@lambrioanpm/unde-debitis-perferendis

An ES7/ES2016 spec-compliant Array.prototype.includes 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.includes depends on a receiver (the this value), the main export takes the array to operate on as the first argument.

Engines that need this package include:

• IE (all versions)
• Safari < 9
• Firefox < 43, and 99-101
• Chrome < 47
• Edge < 14
• node < 6

Getting started

1npm install --save @lambrioanpm/unde-debitis-perferendis

Usage

Basic usage: includes(array, value[, fromIndex=0])

1var includes = require('@lambrioanpm/unde-debitis-perferendis');
2var assert = require('assert');
3var arr = [ 'one', 'two' ];
4
5includes(arr, 'one'); // true
6includes(arr, 'three'); // false
7includes(arr, 'one', 1); // false

Example

1var arr = [
2	1,
3	'foo',
4	NaN,
5	-0
6];
7
8assert.equal(arr.indexOf(0) > -1, true);
9assert.equal(arr.indexOf(-0) > -1, true);
10assert.equal(includes(arr, 0), true);
11assert.equal(includes(arr, -0), true);
12
13assert.equal(arr.indexOf(NaN) > -1, false);
14assert.equal(includes(arr, NaN), true);
15
16assert.equal(includes(arr, 'foo', 0), true);
17assert.equal(includes(arr, 'foo', 1), true);
18assert.equal(includes(arr, 'foo', 2), false);

1/* when Array#includes is not present */
2delete Array.prototype.includes;
3var shimmedIncludes = includes.shim();
4
5assert.equal(shimmedIncludes, includes.getPolyfill());
6assert.equal(arr.includes('foo', 1), includes(arr, 'foo', 1));

1/* when Array#includes is present */
2var shimmedIncludes = includes.shim();
3
4assert.equal(shimmedIncludes, Array.prototype.includes);
5assert.equal(arr.includes(1, 'foo'), includes(arr, 1, 'foo'));

Tests

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