Each then() should return a value or throw Firebase cloud functions

Question

I am writing a cloud function for firebase using javascript but I am stuck, I don\'t know the exact meaning of error and unable to solve it.. The error states: 27:65 error

Answer 1

Change this:

    return admin.messaging().sendToDevice(token_id, payload).then(response => {

    console.log('This was the notification Feature');

  });

into this:

    return admin.messaging().sendToDevice(token_id, payload).then(response=>{
      console.log('This was the notification Feature');
      return true;
    },err=>
    {
      throw err;
    });

As the error says when using then you need to return a value.