Typed keyof output

example.ts

const obj = {
	str: 'hello',
	num: 1,
	bool: true
}

type MiscObject = typeof obj

const fun = <T extends keyof MiscObject>(key: T): MiscObject[T] => {
	return obj[key]
}

const val = fun('str') // type string
const val2 = fun('num') // type number
const val3 = fun('bool') // type boolean