Swift - Firestore Document references must have an even number of segments, but

Question

Xcode is giving me this error message:

Document references must have an even number of segments, but users/hsiYfWgKz7MVOM77gMPkQYBHYJH2/wishlists has 3'

I have no idea why that error occurs because I thought there are 4 segments with this code:

let wishListName = self.popUpView.popUpTextField.text!

    let db = Firestore.firestore()
    let userID = Auth.auth().currentUser!.uid
    db.collection("users").document(userID).collection("wishlists").document(wishListName).setData(["name": wishListName]) { (error) in
        if error != nil {
            print("Error saving Wishlist")
        }
    }

Note: The document(wishListName) does not exist before. I am trying to auto save it with the specific ID wishListName . Every help ist appreciated :)

Answer 1

This typically happens when userID or wishListName is empty, as you end up with only 3 segments in that case.

If you log these values right before the line of code that throws an error, you can find out which one of the two is empty.