Firebase Auth USER_NOT_FOUND

Question

I am trying to create an account system that creates a new user and then sets the data of the user to Firebase Firestore.

function signUp(email, name, password, theme, privacy){
    firebase.auth().createUserWithEmailAndPassword(email, password).then(function(user) {
        var userId = user.uid;
        firebase.firestore().collection("Users").doc(`${userId}`).set({
            name: name,
            theme: theme,
            privacy: privacy
        }).then(() => {
            console.log("Document successfully written!");
        }).catch((error) => {
            console.error("Error writing document: ", error);
        });
      }).catch(function(error) {
        // Handle Errors here.
        var errorCode = error.code;
        var errorMessage = error.message;
        console.log('User did not sign up correctly');
        console.log(errorCode);
        console.console.log(errorMessage);
      });
}   

And here are my database rules

    match /Users/{userId}/{documents=**} {
      allow read, write: if isSignedIn() && isOwnerOfContent();
    }
    function isSignedIn(){
        return request.auth != null;
    }
    
    function isOwnerOfContent(){
        return request.auth.uid == userId;
    }

Error =

{error: {code: 400, message: "USER_NOT_FOUND",…}}
error: {code: 400, message: "USER_NOT_FOUND",…}
code: 400
errors: [{message: "USER_NOT_FOUND", domain: "global", reason: "invalid"}]
0: {message: "USER_NOT_FOUND", domain: "global", reason: "invalid"}
domain: "global"
message: "USER_NOT_FOUND"
reason: "invalid"
message: "USER_NOT_FOUND

Do you see anything wrong?

---

I also get this error:

signUp.js:135 Error writing document: FirebaseError: Missing or insufficient permissions. at new xr (prebuilt.js:184) at prebuilt.js:10608 at pr. (prebuilt.js:10560) at Kt (eventtarget.js:351) at jt (eventtarget.js:481) at mr.sa (webchannelbasetransport.js:368) at Qe (webchannelbase.js:2219) at Ue (channelrequest.js:822) at xe.N.Ca (channelrequest.js:703) at xe.N.Xa (channelrequest.js:564)

Answer 1

Your isOwnerOfContent uses userId, but that variable is not in scope:

function isOwnerOfContent(){
    return request.auth.uid == userId;
}

To make it work, either move isOwnerOfContent inside match /Users/{userId}/{documents=**}, or pass the userId value along in the call:

match /Users/{userId}/{documents=**} {
  allow read, write: if isSignedIn() && isOwnerOfContent(userId);
}
...    
function isOwnerOfContent(userId){
    return request.auth.uid == userId;
}