README.md

array.prototype.map

An ES5 spec-compliant Array.prototype.map 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.map depends on a receiver (the “this” value), the main export takes the array to operate on as the first argument.

Example

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

assert.deepEqual(map([1, 1, 1], function (x) { return x + 1; }), [2, 2, 2]);
assert.deepEqual(map([1, 0, 1], function (x) { return x + 1; }), [2, 1, 2]);

var map = require('array.prototype.map');
var assert = require('assert');
/* when Array#map is not present */
delete Array.prototype.map;
var shimmedMap = map.shim();
assert.equal(shimmedMap, map.getPolyfill());
var arr = [1, 2, 3];
var add4 = function (x) { return x + 4; };
assert.deepEqual(arr.map(add4), map(arr, add4));

var map = require('array.prototype.map');
var assert = require('assert');
/* when Array#map is present */
var shimmedMap = map.shim();
assert.equal(shimmedMap, Array.prototype.map);
assert.deepEqual(arr.map(add4), map(arr, add4));

Tests

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