When fetching data in a firebase cloud function from firestore we get is not assignable errors when using a converter - firebase

Question

I am writing a cloud function that needs to retrieve a document from firestore using get(). I then need to use this data, so I am trying to use a converter so I can use the object later on down the line. The converter uses FamilyRequest to specify fields. Here is the relevant code:
import * as functions from "firebase-functions";
import * as admin from "firebase-admin";
import * as firebase from 'firebase/app';
import 'firebase/auth';
import 'firebase/firestore';
admin.initializeApp();
const db = admin.firestore();
const settings = {timestampsInSnapshots: true};
db.settings(settings);
class FamilyRequest {
recipient;
sender;
familyId;
role;
senderIsModGuard;
constructor (recipient: string, sender: string, familyId: string, role: string, senderIsModGuard: boolean) {
this.recipient = recipient;
this.sender = sender;
this.familyId = familyId;
this.role = role;
this.senderIsModGuard = senderIsModGuard;
}
toString() {
return this.recipient + ', ' + this.sender + ', ' + this.familyId + ', ' + this.role + ', ' + this.senderIsModGuard;
}
}
const familyRequestConverter = {
toFirestore(famrequest: FamilyRequest): firebase.firestore.DocumentData {
return {
recipient: famrequest.recipient,
sender: famrequest.sender,
familyId: famrequest.familyId,
role: famrequest.role,
senderIsModGuard: famrequest.senderIsModGuard
};
},
fromFirestore(
snapshot: firebase.firestore.QueryDocumentSnapshot,
options: firebase.firestore.SnapshotOptions
): FamilyRequest {
const data = snapshot.data(options)!;
return new FamilyRequest(data.recipient, data.sender, data.familyId, data.role, data.senderIsModGuard);
}
};
export const acceptFamilyRequestFromFamilyModerator = functions.https.onCall(
async (data, context) => {
// Message text passed from the client.
if (data && context && context.auth && context.auth.uid) {
const groupId = data.text.groupId;
// Authentication info is automatically added to the request.
const uid = context.auth.uid;
const requid = data.text.uid;
const famrequestrecipient = data.text.famrequestrecipient;
const famrequestsender = data.text.famrequestsender; //this is the original sender of the famrequest
//Do sender/recipient checks here
const ref = await db.collection("famrequests")
.doc(uid)
.collection('myfamrequests')
.doc(famrequestrecipient)
.withConverter(familyRequestConverter)
.get()
.then(doc => { //This is simplified for now
if (doc.exists) {
return doc;
} else {
return null;
}
});
}
});
When entering this code into the IDE, the following errors come up:
No overload matches this call.
Overload 1 of 2, '(converter: null): DocumentReference', gave the following error.
Argument of type '{ toFirestore(famrequest: FamilyRequest): DocumentData; fromFirestore(snapshot: QueryDocumentSnapshot, options: SnapshotOptions): FamilyRequest; }' is not assignable to parameter of type 'null'.
Overload 2 of 2, '(converter: FirestoreDataConverter): DocumentReference', gave the following error.
Argument of type '{ toFirestore(famrequest: FamilyRequest): DocumentData; fromFirestore(snapshot: QueryDocumentSnapshot, options: SnapshotOptions): FamilyRequest; }' is not assignable to parameter of type 'FirestoreDataConverter'.
Types of property 'fromFirestore' are incompatible.
Type '(snapshot: QueryDocumentSnapshot, options: SnapshotOptions) => FamilyRequest' is not assignable to type '(snapshot: QueryDocumentSnapshot) => FamilyRequest'.ts(2769)
const familyRequestConverter: {
toFirestore(famrequest: FamilyRequest): firebase.firestore.DocumentData;
fromFirestore(snapshot: firebase.firestore.QueryDocumentSnapshot, options: firebase.firestore.SnapshotOptions): FamilyRequest;
}
I am not entirely sure what I am doing wrong as I am following the example code for converters here:
https://firebase.google.com/docs/firestore/query-data/get-data#web-version-8_3
very closely.
Any help is much appreciated.

Answer 1

I made the following change to familyRequestConverter that worked:
const familyRequestConverter = {
toFirestore: function(famrequest: FamilyRequest): firebase.firestore.DocumentData {
return {
recipient: famrequest.recipient,
sender: famrequest.sender,
familyId: famrequest.familyId,
role: famrequest.role,
senderIsModGuard: famrequest.senderIsModGuard,
};
},
fromFirestore: function(
snapshot: firebase.firestore.DocumentData
) {
const data = snapshot.data()!;
return new FamilyRequest(data.recipient, data.sender, data.familyId, data.role, data.senderIsModGuard);
}
};

Answer 2

This overloading error can be cause if you are missing either toFirestore or fromFirestore functions in the converter object which is passed to withConverter function.