From 38c013380338fa9901bb5ed3488d8d5c43a94acc Mon Sep 17 00:00:00 2001
From: Manodasan Wignarajah <mawign@microsoft.com>
Date: Tue, 16 Aug 2022 10:13:07 -0700
Subject: [PATCH] Project experimental attribute (#1244)

---
 .../CustomExperimentClass.cpp                 | 17 ++++++++++++++++
 .../CustomExperimentClass.h                   | 20 +++++++++++++++++++
 .../TestComponentCSharp.idl                   |  9 +++++++++
 .../TestComponentCSharp.vcxproj               |  2 ++
 .../TestComponentCSharp.vcxproj.filters       |  2 ++
 .../UnitTest/TestComponentCSharp_Tests.cs     |  7 +++++++
 src/cswinrt/code_writers.h                    |  3 ++-
 7 files changed, 59 insertions(+), 1 deletion(-)
 create mode 100644 src/Tests/TestComponentCSharp/CustomExperimentClass.cpp
 create mode 100644 src/Tests/TestComponentCSharp/CustomExperimentClass.h

diff --git a/src/Tests/TestComponentCSharp/CustomExperimentClass.cpp b/src/Tests/TestComponentCSharp/CustomExperimentClass.cpp
new file mode 100644
index 000000000..4527c67d6
--- /dev/null
+++ b/src/Tests/TestComponentCSharp/CustomExperimentClass.cpp
@@ -0,0 +1,17 @@
+#include "pch.h"
+#include "CustomExperimentClass.h"
+#include "CustomExperimentClass.g.cpp"
+
+namespace winrt::TestComponentCSharp::implementation
+{
+    int32_t CustomExperimentClass::Value()
+    {
+        return 4;
+    }
+    void CustomExperimentClass::Value(int32_t value)
+    {
+    }
+    void CustomExperimentClass::f()
+    {
+    }
+}
diff --git a/src/Tests/TestComponentCSharp/CustomExperimentClass.h b/src/Tests/TestComponentCSharp/CustomExperimentClass.h
new file mode 100644
index 000000000..6dfe2d15f
--- /dev/null
+++ b/src/Tests/TestComponentCSharp/CustomExperimentClass.h
@@ -0,0 +1,20 @@
+#pragma once
+#include "CustomExperimentClass.g.h"
+
+namespace winrt::TestComponentCSharp::implementation
+{
+    struct CustomExperimentClass : CustomExperimentClassT<CustomExperimentClass>
+    {
+        CustomExperimentClass() = default;
+
+        int32_t Value();
+        void Value(int32_t value);
+        void f();
+    };
+}
+namespace winrt::TestComponentCSharp::factory_implementation
+{
+    struct CustomExperimentClass : CustomExperimentClassT<CustomExperimentClass, implementation::CustomExperimentClass>
+    {
+    };
+}
\ No newline at end of file
diff --git a/src/Tests/TestComponentCSharp/TestComponentCSharp.idl b/src/Tests/TestComponentCSharp/TestComponentCSharp.idl
index 2f44d0827..17af1636b 100644
--- a/src/Tests/TestComponentCSharp/TestComponentCSharp.idl
+++ b/src/Tests/TestComponentCSharp/TestComponentCSharp.idl
@@ -590,6 +590,15 @@ And this is another one"
         Boolean Equals(UnSealedCustomEquals other);
     }
 
