Moving a document and subcollection in a cloud function

move_collections.js

import functions from "firebase-functions";
import admin from "firebase-admin";

// client code
// firebase.auth().currentUser.getIdToken(/* forceRefresh */ true).then(function(idToken) {
// })

admin.initializeApp();

/**
 * If we want to move a doc, and subcollection from one location to another
 * /meetings/mid -> /archivedMeetings/mid
 * /meetings/mid/tickets -> /archivedMeetings/mid/tickets
 * https://us-central1-lets-point.cloudfunctions.net/archiveMeeting?
 */
exports.archiveMeeting = functions.https.onRequest(async (req, res) => {
  try {
      const db = admin.firestore();

      // Do we have everything we need to do this
      const { jwt = false, mid = false } = req.query;
      if (jwt === false || mid === false) {
        throw new Error('Missing some query params');
      }

      // Is the user allowed to do this
      const { uid } = await admin.auth().verifyIdToken(jwt);
      const meetingRef = db.doc(`/meetings/${mid}`);
      const archiveMeetingRef = db.doc(`/archivedMeetings/${mid}`);

      const m = await meetingRef.get();
      if (!m.exists) throw new Error('Meeting dne');

      const isParticipant = m.data().participantIDs[uid] !== undefined;
      if (!isParticipant) throw new Error('User must be in participant list');

      // Now we move the doc and subcollection
      await db.runTransaction(async t => {
        const [meeting, tickets] = await Promise.all([
          t.get(meetingRef).get(),
          t.get(meetingRef).collection('tickets'),
        ]);

        t.set(archiveMeetingRef, meeting.data());
        t.delete(meetingRef);

        tickets.docs.forEach(ticket => {
          t.create(archiveMeetingRef.collection('tickets').doc(ticket.id), ticket.data());
          t.delete(ticket.ref);
        });

        // any return value is converted into a resolved promise
        return null;
      });

      res.status(200).send();
    } catch (err) {
      console.error(err);
      res.status(500).send(err);
    }
});