How to await multiple functions with thousands of promises Firebase Functions - node.js

Question

I'm using the below code to delete all old data every night.
Each function works fine on it's own and if I create multiple schedule tasks, one for each function, it also works fine. However, when I combine them into a single Scheduled Task called scheduledCleanData, I'm receiving Error: Could not load the default credentials. Browse to https://cloud.google.com/docs/authentication/getting-started for more information.
at GoogleAuth.getApplicationDefaultAsync (/workspace/node_modules/google-auth-library/build/src/auth/googleauth.js:161:19)
at process._tickCallback (internal/process/next_tick.js:68:7)
As per this post, I believe this is caused by the functions not waiting for the callbacks, rather than problems with the credentials. However adding async or await keywords cause a parse error. Some of these collections need to delete thousands of records.
Any help how to modify this code to correctly wait would be greatly appreciated!
const functions = require('firebase-functions');
const admin = require('firebase-admin');
const client = require('firebase-tools');
admin.initializeApp(functions.config().firebase)
const db = admin.firestore();
const runtimeOpts = {
timeoutSeconds: 300,
memory: '1GB'
}
exports.scheduledCleanData = functions
.runWith(runtimeOpts)
.pubsub.schedule('0 3 * * *')
.timeZone('America/Chicago')
.onRun((context) => {
return cleanOldAssignments()
.then(cleanOldDuties())
.then(cleanOldEvents())
.then(console.info("scheduledCleanData Complete!"));
});
function cleanOldAssignments() {
const dateYesterday = new Date(new Date().getTime() - (24 * 60 * 60 * 1000)); // 24 hours
return db.collectionGroup('assignments').where('date', '<', dateYesterday).get()
.then(querySnapshot => {
console.info("Old assignments to remove: " + querySnapshot.size);
const promises = [];
querySnapshot.forEach(doc => {
promises.push(doc.ref.delete());
});
return Promise.all(promises);
});
}
function cleanOldDuties() {
const dateYesterday = new Date(new Date().getTime() - (24 * 60 * 60 * 1000)); // 24 hours
return db.collectionGroup('duties').where('date', '<', dateYesterday).get()
.then(querySnapshot => {
console.info("Old duties to remove: " + querySnapshot.size);
const promises = [];
querySnapshot.forEach(doc => {
promises.push(doc.ref.delete());
});
return Promise.all(promises);
});
}
function cleanOldEvents() {
const dateYesterday = new Date(new Date().getTime() - (24 * 60 * 60 * 1000)); // 24 hours
return db.collectionGroup('events').where('date', '<', dateYesterday).get()
.then(querySnapshot => {
console.info("Old events to remove: " + querySnapshot.size);
const promises = [];
querySnapshot.forEach(doc => {
promises.push(doc.ref.delete());
});
return Promise.all(promises);
});
}

Answer 1

If cleanOldDuties and cleanOldEvents both return more promises, your code is not taking them into account. You will need to explicitly return their values to propagate down the promise chain:
return cleanOldAssignments()
.then(() => { return cleanOldDuties() })
.then(() => { return cleanOldEvents() })
Without seeing the exact code of these other functions, it's not certain if this will work or not. Those functions have to be implemented correctly as well.
async/await is almost always a clearer way to express these sorts of things. You are probably just using them incorrectly as well.