https://github.com/es-shims/Array.prototype.flatMap
An ESnext spec-compliant `Array.prototype.flatMap` shim/polyfill/replacement that works as far down as ES3.
https://github.com/es-shims/Array.prototype.flatMap
array ecmascript flatmap javascript polyfill shim
Last synced: 5 months ago
JSON representation
An ESnext spec-compliant `Array.prototype.flatMap` shim/polyfill/replacement that works as far down as ES3.
- Host: GitHub
- URL: https://github.com/es-shims/Array.prototype.flatMap
- Owner: es-shims
- License: mit
- Created: 2017-09-29T21:28:57.000Z (over 7 years ago)
- Default Branch: main
- Last Pushed: 2024-02-05T20:10:08.000Z (about 1 year ago)
- Last Synced: 2024-05-09T11:22:43.761Z (12 months ago)
- Topics: array, ecmascript, flatmap, javascript, polyfill, shim
- Language: JavaScript
- Homepage: https://tc39.github.io/proposal-flatMap/
- Size: 134 KB
- Stars: 32
- Watchers: 6
- Forks: 6
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Funding: .github/FUNDING.yml
- License: LICENSE
Awesome Lists containing this project
- awesome-ponyfills - array.prototype.flatmap - [`Array.prototype.flatMap`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/flatMap) (Arrays)
README
# array.prototype.flatmap [![Version Badge][npm-version-svg]][package-url]
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[![coverage][codecov-image]][codecov-url]
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[![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.flatMap` shim/polyfill/replacement that works as far down as ES3.
This package implements the [es-shim API](https://github.com/es-shims/api) interface. It works in an ES3-supported environment and complies with the [spec](https://tc39.es/ecma262/#sec-array.prototype.flatmap).
Because `Array.prototype.flatMap` 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.flatmap
```
## Usage/Examples
```js
var flatMap = require('array.prototype.flatmap');
var assert = require('assert');
var arr = [1, [2], [], 3];
var results = flatMap(arr, function (x, i) {
assert.equal(x, arr[i]);
return x;
});
assert.deepEqual(results, [1, 2, 3]);
```
```js
var flatMap = require('array.prototype.flatmap');
var assert = require('assert');
/* when Array#flatMap is not present */
delete Array.prototype.flatMap;
var shimmedFlatMap = flatMap.shim();
var mapper = function (x) { return [x, 1]; };
assert.equal(shimmedFlatMap, flatMap.getPolyfill());
assert.deepEqual(arr.flatMap(mapper), flatMap(arr, mapper));
```
```js
var flatMap = require('array.prototype.flatmap');
var assert = require('assert');
/* when Array#flatMap is present */
var shimmedIncludes = flatMap.shim();
var mapper = function (x) { return [x, 1]; };
assert.equal(shimmedIncludes, Array.prototype.flatMap);
assert.deepEqual(arr.flatMap(mapper), flatMap(arr, mapper));
```
## Tests
Simply clone the repo, `npm install`, and run `npm test`
[package-url]: https://npmjs.org/package/array.prototype.flatmap
[npm-version-svg]: https://versionbadg.es/es-shims/Array.prototype.flatMap.svg
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[dev-deps-url]: https://david-dm.org/es-shims/Array.prototype.flatMap#info=devDependencies
[npm-badge-png]: https://nodei.co/npm/array.prototype.flatmap.png?downloads=true&stars=true
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[license-url]: LICENSE
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