[GitHub] shiftj18 opened a new issue #1895: callback of storage.getAllKeys not be called when storage is empty.

[GitBox <gi...@apache.org>]

shiftj18 opened a new issue #1895: callback of storage.getAllKeys not be called when storage is empty.
URL: https://github.com/apache/incubator-weex/issues/1895
 
 
   ## Describe the bug
   callback of storage.getAllKeys not be called when storage is empty.
   
   
   ## To Reproduce
   1. removeAllItems, by getAllKeys and removeItem.
   2. getAllKeys again, oops; callback is not called.
   
   
   ## Environment
   * Device: pc simulator
   * OS: mac
   * Version [e.g. 22]
   * Build from source [e.g. yes/no]
   
   
   ## Expected behavior
   the callback will be called, even if storage is empty. so, i can know getAllKeys is finished.
   
   
   ## Additional context
   code like: 
   `clearLocalStorage() and then readLocalStorage(), branch1 & branch2 both can be called.
   
   ```js
     readLocalStorage () {
       let storageList = [];
   
       const readAllFinish = () => {
         this.popModal({
           data: storageList
         });
       }
   
       AsyncStorage.getAllKeys(obj => {
         if (obj.result === 'success') {
           const { data: keys } = obj;
           keys.map((key, kIdx) => {
             AsyncStorage.getItem(key, (e) => {
               if (e.result === 'success') {
                 storageList.push({
                   key,
                   value: e.data
                 })
               }
               if (kIdx == keys.length - 1) {
                 readAllFinish();
               }
             })
           })
           if (!keys.length) { //branch2
             readAllFinish();
           }
         } else {   //branch1
           readAllFinish();
         }
       })
       // hack: callback of getAllKeys not call when sotrage is empty.
       setTimeout(() => {
         if (!storageList.length) {
           readAllFinish();
         }
       }, 200);
     }
   
     clearLocalStorage () {
       let failList = [];
   
       const clearAllFinish = () => {
         const failtips = `以下清除失败： ${failList.map(k => ('\n' + k))}`;
         toast('清空LocalStorage完成.', 400);
         if (failList.length) {
           toast(failtips, 3000);
         }
       }
   
       AsyncStorage.getAllKeys(obj => {
         if (obj.result === 'success') {
           
           const { data: keys } = obj;
           keys.map((key, kIdx) => {
             !!key && AsyncStorage.removeItem(key, (e) => {
               // remember failed key.
               if (e.result !== 'success') {
                 failList.push(key);
               }
             })
             if (kIdx == keys.length - 1) {
               clearAllFinish();
             }
           })
         }
       })
     }
   ```

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