array.prototype.at

array.prototype.at

An ESnext spec-compliant Array.prototype.at 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.

Because Array.prototype.at depends on a receiver (the this value), the main export takes the array to operate on as the first argument.

Getting started

npm install --save array.prototype.at

Usage/Examples

var at = require('array.prototype.at');
var assert = require('assert');

var arr = [1, [2], [], 3];

var results = at(arr, function (x, i) {
	assert.equal(x, arr[i]);
	return x;
});

assert.deepEqual(results, [1, 2, 3]);

var at = require('array.prototype.at');
var assert = require('assert');
/* when Array#at is not present */
delete Array.prototype.at;
var shimmedFlatMap = at.shim();

var mapper = function (x) { return [x, 1]; };

assert.equal(shimmedFlatMap, at.getPolyfill());
assert.deepEqual(arr.at(mapper), at(arr, mapper));

var at = require('array.prototype.at');
var assert = require('assert');
/* when Array#at is present */
var shimmedIncludes = at.shim();

var mapper = function (x) { return [x, 1]; };

assert.equal(shimmedIncludes, Array.prototype.at);
assert.deepEqual(arr.at(mapper), at(arr, mapper));

Tests

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

Changelog

v1.0.3 - 2021-09-30

Commits

• [Refactor] remove ESM entry points 667d2b9
• [Tests] add cases for Infinities; increase coverage 5158d4d
• [Deps] update es-abstract 32dec9f
• [actions] use node/install instead of node/run; use codecov action 6b9167b
• [Dev Deps] update eslint, tape be5df6a
• [Fix] ESM: ensure that imports work with es-abstract 2661b6e
• [Dev Deps] update @ljharb/eslint-config 59d59a8
• [Deps] update es-abstract fe9ce35