Fix for tests randomly failing when run altogether

UnitTests/DI.cs

@@ -7,15 +7,17 @@ using UnitTests.Mock;
 
 namespace UnitTests;
 
+[TestClass]
 public class DI
 {
     private static IServiceProvider _serviceProvider;
 
-    private static IServiceProvider ConfigureServices()
+    [AssemblyInitialize]
+    public static void ConfigureServices(TestContext context)
     {
         if (_serviceProvider != null)
         {
-            return _serviceProvider;
+            return;
         }
 
         var services = new ServiceCollection();
@@ -29,11 +31,11 @@ public class DI
         services.AddSingleton<RandomUtil>();
         services.AddSingleton<HashUtil>();
 
-        return _serviceProvider = services.BuildServiceProvider();
+        _serviceProvider = services.BuildServiceProvider();
     }
 
     public static T GetService<T>() where T : notnull
     {
-        return ConfigureServices().GetRequiredService<T>();
+        return _serviceProvider.GetRequiredService<T>();
     }
 }