polyfill-service/polyfills/Array/prototype/includes/polyfill.js

A polyfill combinator

(function () {
	Object.defineProperty(Array.prototype, 'includes', {
		configurable: true,
		value: function includes (searchElement /*, fromIndex*/) {
			'use strict';
			var O = Object(this);
			var len = parseInt(O.length) || 0;
			if (len === 0) {
				return false;
			}
			var n = parseInt(arguments[1]) || 0;
			var k;
			if (n >= 0) {
				k = n;
			} else {
				k = len + n;
				if (k < 0) {
					k = 0;
				}
			}
			var currentElement;
			while (k < len) {
				currentElement = O[k];
				if (searchElement === currentElement ||
					(searchElement !== searchElement && currentElement !== currentElement)) {
					return true;
				}
				k++;
			}
			return false;
		},
		writable: true
	});
}());