From d629414e5da96f01cc1d9eb4681b8ef9e2bc8168 Mon Sep 17 00:00:00 2001
From: Scott Jones <sjones@microsoft.com>
Date: Wed, 21 Oct 2020 17:20:07 -0700
Subject: [PATCH] ensure robustness against malformed runtime class name

---
 TestComponentCSharp/Class.cpp               | 43 ++++++++++++++-------
 TestComponentCSharp/Class.h                 |  2 +
 TestComponentCSharp/TestComponentCSharp.idl |  2 +
 UnitTest/TestComponentCSharp_Tests.cs       |  5 ++-
 4 files changed, 36 insertions(+), 16 deletions(-)

diff --git a/TestComponentCSharp/Class.cpp b/TestComponentCSharp/Class.cpp
index 0d560b829..5cee750b2 100644
--- a/TestComponentCSharp/Class.cpp
+++ b/TestComponentCSharp/Class.cpp
@@ -1274,16 +1274,16 @@ namespace winrt::TestComponentCSharp::implementation
         throw hresult_not_implemented();
     }
 
-    struct native_properties1 : winrt::implements<native_properties1, TestComponentCSharp::IProperties1>
+    TestComponentCSharp::IProperties1 Class::NativeProperties1()
     {
-        int32_t ReadWriteProperty()
+        struct native_properties1 : winrt::implements<native_properties1, TestComponentCSharp::IProperties1>
         {
-            return 42;
-        }
-    };
+            int32_t ReadWriteProperty()
+            {
+                return 42;
+            }
+        };
 
-    TestComponentCSharp::IProperties1 Class::NativeProperties1()
-    {
         return winrt::make<native_properties1>();
     }
 
@@ -1293,17 +1293,17 @@ namespace winrt::TestComponentCSharp::implementation
         virtual HRESULT __stdcall GetService(int32_t* type, int32_t* service) noexcept = 0;
     };
 
-    struct service_provider : winrt::implements<service_provider, WF::IInspectable, IServiceProviderInterop>
+    WF::IInspectable Class::ServiceProvider()
     {
-        HRESULT __stdcall GetService(int32_t* type, int32_t* service) noexcept override
+        struct service_provider : winrt::implements<service_provider, WF::IInspectable, IServiceProviderInterop>
         {
-            *service = 42;
-            return 0;
-        }
-    };
+            HRESULT __stdcall GetService(int32_t* type, int32_t* service) noexcept override
+            {
+                *service = 42;
+                return 0;
+            }
+        };
 
-    WF::IInspectable Class::ServiceProvider()
-    {
         return winrt::make<service_provider>();
     }
 
@@ -1330,5 +1330,18 @@ namespace winrt::TestComponentCSharp::implementation
         DataErrorsChangedEventArgs args(detach_abi(mock), take_ownership_from_abi_t());
         _dataErrorsChanged(*this, args);
     }
+
+    WF::IInspectable Class::BadRuntimeClassName()
+    {
+        struct bad_runtime_classname : winrt::implements<bad_runtime_classname, WF::IInspectable>
+        {
+            hstring GetRuntimeClassName()
+            {
+                return L"BadRuntimeClassName<T>";
+            }
+        };
+
+        return winrt::make<bad_runtime_classname>();
+    }
 }
 
diff --git a/TestComponentCSharp/Class.h b/TestComponentCSharp/Class.h
index c4eb027e5..7eae0b447 100644
--- a/TestComponentCSharp/Class.h
+++ b/TestComponentCSharp/Class.h
@@ -336,6 +336,8 @@ namespace winrt::TestComponentCSharp::implementation
         void ErrorsChanged(winrt::event_token const& token) noexcept;
         Windows::Foundation::Collections::IIterable<Windows::Foundation::IInspectable> GetErrors(hstring const& propertyName);
         void RaiseDataErrorChanged();
+
+        static Windows::Foundation::IInspectable BadRuntimeClassName();
     };
 }
 
diff --git a/TestComponentCSharp/TestComponentCSharp.idl b/TestComponentCSharp/TestComponentCSharp.idl
index 7a99e912d..249b68d65 100644
--- a/TestComponentCSharp/TestComponentCSharp.idl
+++ b/TestComponentCSharp/TestComponentCSharp.idl
@@ -330,6 +330,8 @@ namespace TestComponentCSharp
 
         // INotifyDataErrorInfo
         void RaiseDataErrorChanged();
+
+        static Object BadRuntimeClassName{ get; };
     }
 
     [threading(sta), marshaling_behavior(standard)]
diff --git a/UnitTest/TestComponentCSharp_Tests.cs b/UnitTest/TestComponentCSharp_Tests.cs
index f4abc7cef..865651dcf 100644
--- a/UnitTest/TestComponentCSharp_Tests.cs
+++ b/UnitTest/TestComponentCSharp_Tests.cs
@@ -478,8 +478,11 @@ public void TestCustomProjections()
             IntPtr service;
             serviceProvider.GetService(IntPtr.Zero, out service);
             Assert.Equal(new IntPtr(42), service);
-        }
 
+            // Ensure robustness with bad runtime class names (parsing errors, type not found, etc)
+            var badRuntimeClassName = Class.BadRuntimeClassName;
+            Assert.NotNull(badRuntimeClassName);
+        }
 
         [Fact]
         public void TestKeyValuePair()