I am using react-native-fs

RNFS.readDir(RNFetchBlob.fs.dirs.DocumentDir + "/data/" + id + "/").then((result) => {

      const numOfItems = result;
      let totalSum = numOfItems.reduce((n, { size }) => n + size, 0)
    });

i am using this code to get folder size. It is working fine as expected. But it is Stopping to calculate it as the folder have subfolders. Also not able to distinguish between files and folders. So please let me know if i have 5 or 10 subfolders then how can i get full folder size.