map-obj-async

map-obj-async

Asynchronously map object keys and values into a new object

This is a fork of map-obj and intends to expose the same API but with support for async mapping functions.

Install

npm install map-obj-async

Usage

import mapObject, {mapObjectSkip} from 'map-obj';

const newObject = await mapObject({foo: 'bar'}, (key, value) => [value, key]);
//=> {bar: 'foo'}

const newObject = await mapObject({FOO: true, bAr: {bAz: true}}, (key, value) => [key.toLowerCase(), value]);
//=> {foo: true, bar: {bAz: true}}

const newObject = await mapObject({FOO: true, bAr: {bAz: true}}, (key, value) => [key.toLowerCase(), value], {deep: true});
//=> {foo: true, bar: {baz: true}}

const newObject = await mapObject({one: 1, two: 2}, (key, value) => value === 1 ? [key, value] : mapObjectSkip);
//=> {one: 1}

const newObject = await mapObject({one: 1, two: 2}, async (key, value) => value === 1 ? [key, value] : mapObjectSkip);
//=> {one: 1}

API

mapObject(source, mapper, options?)

source

Type: object

The source object to copy properties from.

mapper

Type: (sourceKey, sourceValue, source) => [targetKey, targetValue, mapperOptions?] | mapObjectSkip | Promise<[targetKey, targetValue, mapperOptions?] | mapObjectSkip>

A mapping function.

mapperOptions

Type: object

shouldRecurse

Type: boolean
Default: true

Whether targetValue should be recursed.

Requires deep: true.

options

Type: object

deep

Type: boolean
Default: false

Recurse nested objects and objects in arrays.

target

Type: object
Default: {}

The target object to map properties on to.

mapObjectSkip

Return this value from a mapper function to exclude the key from the new object.

import mapObject, {mapObjectSkip} from 'map-obj';

const object = {one: 1, two: 2}
const mapper = (key, value) => value === 1 ? [key, value] : mapObjectSkip
const result = await mapObject(object, mapper);

console.log(result);
//=> {one: 1}

Related

• map-obj - Synchronously map object keys and values into a new object