Map values.

mapValues.ts

/**
 * 外提
 *
 * @param obj
 * @param fn
 * @returns remapped obj
 */
export function remap<P, T>(
	obj: { [key: string]: T },
	fn: (value: T, index: number) => P
): { [key: string]: P } {
	return Object.fromEntries(
		Object.entries(obj).map(([id, value], index) => [id, fn(value, index)])
	)
}

// EXAMPLE
const users = {
	fred: { age: 31, addr: 'steven str. road 31st'  },
	tom: { age: 24, addr: 'heaven str. road 12nd'  }
}

// {"fred":31,"tom":24}
const result = remap(users, user => user.age)