, TypeScript is a tool to help you catch errors early and make your code more self-documenting.