Creating a blob file to upload to firebase storage bucket when using react-native-image-picker

createBlobFromUri.js

// uri is the uri property on the response object from reactnative image picker
function convertUriToBlobFile = (uri) => { 
  return new Promise((resolve, reject) => {
    const xhr = new XMLHttpRequest();
    xhr.onload = function () {
      // return the blob
      resolve(xhr.response);
      // setBlob(xhr.response);
    };

    xhr.onerror = function () {
      // something went wrong
      reject(new Error('uriToBlob failed'));
    };
    // this helps us get a blob
    xhr.responseType = 'blob';
    xhr.open('GET', uri, true);

    // send back blob file created from uri
    xhr.send(null);
  });
};