@diotoborg/necessitatibus-at

An ESnext spec-compliant Object.groupBy shim/polyfill/replacement that works as far down as ES3.

This package implements the es-shim API interface. It works in an ES3-supported environment and complies with the proposed spec.

Getting started

1npm install --save @diotoborg/necessitatibus-at

Usage/Examples

1var groupBy = require('@diotoborg/necessitatibus-at');
2var assert = require('assert');
3
4var arr = [0, 1, 2, 3, 4, 5];
5var parity = function (x) { return x % 2 === 0 ? 'even' : 'odd'; };
6
7var results = groupBy(arr, function (x, i) {
8    assert.equal(x, arr[i]);
9    return parity(x);
10});
11
12assert.deepEqual(results, {
13    __proto__: null,
14    even: [0, 2, 4],
15    odd: [1, 3, 5],
16});

1var groupBy = require('@diotoborg/necessitatibus-at');
2var assert = require('assert');
3/* when Object.groupBy is not present */
4delete Object.groupBy;
5var shimmed = groupBy.shim();
6
7assert.equal(shimmed, groupBy.getPolyfill());
8assert.deepEqual(Object.groupBy(arr, parity), groupBy(arr, parity));

1var groupBy = require('@diotoborg/necessitatibus-at');
2var assert = require('assert');
3/* when Array#group is present */
4var shimmed = groupBy.shim();
5
6assert.equal(shimmed, Object.groupBy);
7assert.deepEqual(Object.groupBy(arr, parity), groupBy(arr, parity));

Tests

Simply clone the repo, npm install, and run npm test