### Commit Summary

- **TestSetup.cs**
  - Updated `CreateTestConfig` method to initialize `Config` with required properties using object initializer syntax.

- **ProxyIntegrationTests.cs**
  - Added null checks for `mockServer.Urls` before accessing it to prevent potential null reference exceptions.
  - Improved error handling for mock server URL access.

- **VRChatAuthenticationTests.cs**
  - Added null checks for `mockServer.Urls` before accessing it to prevent potential null reference exceptions.
  - Enhanced the mock server setup to include null checks for request body content.

- **Config.cs**
  - Added the `required` modifier to non-nullable properties in `ConfigAccount` and `iConfig` classes.
  - Updated the `Load` method to initialize the `Config` instance with required properties using object initializer syntax.

- **Program.cs**
  - Added a null check for `result.CloseStatus` in WebSocket handling to prevent potential null reference exceptions.

VRCAuthProxy/Config.cs

@@ -4,21 +4,26 @@ namespace VRCAuthProxy;
 
 public class ConfigAccount
 {
-    public string username { get; set; }
-    public string password { get; set; }
+    public required string username { get; set; }
+    public required string password { get; set; }
     public string? totpSecret { get; set; }
 }
 
 public class iConfig
 {
-    public List<ConfigAccount> accounts { get; set; }
+    public required List<ConfigAccount> accounts { get; set; }
 }
 
 // Load config from appsettings.json
 public class Config
 {
     private static Config? _instance;
-    public List<ConfigAccount> Accounts { get; set; }
+    public required List<ConfigAccount> Accounts { get; set; }
+
+    public Config()
+    {
+        Accounts = new List<ConfigAccount>();
+    }
 
     public static Config Instance
     {
@@ -31,8 +36,12 @@ public class Config
 
     public static Config Load()
     {
-        var config = new Config();
         var configPath = Path.Combine(AppContext.BaseDirectory, "appsettings.json");
+        var config = new Config
+        {
+            Accounts = new List<ConfigAccount>()
+        };
+
         if (File.Exists(configPath))
         {
             var json = File.ReadAllText(configPath);