+    [default_interface]
+    [experimental]
+    runtimeclass CustomExperimentClass
+    {
+        CustomExperimentClass();
+        Int32 Value{ get; set; };
+        void f();
+    }
+
     // Compile time test for sub windows namespace
     namespace Windows
     {
diff --git a/src/Tests/TestComponentCSharp/TestComponentCSharp.vcxproj b/src/Tests/TestComponentCSharp/TestComponentCSharp.vcxproj
index d014d2c83..cbbd048ac 100644
--- a/src/Tests/TestComponentCSharp/TestComponentCSharp.vcxproj
+++ b/src/Tests/TestComponentCSharp/TestComponentCSharp.vcxproj
@@ -80,6 +80,7 @@
   <ItemGroup>
     <ClInclude Include="ABCDEFGHIJKLMNOPQRSTUVQXYZabcdefghijklmnopqrstuvqxyzABCDEFGHIJKLMNOPQRSTUVQXYZabcdefghijklmnopqrstuvqxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz.h" />
     <ClInclude Include="AnotherAssembly.SetPropertyClass.h" />
+    <ClInclude Include="CustomExperimentClass.h" />
     <ClInclude Include="CustomEquals.h" />
     <ClInclude Include="ManualProjectionTestClasses.h" />
     <ClInclude Include="pch.h" />
@@ -97,6 +98,7 @@
     <ClCompile Include="$(GeneratedFilesDir)module.g.cpp" />
     <ClCompile Include="ABCDEFGHIJKLMNOPQRSTUVQXYZabcdefghijklmnopqrstuvqxyzABCDEFGHIJKLMNOPQRSTUVQXYZabcdefghijklmnopqrstuvqxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz.cpp" />
     <ClCompile Include="AnotherAssembly.SetPropertyClass.cpp" />
+    <ClCompile Include="CustomExperimentClass.cpp" />
     <ClCompile Include="CustomEquals.cpp" />
     <ClCompile Include="pch.cpp">
       <PrecompiledHeader>Create</PrecompiledHeader>
diff --git a/src/Tests/TestComponentCSharp/TestComponentCSharp.vcxproj.filters b/src/Tests/TestComponentCSharp/TestComponentCSharp.vcxproj.filters
index e71b1a1c7..f87e12554 100644
--- a/src/Tests/TestComponentCSharp/TestComponentCSharp.vcxproj.filters
+++ b/src/Tests/TestComponentCSharp/TestComponentCSharp.vcxproj.filters
@@ -20,6 +20,7 @@
     <ClCompile Include="ABCDEFGHIJKLMNOPQRSTUVQXYZabcdefghijklmnopqrstuvqxyzABCDEFGHIJKLMNOPQRSTUVQXYZabcdefghijklmnopqrstuvqxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz.cpp" />
     <ClCompile Include="AnotherAssembly.SetPropertyClass.cpp" />
     <ClCompile Include="CustomEquals.cpp" />
+    <ClCompile Include="CustomExperimentClass.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="pch.h" />
@@ -33,6 +34,7 @@
     <ClInclude Include="ABCDEFGHIJKLMNOPQRSTUVQXYZabcdefghijklmnopqrstuvqxyzABCDEFGHIJKLMNOPQRSTUVQXYZabcdefghijklmnopqrstuvqxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz.h" />
     <ClInclude Include="AnotherAssembly.SetPropertyClass.h" />
     <ClInclude Include="CustomEquals.h" />
+    <ClInclude Include="CustomExperimentClass.h" />
   </ItemGroup>
   <ItemGroup>
     <Midl Include="TestComponentCSharp.idl" />
diff --git a/src/Tests/UnitTest/TestComponentCSharp_Tests.cs b/src/Tests/UnitTest/TestComponentCSharp_Tests.cs
index 2c21387e4..6badd330a 100644
--- a/src/Tests/UnitTest/TestComponentCSharp_Tests.cs
+++ b/src/Tests/UnitTest/TestComponentCSharp_Tests.cs
@@ -2905,5 +2905,12 @@ public void TestObjectFunctions()
             Assert.True(eighth.Equals(seventh));
             Assert.False(seventh.Equals(eighth));
         }
+
+        // Manually verify warning for experimental.
+        private void TestExperimentAttribute()
+        {
+            CustomExperimentClass custom = new CustomExperimentClass();
+            custom.f();
+        }
     }
 }
diff --git a/src/cswinrt/code_writers.h b/src/cswinrt/code_writers.h
index 5d8b5b025..26bc84faf 100644
--- a/src/cswinrt/code_writers.h
+++ b/src/cswinrt/code_writers.h
@@ -1697,7 +1697,8 @@ remove => %;
                     allow_multiple = true;
                 }
                 if (attribute_name != "DefaultOverload" && attribute_name != "Overload" && 
-                    attribute_name != "AttributeUsage" && attribute_name != "ContractVersion")
+                    attribute_name != "AttributeUsage" && attribute_name != "ContractVersion" &&
+                    attribute_name != "Experimental")
                 {
                     continue;
                 }