Choices/src/scripts/src/lib/polyfills.js

/* eslint-disable */
(function () {
  // Production steps of ECMA-262, Edition 6, 22.1.2.1
  // Reference: https://people.mozilla.org/~jorendorff/es6-draft.html#sec-array.from
  if (!Array.from) {
    Array.from = (function() {
      let toStr = Object.prototype.toString;

      let isCallable = function(fn) {
        return typeof fn === 'function' || toStr.call(fn) === '[object Function]';
      };

      let toInteger = function(value) {
        let number = Number(value);
        if (isNaN(number)) {
          return 0;
        }
        if (number === 0 || !isFinite(number)) {
          return number;
        }
        return (number > 0 ? 1 : -1) * Math.floor(Math.abs(number));
      };

      let maxSafeInteger = Math.pow(2, 53) - 1;

      let toLength = function(value) {
        let len = toInteger(value);
        return Math.min(Math.max(len, 0), maxSafeInteger);
      };

      // The length property of the from method is 1.
      return function from(arrayLike /* , mapFn, thisArg */) {
        // 1. Let C be the this value.
        let C = this;

        // 2. Let items be ToObject(arrayLike).
        let items = Object(arrayLike);

        // 3. ReturnIfAbrupt(items).
        if (arrayLike == null) {
          throw new TypeError('Array.from requires an array-like object - not null or undefined');
        }

        // 4. If mapfn is undefined, then let mapping be false.
        let mapFn = arguments.length > 1 ? arguments[1] : void undefined;
        let T;
        if (typeof mapFn !== 'undefined') {
          // 5. else
          // 5. a If IsCallable(mapfn) is false, throw a TypeError exception.
          if (!isCallable(mapFn)) {
            throw new TypeError('Array.from: when provided, the second argument must be a function');
          }

          // 5. b. If thisArg was supplied, let T be thisArg; else let T be undefined.
          if (arguments.length > 2) {
            T = arguments[2];
          }
        }

        // 10. Let lenValue be Get(items, "length").
        // 11. Let len be ToLength(lenValue).
        let len = toLength(items.length);

        // 13. If IsConstructor(C) is true, then
        // 13. a. Let A be the result of calling the [[Construct]] internal method of C with an argument list containing the single item len.
        // 14. a. Else, Let A be ArrayCreate(len).
        let A = isCallable(C) ? Object(new C(len)) : new Array(len);

        // 16. Let k be 0.
        let k = 0;
        // 17. Repeat, while k < len… (also steps a - h)
        let kValue;
        while (k < len) {
          kValue = items[k];
          if (mapFn) {
            A[k] = typeof T === 'undefined' ? mapFn(kValue, k) : mapFn.call(T, kValue, k);
          } else {
            A[k] = kValue;
          }
          k += 1;
        }
        // 18. Let putStatus be Put(A, "length", len, true).
        A.length = len;
        // 20. Return A.
        return A;
      };
    }());
  }

  // Reference: https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/find
  if (!Array.prototype.find) {
    Array.prototype.find = function(predicate) {
      'use strict';

      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');
      }
      let list = Object(this);
      let length = list.length >>> 0;
      let thisArg = arguments[1];
      let value;

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

  function CustomEvent (event, params) {
    params = params || {
      bubbles: false,
      cancelable: false,
      detail: undefined,
    };
    let evt = document.createEvent('CustomEvent');
    evt.initCustomEvent(event, params.bubbles, params.cancelable, params.detail);
    return evt;
  }

  CustomEvent.prototype = window.Event.prototype;

  window.CustomEvent = CustomEvent;
}());