01130-medium-replacekeys.ts

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>>,
]

/******************************************************************************
* Answer
******************************************************************************/

type ReplaceKeys<U, T, Y> = any