From 7909934a4c7da7b62d7a7496788896ab5c072b44 Mon Sep 17 00:00:00 2001
From: Javier Calvarro Nelson <jacalvar@microsoft.com>
Date: Mon, 1 Sep 2025 13:40:17 +0200
Subject: [PATCH] Add unsupported compat switch for property injection

---
 .../Components/src/ComponentFactory.cs        | 24 ++++++++++++-------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/src/Components/Components/src/ComponentFactory.cs b/src/Components/Components/src/ComponentFactory.cs
index 5a6c5b5c71c8..0618c9a4d20a 100644
--- a/src/Components/Components/src/ComponentFactory.cs
+++ b/src/Components/Components/src/ComponentFactory.cs
@@ -14,6 +14,11 @@ namespace Microsoft.AspNetCore.Components;
 
 internal sealed class ComponentFactory
 {
+    // This switch is unsupported and will be removed in a future version.
+    private static readonly bool _propertyInjectionDisabled =
+        AppContext.TryGetSwitch("Microsoft.AspNetCore.Components.Unsupported.DisablePropertyInjection", out var isDisabled) &&
+        isDisabled;
+
     private const BindingFlags _injectablePropertyBindingFlags
         = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic;
 
@@ -82,15 +87,18 @@ public IComponent InstantiateComponent(IServiceProvider serviceProvider, [Dynami
             throw new InvalidOperationException($"The component activator returned a null value for a component of type {componentType.FullName}.");
         }
 
-        if (component.GetType() == componentType)
-        {
-            // Fast, common case: use the cached data we already looked up
-            propertyInjector(serviceProvider, component);
-        }
-        else
+        if (!_propertyInjectionDisabled)
         {
-            // Uncommon case where the activator/resolver returned a different type. Needs an extra cache lookup.
-            PerformPropertyInjection(serviceProvider, component);
+            if (component.GetType() == componentType)
+            {
+                // Fast, common case: use the cached data we already looked up
+                propertyInjector(serviceProvider, component);
+            }
+            else
+            {
+                // Uncommon case where the activator/resolver returned a different type. Needs an extra cache lookup.
+                PerformPropertyInjection(serviceProvider, component);
+            }
         }
 
         return component;