uploadProgress callback doesn't fire.

[devloop11]

Hi everyone,

• react-native - 0.76.3
• expo - 52.0.11
• react-native-blob-util - 0.21.1

Platform: iOS

I faced an issue recently with uploading the progress bar on iOS simulator. The file was uploaded successfully but uploadProgress did not fire at all.

Here is a code of request service:

ReactNativeBlobUtil
        .fetch("POST", formattedUrl,{
        Accept: "application/json",
        "Content-Type": "multipart/form-data",
      }, [
          {
            filename: file.fileName,
            name: "file",
            type: file.mimeType,
            data: ReactNativeBlobUtil.wrap(formatedPath),
          },
        ])
        .uploadProgress({ interval: 500 }, (sent, total) => {
          console.log(sent, total);
          params?.onUploadCallback && params.onUploadCallback({ total, sent });
        })
        .then((response) => {
          /// handling response
       })

After digging deeply I found that native iOS ReactNativeBlobUtilRequest function was not called at all.
- (void) URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didSendBodyData:(int64_t)bytesSent totalBytesSent:(int64_t)totalBytesWritten totalBytesExpectedToSend:(int64_t)totalBytesExpectedToWrite

I could fix it by calling config method with {IOSBackgroundTask: true}. If I called it with false value the issue appeared again.

ReactNativeBlobUtil.config({ IOSBackgroundTask: true })
        .fetch({....rest of the code})

It needs to be marked in the uploading progress section because I spent almost a day to fix it. This is the only way to get uploading progress because Axios and XMLHttpRequest don't work for mobile.