Safely reverting keys and values in a JS object

kvSwap.ts

const enum ChainType {
  test,
  main
 }

const prefixToChainType: stringToNumber = {
  "wit": ChainType.main,
  "twit": ChainType.test 
}

const chainTypeToPrefix = kvSwap(prefixToChainType)


type stringToNumber = { [key: string]: number }
type numberToString = { [key: number]: string }
type stringToString = { [key: string]: string }

function kvSwap(obj: numberToString): stringToNumber
function kvSwap(obj: stringToNumber): numberToString
function kvSwap(obj: stringToString): stringToString
function kvSwap(obj: stringToNumber | numberToString | stringToString): any {
  return Object
    .entries(obj)
    .reduce((acc, [key, value]) => {
      return {...acc, [value]: key}
    }, {})
}

const prefix = chainTypeToPrefix[ChainType.main]
const chainType = prefixToChainType[prefix]

const a = kvSwap({a: console.log})