/* Array find */

if (!Array.prototype.find) {
    Array.prototype.find = function(predicate) {
        if (this == null) {
            throw new TypeError('Array.prototype.find called on null or undefined');
        }
        if (typeof predicate !== 'function') {
            throw new TypeError('predicate must be a function');
        }
        var list = Object(this);
        var length = list.length >>> 0;
        var thisArg = arguments[1];
        var value;

        for (var i = 0; i < length; i++) {
            value = list[i];
            if (predicate.call(thisArg, value, i, list)) {
                return value;
            }
        }
        return undefined;
    };
}

/* Array findIndex */

if (!Array.prototype.findIndex) {
    Array.prototype.findIndex = function(predicate) {
        if (this === null) {
            throw new TypeError('Array.prototype.findIndex called on null or undefined');
        }
        if (typeof predicate !== 'function') {
            throw new TypeError('predicate must be a function');
        }
        var list = Object(this);
        var length = list.length >>> 0;
        var thisArg = arguments[1];
        var value;

        for (var i = 0; i < length; i++) {
            value = list[i];
            if (predicate.call(thisArg, value, i, list)) {
                return i;
            }
        }
        return -1;
    };
}

/* Array filter */

if (!Array.prototype.filter) {
    Array.prototype.filter = function(fun) {
        'use strict';

        if (this === void 0 || this === null) {
            throw new TypeError();
        }

        var t = Object(this);
        var len = t.length >>> 0;
        if (typeof fun !== 'function') {
            throw new TypeError();
        }

        var res = [];
        var thisArg = arguments.length >= 2 ? arguments[1] : void 0;
        for (var i = 0; i < len; i++) {
            if (i in t) {
                var val = t[i];
                if (fun.call(thisArg, val, i, t)) {
                    res.push(val);
                }
            }
        }

        return res;
    };
}

/* String includes */

if (!String.prototype.includes) {
    String.prototype.includes = function(search, start) {
        'use strict';
        if (typeof start !== 'number') {
            start = 0;
        }

        if (start + search.length > this.length) {
            return false;
        } else {
            return this.indexOf(search, start) !== -1;
        }
    };
}