Reference.set failed: First argument contains undefined - firebase

Question

I have created a firebase function that listen on onCreate event, however the DocumentSnapshot.data() is returning empty.
The function code is:
exports.createClientAccount = functions.firestore
.document('/userProfile/{userId}/clientList/{clientId}')
.onCreate(async (snap, context) => {
console.log('****snap.data(): ', snap.data()); //Showing Empty from the console.
return admin
.auth()
.createUser({
uid: context.params.clientId,
email: snap.data().email,
password: '123456789',
displayName: snap.data().fullName,
})
.then(userRecord => {
return admin
.database()
.ref(`/userProfile/${userRecord.uid}`)
.set({
fullName: userRecord.displayName, //ERROR here: Reference.set failed: First argument contains undefined
email: userRecord.email,
coachId: context.params.userId,
admin: false,
startingWeight: snap.data().startingWeight,
});
})
.catch(error => {
console.error('****Error creating new user',error);
});
});
The document IS created on the firebase database under
/userProfile/{userId}/clientList/{clientId}
clientId document created on the database
As per the documentation, onCreate listens when a new document is created and returns the snapshot of the data created through the DocumentSnapshot interface. However, I have checked from the console that snap.data() is empty. I don't understand why it is empty if the document is created successfully on the database.
image showing error returned by the functions when creating the userProfile
From the function code, return admin.auth.createUser({}) is creating the user as anonymous because snap.data().email is undefined, but it should create a non anonymous user.

Answer 1

First, please try to change document('/userProfile/{userId}/clientList/{clientId}') to document('userProfile/{userId}/clientList/{clientId}').
path should not start with /.
exports.createClientAccount = functions.firestore
.document('userProfile/{userId}/clientList/{clientId}')

Answer 2

At the end problem was that when I created the document with add({}) I was not including the fields in the instruction. This is the function that creates the client document and now the function gets triggered correctly.
async clientCreate(
fullName: string,
email: string,
startingWeight: number
): Promise<any> {
const newClientRef = await this.firestore
.collection(`userProfile/${this.userId}/clientList/`)
.add({
fullName,
email,
startingWeight: startingWeight * 1,
});
return newClientRef.update({
id: newClientRef.id
});
}
I was calling this.firestore.collection(...).add({}) with no fields, so when it happened, the cloud function got triggered and the DocumentSnapshot.data() was empty thus returning the Reference.set error. The cloud function createClientAccount is correct. Thanks.