firebase functions Property 'data' does not exist on type 'Change<DataSnapshot>'

Question

I'm trying to deploy firebase functions and I get the error

src/index.ts(132,31): error TS2339: Property 'data' does not exist on type 'Change'. src/index.ts(136,65): error TS2339: Property 'params' does not exist on type 'Change'. src/index.ts(142,18): error TS2339: Property 'data' does not exist on type 'Change'.

my code

    module.exports.onUserStatusChanged = functions.database
  .ref('/users/{uid}').onUpdate((event) => {
    // Get the data written to Realtime Database
    const eventStatus = event.data.val();

    // Then use other event data to create a reference to the
    // corresponding Firestore document.
    const userStatusFirestoreRef = firestore.doc(`users/${event.params.uid}`);

    // It is likely that the Realtime Database change that triggered
    // this event has already been overwritten by a fast change in
    // online / offline status, so we'll re-read the current data
    // and compare the timestamps.
    return event.data.ref.once("value").then((statusSnapshot) => {
      return statusSnapshot.val();
    }).then((status) => {
      console.log(status, eventStatus);
      // If the current timestamp for this data is newer than
      // the data that triggered this event, we exit this function.
      if (status.last_changed > eventStatus.last_changed) return;

      // Otherwise, we convert the last_changed field to a Date
      eventStatus.last_changed = new Date(eventStatus.last_changed);

      // ... and write it to Firestore.
      //return userStatusFirestoreRef.set(eventStatus);
      return userStatusFirestoreRef.update(eventStatus);
    });
  });

it shows red undeline

event.data.val()
event.params.uid

Answer 1

Change this:

module.exports.onUserStatusChanged = functions.database
.ref('/users/{uid}').onUpdate((event) => {
// Get the data written to Realtime Database
const eventStatus = event.data.val();

into this:

module.exports.onUserStatusChanged = functions.database
.ref('/users/{uid}').onUpdate((change,context) => {
// Get the data written to Realtime Database
const eventStatus = change.after.val();

Also change this:

event.params.uid

into this:

context.params.uid

more info here:

https://firebase.google.com/docs/functions/beta-v1-diff

Cloud functions have been updated and to retrieve data after onWrite is triggered, you need to use change that has two properties before and after, in this case use change.after.val()