16259-medium-to-primitive.ts

// ============= Test Cases =============
import type { Equal, Expect } from "./test-utils";

type PersonInfo = {
  name: "Tom";
  age: 30;
  married: false;
  addr: {
    home: "123456";
    phone: "13111111111";
  };
  hobbies: ["sing", "dance"];
  readonlyArr: readonly ["test"];
  fn: () => any;
};

type ExpectedResult = {
  name: string;
  age: number;
  married: boolean;
  addr: {
    home: string;
    phone: string;
  };
  hobbies: [string, string];
  readonlyArr: readonly [string];
  fn: Function;
};

type cases = [Expect<Equal<ToPrimitive<PersonInfo>, ExpectedResult>>];

// ============= Your Code Here =============
type Primitives = [string, number, bigint, boolean, symbol, null, undefined];

type GetPrimitive<T, P = Primitives> = P extends [infer F, ...infer R]
  ? T extends F
    ? F
    : GetPrimitive<T, R>
  : never;

type ToPrimitive<T> = T extends (...arg: any[]) => any
  ? Function
  : {
      [P in keyof T]: T[P] extends object
        ? ToPrimitive<T[P]>
        : GetPrimitive<T[P]>;
    };