array.prototype.flat ^{[![Version Badge][npm-version-svg]][package-url]}

[![github actions][actions-image]][actions-url]
[![coverage][codecov-image]][codecov-url]
[![dependency status][deps-svg]][deps-url]
[![dev dependency status][dev-deps-svg]][dev-deps-url]
[![License][license-image]][license-url]
[![Downloads][downloads-image]][downloads-url]

[![npm badge][npm-badge-png]][package-url]

An ES2019 spec-compliant Array.prototype.flat 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.flat depends on a receiver (the this value), the main export takes the array to operate on as the first argument.

Getting started

``sh
npm install --save array.prototype.flat
`

Usage/Examples

`js
var flat = require('array.prototype.flat');
var assert = require('assert');

var arr = [1, [2], [], 3, [[4]]];

assert.deepEqual(flat(arr, 1), [1, 2, 3, [4]]);
`

`js
var flat = require('array.prototype.flat');
var assert = require('assert');
/ when Array#flat is not present /
delete Array.prototype.flat;
var shimmedFlat = flat.shim();

assert.equal(shimmedFlat, flat.getPolyfill());
assert.deepEqual(arr.flat(), flat(arr));
`

`js
var flat = require('array.prototype.flat');
var assert = require('assert');
/ when Array#flat is present /
var shimmedIncludes = flat.shim();

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

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

Tests


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

[package-url]: https://npmjs.org/package/array.prototype.flat
[npm-version-svg]: https://versionbadg.es/es-shims/Array.prototype.flat.svg
[deps-svg]: https://david-dm.org/es-shims/Array.prototype.flat.svg
[deps-url]: https://david-dm.org/es-shims/Array.prototype.flat
[dev-deps-svg]: https://david-dm.org/es-shims/Array.prototype.flat/dev-status.svg
[dev-deps-url]: https://david-dm.org/es-shims/Array.prototype.flat#info=devDependencies
[npm-badge-png]: https://nodei.co/npm/array.prototype.flat.png?downloads=true&stars=true
[license-image]: https://img.shields.io/npm/l/array.prototype.flat.svg
[license-url]: LICENSE
[downloads-image]: https://img.shields.io/npm/dm/array.prototype.flat.svg
[downloads-url]: https://npm-stat.com/charts.html?package=array.prototype.flat
[codecov-image]: https://codecov.io/gh/es-shims/Array.prototype.flat/branch/main/graphs/badge.svg
[codecov-url]: https://app.codecov.io/gh/es-shims/Array.prototype.flat/
[actions-image]: https://img.shields.io/endpoint?url=https://github-actions-badge-u3jn4tfpocch.runkit.sh/es-shims/Array.prototype.flat
[actions-url]: https://github.com/es-shims/Array.prototype.flat/actions