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Typescript utility types that you must know

Arafat on April 02, 2023

Hello everyone, Today, In this article, we will go through some beneficial and essential utility types in Typescript that can make your life easier...

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Gautam Vaishnav • Apr 2 '23

You are a great developer surly

Arafat • Apr 2 '23

Thanks for your nice comment😊.

Héctor Ramírez • Apr 8 '23

Concise and to the point. I foresee a terrific developer in you...

s_yasunaga • Apr 12 '23

Great post!
May I translate this article into Japanese and post it to community? (I'll definitely link this)

Arafat • Apr 12 '23

Sure, Go ahead!!!

byby • Apr 3 '23

Hot take: don't use any TS utility types :v

Pelle Wessman • Apr 4 '23

Why? What would be the reason to avoid them?

byby • Apr 4 '23

Over using utility types may lead to code that is difficult to understand and maintain. Especially nesting many types together. I know this is a soft opinion, the point is I saw many projects with very complex type definitions. Here's an example:

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

type VeryComplexUser = Readonly<Pick<User, "id">> &
  Partial<Omit<User, "email">> &
  { email: User["email"] | null } &
  { role: string } &
  Record<"email", string> & {
    role: User["name"] extends "admin" ? "admin" : "user";
  } & {
    name: User["name"];
  } & {
    id: { [K in keyof User["id"]]: User["id"][K] };
  } & {
    email: User["email"] & string;
  } & {
    role: Exclude<User["role"], "guest">;
  };