[VFX] Template window can be empty because of an exception with package manager

Author: julienamsellem

Packages/com.unity.visualeffectgraph/Editor/TemplateWindow/VFXTemplateWindow.cs

@@ -215,34 +215,48 @@ private void OnCreate()
 
         private bool TryFindSample(string sampleName, out Sample sample)
         {
-            var startTime = Time.time;
-            var searchRequest = Client.Search(VisualEffectGraphPackageInfo.name, true);
-            while (!searchRequest.IsCompleted && Time.time - startTime < PackageManagerTimeout)
+            try
             {
-                Thread.Sleep(20);
-            }
-
-            if (searchRequest is { Result: { Length: 1 }, IsCompleted: true } && searchRequest.Result[0] is { } vfxPackageInfo)
-            {
-                // Workaround for UUM-63664
-                foreach (var extension in PackageManagerExtensions.Extensions)
+                var startTime = Time.time;
+                var searchRequest = Client.Search(VisualEffectGraphPackageInfo.name, true);
+                while (!searchRequest.IsCompleted && Time.time - startTime < PackageManagerTimeout)
                 {
-                    extension.OnPackageSelectionChange(vfxPackageInfo);
+                    Thread.Sleep(20);
                 }
 
-                foreach (var samplePackage in Sample.FindByPackage(VisualEffectGraphPackageInfo.name, null))
+                if (searchRequest is { Result: { Length: 1 }, IsCompleted: true } && searchRequest.Result[0] is { } vfxPackageInfo)
                 {
-                    if (string.Compare(samplePackage.displayName, sampleName, StringComparison.OrdinalIgnoreCase) ==
-                        0)
+                    // Workaround for UUM-63664
+                    foreach (var extension in PackageManagerExtensions.Extensions)
+                    {
+                        try
+                        {
+                            extension.OnPackageSelectionChange(vfxPackageInfo);
+                        }
+                        catch (Exception e)
+                        {
+                            Debug.LogWarning($"An error occured while trying to select a package extension.\n{e.Message}");
+                        }
+                    }
+
+                    foreach (var samplePackage in Sample.FindByPackage(VisualEffectGraphPackageInfo.name, null))
                     {
-                        sample = samplePackage;
-                        return true;
+                        if (string.Compare(samplePackage.displayName, sampleName, StringComparison.OrdinalIgnoreCase) ==
+                            0)
+                        {
+                            sample = samplePackage;
+                            return true;
+                        }
                     }
                 }
+                else
+                {
+                    Debug.LogWarning($"Could not determine if the {sampleName} package is installed");
+                }
             }
-            else
+            catch (Exception ex)
             {
-                Debug.LogWarning("Could not determine if the Learning Sample package is installed");
+                Debug.LogWarning($"Something went wrong while trying to retrieve {sampleName} package info\n{ex.Message}");
             }
 
             sample = default;

Tests/SRPTests/Projects/VisualEffectGraph_HDRP/Assets/AllTests/Editor/Tests/VFXTemplateWindowTest.cs

@@ -4,8 +4,11 @@
 using System.IO;
 using System.Linq;
 using System.Reflection;
+
+using Moq;
 using NUnit.Framework;
 
+using UnityEditor.PackageManager.UI;
 using UnityEditor.VFX.UI;
 using UnityEngine;
 using UnityEngine.TestTools;
@@ -415,6 +418,45 @@ public IEnumerator VFXView_Open_Two_View_Delete_Replace_Other_Content()
             yield return null;
         }
 
+        [UnityTest, Description("Covers UUM-95871")]
+        public IEnumerator Check_Install_Learning_Sample_Button()
+        {
+            var controller = VFXTestCommon.StartEditTestAsset();
+            yield return null;
+
+            // Create a mock package extension that throws to simulate a failing package
+            var throwingExtensionMock = new Mock<IPackageManagerExtension>();
+            throwingExtensionMock.Setup(x => x.OnPackageSelectionChange(It.IsAny<PackageManager.PackageInfo>())).Throws<NullReferenceException>();
+
+            try
+            {
+                PackageManagerExtensions.RegisterExtension(throwingExtensionMock.Object);
+
+                // Get template dropdown from the VFX graph toolbar
+                var vfxViewWindow = VFXViewWindow.GetWindow(controller.graph, false, true);
+                var templateDropDown = vfxViewWindow.rootVisualElement.Q<CreateFromTemplateDropDownButton>();
+                Assert.NotNull(templateDropDown);
+
+                // Open the template window
+                var onCreateNewMethod = templateDropDown.GetType().GetMethod("OnCreateNew", BindingFlags.Instance | BindingFlags.NonPublic);
+                Assert.NotNull(onCreateNewMethod);
+                onCreateNewMethod.Invoke(templateDropDown, null);
+
+                Assert.True(EditorWindow.HasOpenInstances<VFXTemplateWindow>());
+                var templateWindow = EditorWindow.GetWindow<VFXTemplateWindow>();
+                var installButton = templateWindow.rootVisualElement.Q<Button>("InstallButton");
+                Assert.NotNull(installButton);
+                Assert.True(installButton.enabledSelf);
+
+                // Check the failing extension package has been called otherwise the test does nothing useful
+                throwingExtensionMock.Verify(x => x.OnPackageSelectionChange(It.IsAny<PackageManager.PackageInfo>()), Times.Once);
+            }
+            finally
+            {
+                PackageManagerExtensions.Extensions.Remove(throwingExtensionMock.Object);
+            }
+        }
+
         internal static IEnumerator CheckNewVFXIsCreated(int templateIndex = 3)
         {
             // Make sure the project browser is opened