Goals

Realm JS is logging a warning with the message 'user' property will be overridden by ${this.identity} when the user calls createConfiguration on a Realm.Sync.User with a partial configuration object with a sync key. This happens even if the sync object does not have a user key - which I consider a bug.

Generally it is often annoying when a library uses the console to log messages, warnings or errors because it can be very hard to figure out is triggering the message to be logged - throwing an error is often much more helpful, as it contains a stack-trace. If the console is used, we need to be very explicit about what method triggered the console.

Expected Results

Specifically - don't warn if the sync object i the partial configuration do not provide a user key or throw instead to make it easier for a user to debug this behaviour.

Generally don't use console.log, console.warn and console.errors.

Actual Results

At https://github.com/realm/realm-js/blob/v2.14.2/lib/user-methods.js#L529

Steps to Reproduce

1. Create a Realm.Sync.User object.
2. Call user.createConfiguration({ sync: {} });
3. See "'user' property will be overridden by fd33cffb96e371d207d8e4a03f6c1434" being logged to the console.

Code Sample

const user = await Realm.Sync.User.registerWithProvider(url, {
  provider: "nickname",
  providerToken: nickname,
});
user.createConfiguration({ sync: {} })

Version of Realm and Tooling

• Realm JS SDK Version: 2.14.2
• Node or React Native: Node
• Client OS & Version: N/A
• Which debugger for React Native: N/A