Add warning message when form data format incorrect #90

src/android/src/main/java/com/RNFetchBlob/RNFetchBlobBody.java

             FormField field = new FormField(form.getMap(i));
             list.add(field);
             String data = field.data;
-            if (field.filename != null) {
+            if(data == null) {
+                RNFetchBlobUtils.emitWarningEvent("RNFetchBlob multipart request builder has found a field without `data` property, the field `"+ field.name +"` will be removed implicitly.");
+            }
+            else if (field.filename != null) {
                 // upload from storage
                 if (data.startsWith(RNFetchBlobConst.FILE_PREFIX)) {
                     String orgPath = data.substring(RNFetchBlobConst.FILE_PREFIX.length());

src/ios/RNFetchBlobReqBuilder.m

 #import "RNFetchBlobNetwork.h"
 #import "RNFetchBlobConst.h"
 #import "RNFetchBlobFS.h"
+#import "RCTLog.h"
 
 @interface RNFetchBlobReqBuilder()
 {
             {
                 i++;
                 getFieldData([form objectAtIndex:i]);
+                RCTLogWarn(@"RNFetchBlob multipart request builder has found a field without `data` or `name` property, the field will be removed implicitly.", field);
                 return;
             }
             contentType = contentType == nil ? @"application/octet-stream" : contentType;