Firebase函数检查数据库中的用户标识是否为当前用户标识

Question

我正致力于使用Firebase功能在Android设备之间发送通知。当A-Device向B-Device发送消息时，该消息将存储在A-Device Id和B-Device Id下的firebasedatabase中，如此问题是我写的功能总是检查A-Device因此，它始终将通知发送给A设备。这意味着当A-Device发送给B-Device时，通知将被发送到A-Device 这是我的Node.js代码。请帮助我;（

    const functions = require('firebase-functions');
const admin = require('firebase-admin');


admin.initializeApp(functions.config().firebase);
//const mId = firebase.auth().currentUser.getToken();
exports.sendNotification = functions.database.ref('/Messages/{mId}/{uId}/{messageId}').onWrite(event =>{
const mId = event.params.mId; //getting mId
const uId = event.params.uId; //getting uId
  const val = event.data.val(); //getting the values from event
  const from = val.from; //from value
  const type = val.type; //type value
  const message = val.message;





  console.log("user_name ",user_name);
  console.log("user_email ",user_email);


  const getDeviceToken = admin.database().ref(`/Users/${uId}/`).once('value');//getting device token function

  return getDeviceToken.then(snapshot =>{ //executing the function
  const DeviceToken = snapshot.val().DeviceToken;
  console.log ("Device Token is ",DeviceToken);
  if (from == mId) {
  delete  DeviceToken;
} 
  const getName = admin.database().ref(`/Users/${from}/`).once('value');//getting device token function

  return getName.then(snapshot =>{ //executing the function
    const Name = snapshot.val().Name;
    console.log ("Sender is ",Name);

  const payload = {
    data: {
      title: `${Name} sent you a message.`,
      body: `${message}`
    }
  };
  return admin.messaging().sendToDevice(DeviceToken,payload).then(response => {
    console.log (`Notification has been sent to  ${Name}`);
  });});
  });
});