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An ES spec-compliant Array.prototype.concat 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 spec.

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

Engines where this is needed

Note: this list is not exhaustive.

- Safari 10 - 13
- Chrome 48+ (v8 bug)
- node 6+

Example

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

var a = [1, 1, 1];
assert.deepEqual(concat(a, 1, 2), [1, 1, 1, 1, 2]);
assert.deepEqual(a, [1, 1, 1]);
`

`js
var concat = require('array.prototype.concat');
var assert = require('assert');
/ when Array#concat is not present /
delete Array.prototype.concat;
var shimmed = concat.shim();
assert.equal(shimmed, concat.getPolyfill());
assert.equal(shimmed, Array.prototype.concat);
assert.deepEqual([1, 2, 3].concat(1, 2, 3), concat([1, 2, 3], 1, 2, 3));
`

`js
var concat = require('array.prototype.concat');
var assert = require('assert');
/ when Array#concat is present /
var shimmed = concat.shim();
assert.equal(shimmed, Array.prototype.concat);
assert.deepEqual([1, 2, 3].concat(1, 2, 3), concat([1, 2, 3], 1, 2, 3));
`

Tests


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

[package-url]: https://npmjs.org/package/array.prototype.concat
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[license-url]: LICENSE
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