Async Migrations: what's the intended way to do this?

[aclelland-netfore]

Hey,

I'm trying to figure out how I should be handling async migrations as it doesn't seem like Realm.open() seems like it waits for the migrations (The migration doesn't even work to begin with). I feel like I must be doing something stupid since this seems like it would be a fairly common use case.

const sessionRealmConfig: Realm.Configuration = {
  schema: [SessionRealm],
  schemaVersion: 1,
  onMigration: async (oldRealm: Realm, newRealm: Realm) => {
    if (oldRealm.schemaVersion < 1) {
      oldObjects = oldRealm.objects<OldSessionRealm>(SessionRealm.name!)
      newObjects = newRealm.objects<SessionRealm>(SessionRealm.name!)
      
      const data = await getSomeData();
  
      // error here when trying to access a realm after an await
      oldObjects.forEach((_, index) => {
        // set values on newObjects based on oldObjects and data
      });
    }
  }
}


// somewhere else
// hook used due to multiple Realms in my app so I can't use the Provider
const useSession = () => {
  const [realm, setRealm] = useState<Realm>();

  useEffect(() => {
    Realm.open(sessionRealmConfig).then(() => {
      setRealm() // this happens well before the error below and doesn't wait for migrations
    })
  }, [])

  // do some stuff and return stuff from the realm
}

I always get an error which is logged when it tries to access the realm object after the async call. I see this one a lot so I'm not sure if it's because of expo/metro or if it's just because I'm trying to access a Realm after an await.

Error: ENOENT: no such file or directory, open 'C:\-------\JavaScript'
    at Object.openSync (node:fs:600:3)
    at Object.readFileSync (node:fs:468:35)
    at getCodeFrame (C:\-------\node_modules\metro\src\Server.js:879:18)
    at Server._symbolicate (C:\-------\node_modules\metro\src\Server.js:962:22)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async Server._processRequest (C:\-------\node_modules\metro\src\Server.js:418:7) {
  errno: -4058,
  syscall: 'open',
  code: 'ENOENT',
  path: 'C:\\-------\\JavaScript'
}

What is the intended way I should be approaching this? Is there any documentation I could be pointed at or examples that I'm most likely missing? Do I need do make the migrations synchronous by fetching all the data I may need for a migration before I attempt to open the realm?