[backend] fix: 修复异常处理和类型转换问题

frontend/node_modules/es-iterator-helpers/test/helpers/testIterator.js

@@ -0,0 +1,7 @@
+'use strict';
+
+var iterate = require('iterate-iterator');
+
+module.exports = function testIterator(iterator, expected, t, msg) {
+	t.deepEqual(iterate(iterator), expected, 'iterator yields expected values: ' + msg);
+};