Fix recursive Blob creation problem on Android

src/polyfill/Blob.js

    * @return {Blob} The Blob object instance itself
    */
   onCreated(fn:() => void):Blob {
-    log.verbose('register blob onCreated', this._onCreated.length)
+    log.verbose('#register blob onCreated', this._blobCreated)
     if(!this._blobCreated)
       this._onCreated.push(fn)
-    else
+    else {
       fn(this)
+    }
     return this
   }
 
   }
 
   _invokeOnCreateEvent() {
-    log.verbose('invoke create event')
+    log.verbose('invoke create event', this._onCreated)
     this._blobCreated = true
     let fns = this._onCreated
     for(let i in fns) {
-      if(typeof fns[i] === 'function')
+      if(typeof fns[i] === 'function') {
         fns[i](this)
+      }
     }
     delete this._onCreated
   }
   // start write blob data
   // return p.then(() => {
     for(let i in args) {
-      p = p.then((written) => {
+      p = p.then(function(written){
+        let arg = this
         if(written)
           size += written
-        log.verbose('mixed blob write', ...args[i], written)
-        return fs.appendFile.call(this, ...args[i])
-      })
+        log.verbose('mixed blob write', args[i], written)
+        return fs.appendFile(...arg)
+      }.bind(args[i]))
     }
     return p.then(() => Promise.resolve(size))
     // let promises = args.map((p) => {

src/polyfill/XMLHttpRequest.js

 
     if(this._readyState !== XMLHttpRequest.OPENED)
       throw 'InvalidStateError : XMLHttpRequest is not opened yet.'
-
+    let promise = Promise.resolve()
     this._sendFlag = true
     log.verbose('XMLHttpRequest send ', body)
     let {_method, _url, _headers } = this
     log.verbose(typeof body, body instanceof FormData)
 
     if(body instanceof Blob) {
-      body = RNFetchBlob.wrap(body.getRNFetchBlobRef())
+      promise = new Promise((resolve, reject) => {
+          body.onCreated((blob) => {
+            body = RNFetchBlob.wrap(body.getRNFetchBlobRef())
+            resolve()
+          })
+        })
     }
     else if(typeof body === 'object') {
       body = JSON.stringify(body)
+      promise = Promise.resolve()
     }
-    else
+    else {
       body = body ? body.toString() : body
-    this._task = RNFetchBlob
-                  .config({
-                    auto: true,
-                    timeout : this._timeout,
-                    binaryContentTypes : XMLHttpRequest.binaryContentTypes
-                  })
-                  .fetch(_method, _url, _headers, body)
-    this._task
-        .stateChange(this._headerReceived.bind(this))
-        .uploadProgress(this._uploadProgressEvent.bind(this))
-        .progress(this._progressEvent.bind(this))
-        .catch(this._onError.bind(this))
-        .then(this._onDone.bind(this))
+      promise = Promise.resolve()
+    }
+
+    promise.then(() => {
+      this._task = RNFetchBlob
+                    .config({
+                      auto: true,
+                      timeout : this._timeout,
+                      binaryContentTypes : XMLHttpRequest.binaryContentTypes
+                    })
+                    .fetch(_method, _url, _headers, body)
+      this._task
+          .stateChange(this._headerReceived.bind(this))
+          .uploadProgress(this._uploadProgressEvent.bind(this))
+          .progress(this._progressEvent.bind(this))
+          .catch(this._onError.bind(this))
+          .then(this._onDone.bind(this))
+    })
   }
 
   overrideMimeType(mime:string) {
           })
         break;
         default :
+        console.log(resp, resp.text())
           this._responseText = resp.text()
           this._response = this.responseText
           responseDataReady()