10 TypeScript Tips Every Developer Should Know

TypeScript has become essential for building maintainable JavaScript applications. Here are 10 tips to level up your TypeScript skills.

1. Use const assertions for literal types

const config = {
endpoint: "/api",
timeout: 3000
} as const;
// config.endpoint is now "/api", not string

2. Leverage utility types

type User = {
id: string;
name: string;
email: string;
};

type UserPreview = Pick<User, "id" | "name">;
type PartialUser = Partial<User>;
type RequiredUser = Required<User>;

3. Use discriminated unions

type Result<T> = 
| { status: "success"; data: T }
| { status: "error"; error: Error };

4. Template literal types

type EventName = `on${Capitalize<string>}`;
// "onClick", "onSubmit", etc.

5. Use satisfies for type checking without widening

const palette = {
red: [255, 0, 0],
green: "#00ff00"
} satisfies Record<string, string | number[]>;

Conclusion

These tips will help you write more type-safe and maintainable TypeScript code.