core-js/modules/web.dom-collections.iterator.js

var global = require('../internals/global');
var DOMIterables = require('../internals/dom-iterables');
var ArrayIteratorMethods = require('../modules/es.array.iterator');
var createNonEnumerableProperty = require('../internals/create-non-enumerable-property');
var wellKnownSymbol = require('../internals/well-known-symbol');

var ITERATOR = wellKnownSymbol('iterator');
var TO_STRING_TAG = wellKnownSymbol('toStringTag');
var ArrayValues = ArrayIteratorMethods.values;

for (var COLLECTION_NAME in DOMIterables) {
  var Collection = global[COLLECTION_NAME];
  var CollectionPrototype = Collection && Collection.prototype;
  if (CollectionPrototype) {
    // some Chrome versions have non-configurable methods on DOMTokenList
    if (CollectionPrototype[ITERATOR] !== ArrayValues) try {
      createNonEnumerableProperty(CollectionPrototype, ITERATOR, ArrayValues);
    } catch (error) {
      CollectionPrototype[ITERATOR] = ArrayValues;
    }
    if (!CollectionPrototype[TO_STRING_TAG]) {
      createNonEnumerableProperty(CollectionPrototype, TO_STRING_TAG, COLLECTION_NAME);
    }
    if (DOMIterables[COLLECTION_NAME]) for (var METHOD_NAME in ArrayIteratorMethods) {
      // some Chrome versions have non-configurable methods on DOMTokenList
      if (CollectionPrototype[METHOD_NAME] !== ArrayIteratorMethods[METHOD_NAME]) try {
        createNonEnumerableProperty(CollectionPrototype, METHOD_NAME, ArrayIteratorMethods[METHOD_NAME]);
      } catch (error) {
        CollectionPrototype[METHOD_NAME] = ArrayIteratorMethods[METHOD_NAME];
      }
    }
  }
}