Use realtime database Emulator from Unity

[DiscoverTravel]

[REQUIRED] Please fill in the following fields:

• Unity editor version: 2020.3.25f1
• Firebase Unity SDK version: 8.7.0
• Source you installed the SDK: .unitypackage (.unitypackage or Unity Package Manager)
• Problematic Firebase Component: Database (Auth, Database, etc.)
• Other Firebase Components in use: Database, Auth, Config (Auth, Database, etc.)
• Additional SDKs you are using: _____ (Facebook, AdMob, etc.)
• Platform you are using the Unity editor on: Windows (Mac, Windows, or Linux)
• Platform you are targeting: Emulator (desktop) (iOS, Android, and/or desktop)
• Scripting Runtime: IL2CPP (Mono, and/or IL2CPP)

[REQUIRED] Please describe the issue here:

Unity crash if use local instance of Database (Emulator)
In unity crash log:
ERROR: Could not initialize persistence: Unable to find app data directory.
Crash !!!

Steps to reproduce:

Use this code to connect to the emulator

Relevant Code:

FirebaseApp.CheckAndFixDependenciesAsync().ContinueWithOnMainThread(async task =>
        {
            var dependencyStatus = task.Result;
            if (dependencyStatus == DependencyStatus.Available)
            {
                FirebaseDatabase db = Firebase.Database.FirebaseDatabase.GetInstance("http://localhost:9000/?ns=myns");
                var snapshot = await db.GetReference("test").GetValueAsync();
                Debug.Log("The value: " + snapshot.Value);
            }
        });

[paulinon]

Hi @DiscoverTravel,

Could you provide the complete and detailed steps to replicate this behavior? I haven't encountered the issue using the information you provided so far.

[DiscoverTravel]

Hi @paulinon,
Thanks for the reply.

The steps are simple:

• I created a new unity 3D project on windows
• I have set up the Android platform
• I imported the realtime database package (sdk version 8.7.0)
• I hooked the MonoBehavior class which contains the code indicated in an element of the project
• I added the google-service.json file in the assets folder
• I started the database emulator
• I ran the indicated code

[paulinon]

Thanks for the additional information, @DiscoverTravel. Could you provide the full script containing the relevant code? I still haven't encountered the error message, and I think I may be missing something in my implementation.

[DiscoverTravel]

Hi @paulinon,
this is the code.
Remember to attach it as a script component to a GameObject of the project.

Best regards

using Firebase;
using Firebase.Database;
using Firebase.Extensions;
using UnityEngine;

public class FirebaseManager : MonoBehaviour
{

    void Start()
    {
        FirebaseApp.CheckAndFixDependenciesAsync().ContinueWithOnMainThread(task =>
        {

            var dependencyStatus = task.Result;
            if (dependencyStatus == DependencyStatus.Available)
            {

                Debug.Log("Firebase is ok");
                var app = FirebaseApp.DefaultInstance;

                FirebaseDatabase db = Firebase.Database.FirebaseDatabase.GetInstance("http://localhost:9000/?ns=myns");
                db.GetReference("test").GetValueAsync().ContinueWithOnMainThread(task =>
                   {
                       if (task.IsFaulted)
                       {
                           Debug.Log("Error");
                       }
                       else if (task.IsCompleted)
                       {
                           DataSnapshot snapshot = task.Result;
                           Debug.Log(snapshot.Value);
                       }
                   });
            }
            else
            {
                UnityEngine.Debug.LogError(System.String.Format("Could not resolve all Firebase dependencies: {0}", dependencyStatus));
            }
        });
    }

}