An ES spec-compliant Array.prototype.push
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.push
depends on a receiver (the βthisβ value), the main export takes the array to operate on as the first argument.
Note: this list is not exhaustive.
- in node/chrome (including node 18-19):
push
fails to throw on a nonwritablelength
property - IE 8 and below, and pre-ES6 engines:
deleteCount
isn't defaulted tolength - start
until ES6 - Safari 5.0: sometimes it returns
undefined
- Safari 7/8: sparse arrays of size 1e5 or greater break
- Opera 12.15: breaks on small sparse arrays
var push = require('array.prototype.push');
var assert = require('assert');
var a = [1, 1, 1];
assert.equal(push(a, 1, 2), 5);
assert.deepEqual(a, [1, 1, 1, 1, 2]);
var push = require('array.prototype.push');
var assert = require('assert');
/* when Array#push is not present */
delete Array.prototype.push;
var shimmed = push.shim();
assert.equal(shimmed, push.getPolyfill());
assert.equal(shimmed, Array.prototype.push);
var a = [1, 2, 3];
var b = [1, 2, 3];
assert.equal(a.push(1, 2, 3), push(b, 1, 2, 3));
assert.deepEqual(a, b);
var push = require('array.prototype.push');
var assert = require('assert');
/* when Array#push is present */
var shimmed = push.shim();
assert.equal(shimmed, Array.prototype.push);
assert.deepEqual([1, 2, 3].push(1, 2, 3), push([1, 2, 3], 1, 2, 3));
Simply clone the repo, npm install
, and run npm test