[backend] fix: 修复异常处理和类型转换问题

frontend/node_modules/es-abstract/2015/GetIterator.js

@@ -0,0 +1,30 @@
+'use strict';
+
+var $TypeError = require('es-errors/type');
+
+var getIteratorMethod = require('../helpers/getIteratorMethod');
+var AdvanceStringIndex = require('./AdvanceStringIndex');
+var Call = require('./Call');
+var GetMethod = require('./GetMethod');
+
+var isObject = require('es-object-atoms/isObject');
+
+var ES = {
+	AdvanceStringIndex: AdvanceStringIndex,
+	GetMethod: GetMethod
+};
+
+// https://262.ecma-international.org/6.0/#sec-getiterator
+
+module.exports = function GetIterator(obj, method) {
+	var actualMethod = method;
+	if (arguments.length < 2) {
+		actualMethod = getIteratorMethod(ES, obj);
+	}
+	var iterator = Call(actualMethod, obj);
+	if (!isObject(iterator)) {
+		throw new $TypeError('iterator must return an object');
+	}
+
+	return iterator;
+};