01130-medium-replacekeys.ts

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

type NodeA = {
  type: 'A';
  name: string;
  flag: number;
};

type NodeB = {
  type: 'B';
  id: number;
  flag: number;
};

type NodeC = {
  type: 'C';
  name: string;
  flag: number;
};

type ReplacedNodeA = {
  type: 'A';
  name: number;
  flag: string;
};

type ReplacedNodeB = {
  type: 'B';
  id: number;
  flag: string;
};

type ReplacedNodeC = {
  type: 'C';
  name: number;
  flag: string;
};

type NoNameNodeA = {
  type: 'A';
  flag: number;
  name: never;
};

type NoNameNodeC = {
  type: 'C';
  flag: number;
  name: never;
};

type Nodes = NodeA | NodeB | NodeC;
type ReplacedNodes = ReplacedNodeA | ReplacedNodeB | ReplacedNodeC;
type NodesNoName = NoNameNodeA | NoNameNodeC | NodeB;

type cases = [
  Expect<Equal<ReplaceKeys<Nodes, 'name' | 'flag', { name: number; flag: string }>, ReplacedNodes>>,
  Expect<Equal<ReplaceKeys<Nodes, 'name', { aa: number }>, NodesNoName>>
];

// ============= Your Code Here =============
type ReplaceKeys<U, T, Y> = {
  [P in keyof U]: P extends T // 判断是否是需要替换的key
    ? P extends keyof Y // 判断是否是Y的key
      ? Y[P]
      : never
    : U[P];
};