mapKeys

100 bytes

since v12.1.0

Usage

Given an object and a toKey callback function, returns a new object with all the keys mapped through the toKey function. The callback is given both the key and value for each entry.

import * as _ from 'radashi'

const ra = {
  mode: 'god',
  power: 'sun',
}

_.mapKeys(ra, key => key.toUpperCase()) // => { MODE, POWER }
_.mapKeys(ra, (key, value) => value) // => { god: 'god', power: 'power' }

Type-safe alternatives

If your goal is to uppercase or lowercase the keys of an object, Radashi provides purpose-built functions for that, called upperize and lowerize. These functions have better type inference than mapKeys.

import * as _ from 'radashi'

const ra = {
  mode: 'god',
  power: 'sun',
}

const upperized = _.upperize(ra)
//    ^? { MODE: string, POWER: string }

const lowerized = _.lowerize(upperized)
//    ^? { mode: string, power: string }