type-challenges/medium-replacekeys.ts at master · ballsona/type-challenges · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
/* _____________ Your Code Here _____________ */

type ReplaceKeys<U, T, Y> = U extends unknown
  ? {
      [i in keyof U]: i extends T ? (i extends keyof Y ? Y[i] : never) : U[i];
    }
  : U;

/* _____________ Test Cases _____________ */
import type { Equal, Expect } from '@type-challenges/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>>,
];

/* _____________ Further Steps _____________ */
/*
  > Share your solutions: https://tsch.js.org/1130/answer
  > View solutions: https://tsch.js.org/1130/solutions
  > More Challenges: https://tsch.js.org
*/