test(NetworkManagerHUD): add unit test

Assets/Mirror/Core/NetworkManagerHUD.cs

@@ -9,12 +9,14 @@ namespace Mirror
     [HelpURL("https://mirror-networking.gitbook.io/docs/components/network-manager-hud")]
     public class NetworkManagerHUD : MonoBehaviour
     {
-        NetworkManager manager;
+        // internal so we can access it during unit tests
+        internal NetworkManager manager;
 
         public int offsetX;
         public int offsetY;
 
-        void Awake()
+        // internal so we can access it during unit tests
+        internal void Awake()
         {
             manager = GetComponent<NetworkManager>();
         }

Assets/Mirror/Tests/Editor/NetworkManagerHUD/NetworkManagerHUDTest.cs

@@ -0,0 +1,55 @@
+using NUnit.Framework;
+using UnityEngine;
+
+namespace Mirror.Tests
+{
+    public class NetworkManagerHUDTest : MirrorEditModeTest
+    {
+        [SetUp]
+        public override void SetUp()
+        {
+            base.SetUp();
+        }
+
+        [TearDown]
+        public override void TearDown()
+        {
+            base.TearDown();
+        }
+
+        [Test]
+        public void NetworkManagerHUDAttributesTest()
+        {
+            CreateGameObject(out GameObject manager, out NetworkManagerHUD managerHUD);
+
+            NetworkManagerHUD[] allHUDs = manager.GetComponents<NetworkManagerHUD>();
+
+            // Check if [RequireComponent(typeof(NetworkManager))] works
+            Assert.That(manager.GetComponent<NetworkManager>(), Is.Not.Null);
+            Assert.That(allHUDs.Length, Is.EqualTo(1));
+
+            manager.AddComponent<NetworkManagerHUD>();
+            allHUDs = manager.GetComponents<NetworkManagerHUD>();
+
+            // Check if [DisallowMultipleComponent] works
+            Assert.That(allHUDs.Length, Is.EqualTo(1));
+            Assert.That(allHUDs[0], Is.SameAs(managerHUD));
+        }
+
+        [Test]
+        public void NetworkManagerHUDLifecycleTest()
+        {
+            CreateGameObject(out GameObject managerGO, out NetworkManager networkManager);
+
+            NetworkManagerHUD managerHUD = managerGO.AddComponent<NetworkManagerHUD>();
+
+            Assert.That(managerHUD.manager, Is.Null, "manager should be null before Awake()");
+
+            // Must call Unity lifecycle methods manually in edit mode tests
+            managerHUD.Awake();
+
+            Assert.That(managerHUD.manager, Is.Not.Null, "manager should be set after Awake()");
+            //Assert.That(managerHUD.manager, Is.Not.Null, "manager should be set after Awake()");
+        }
+    }
+}