User Preferences: Cannot read property 'preferences' of undefined

MongoDB University M220J: MongoDB for Java Developers
#1

All of my tests passed. But I have User Preferences: Cannot read property ‘preferences’ of undefined on my status page. What I shoud fix?

#2

I have the same situation.

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#3

I’ve faced with the same issue.

UPDATE:
I’ve finally solved it by changing implementation of addUser and createUserSession methods.
In addUser:

  1. You need to make sure that userId is valid. For example,
        if (user == null || user.isEmpty()) {
            throw new IncorrectDaoOperation("invalid user");
        }
  1. You need to make sure that user with the same id doesn’t exist. For example,
        final Bson filter = Filters.eq("email", user.getEmail());
        if (usersCollection.find(filter).limit(1).first() == null) {
            usersCollection.withWriteConcern(WriteConcern.MAJORITY).insertOne(user);
            return true;
        }
        return false;
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#4

What changes shoud I do in createUserSession?

#5

I’d suggest you to validate that

  1. input arguments are not null
        if (userId == null || jwt == null) {
            return false;
        }
  1. user with such id exists in database
        if (getUser(userId) == null) {
            return false;
        }
  1. session for given user doesn’t exist
        final Bson filter = Filters.eq("user_id", userId);
        final Session oldSession = sessionsCollection.find(filter).limit(1).first();
        if (oldSession == null) {
            final Session session = new Session(userId, jwt);
            sessionsCollection.insertOne(session);
        }
        return true;

Hope this helps

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#6

It works, thanks:+1:

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