perf[utils.js]: Add code comments to deepClone and remove redundant code

src/utils/index.js

@@ -246,6 +246,11 @@ export function debounce(func, wait, immediate) {
   }
 }
 
+/**
+ * This is just a simple version of deep copy
+ * Has a lot of edge cases bug
+ * If you want to use a perfect deep copy, use lodash's _.cloneDeep
+ */
 export function deepClone(source) {
   if (!source && typeof source !== 'object') {
     throw new Error('error arguments', 'shallowClone')
@@ -253,7 +258,6 @@ export function deepClone(source) {
   const targetObj = source.constructor === Array ? [] : {}
   Object.keys(source).forEach((keys) => {
     if (source[keys] && typeof source[keys] === 'object') {
-      targetObj[keys] = source[keys].constructor === Array ? [] : {}
       targetObj[keys] = deepClone(source[keys])
     } else {
       targetObj[keys] = source[keys]