array-group-by-ponyfill

Array.prototype.groupBy ponyfill.

A proposal to make grouping of items in an array easier.

Install

npm install array-group-by-ponyfill --save

Usage

import groupBy from 'array-group-by-ponyfill';

groupBy([1, 2, 3, 4, 5], (value) => (value % 2 === 0 ? 'even' : 'odd'));

// { odd: [1, 3, 5], even: [2, 4] }

You can use named export preferNative if you wish to use native implementation if it’s available. In all other cases, ponyfill will be used. Beware of caveats!

API

groupBy(array, callback)

Returns: object

Group array items.

array

Type: any[]

Array to group.

callback

Type: Function

Callback which should return key with which to group array.

Argument	Type	Description
value	any	Current iteration value.
index	number	Current iteration index.
array	any[]	Original array reference.

Browser support

Tested in Chrome 72, Edge 15, Firefox 65 and should work in all modern browsers (support based on Browserslist configuration).

Test

Test suite is taken and modified from core-js test suite.

For automated tests, run npm run test:automated (append :watch for watcher support).

License

MIT © Ivan Nikolić