From 8f461884c967be466cbfa2457fd982835f66b730 Mon Sep 17 00:00:00 2001
From: Mackinnon Buck <mackinnon.buck@gmail.com>
Date: Wed, 9 Sep 2020 13:33:47 -0700
Subject: [PATCH] Update JSCallResultTypeHelper.cs (#25628)

* Update JSCallResultTypeHelper.cs and PublicAPI.Unshipped.txt

* CR feedback.

* Removed exception message
---
 .../JSInterop/JSCallResultTypeHelper.cs       | 23 +++++++++++++++----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/src/Shared/JSInterop/JSCallResultTypeHelper.cs b/src/Shared/JSInterop/JSCallResultTypeHelper.cs
index 82c3920c72..8bf1a547fc 100644
--- a/src/Shared/JSInterop/JSCallResultTypeHelper.cs
+++ b/src/Shared/JSInterop/JSCallResultTypeHelper.cs
@@ -1,15 +1,28 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System.Reflection;
+
 namespace Microsoft.JSInterop
 {
     internal static class JSCallResultTypeHelper
     {
+        // We avoid using Assembly.GetExecutingAssembly() because this is shared code.
+        private static readonly Assembly _currentAssembly = typeof(JSCallResultType).Assembly;
+
         public static JSCallResultType FromGeneric<TResult>()
-            => typeof(TResult) == typeof(IJSObjectReference)
-            || typeof(TResult) == typeof(IJSInProcessObjectReference)
-            || typeof(TResult) == typeof(IJSUnmarshalledObjectReference) ?
-                JSCallResultType.JSObjectReference :
-                JSCallResultType.Default;
+        {
+            if (typeof(TResult).Assembly == _currentAssembly
+                && (typeof(TResult) == typeof(IJSObjectReference)
+                || typeof(TResult) == typeof(IJSInProcessObjectReference)
+                || typeof(TResult) == typeof(IJSUnmarshalledObjectReference)))
+            {
+                return JSCallResultType.JSObjectReference;
+            }
+            else
+            {
+                return JSCallResultType.Default;
+            }
+        }
     }
 }