Provide winrt_activation_handler to hook/mock activation (#477)

Author: kennykerr

strings/base_activation.h

@@ -21,6 +21,11 @@ namespace winrt::impl
     template <typename Interface>
     hresult get_runtime_activation_factory(param::hstring const& name, void** result) noexcept
     {
+        if (winrt_activation_handler)
+        {
+            return winrt_activation_handler(*(void**)(&name), guid_of<Interface>(), result);
+        }
+
         static int32_t(__stdcall * handler)(void* classId, guid const& iid, void** factory) noexcept;
 
         impl::load_runtime_function("RoGetActivationFactory", handler,

strings/base_extern.h

@@ -2,6 +2,7 @@
 __declspec(selectany) int32_t(__stdcall* winrt_to_hresult_handler)(void* address) noexcept {};
 __declspec(selectany) void(__stdcall* winrt_suspend_handler)(void const* token) noexcept {};
 __declspec(selectany) void(__stdcall* winrt_resume_handler)(void const* token) noexcept {};
+__declspec(selectany) int32_t(__stdcall* winrt_activation_handler)(void* classId, winrt::guid const& iid, void** factory) noexcept {};
 
 extern "C"
 {

test/test/custom_activation.cpp

@@ -0,0 +1,52 @@
+#include "winrt/Windows.Foundation.Numerics.h"
+#include "catch.hpp"
+
+using namespace winrt;
+using namespace Windows::Foundation;
+
+namespace
+{
+    struct custom_factory : implements<custom_factory, IUriRuntimeClassFactory>
+    {
+        inline static Uri mock_uri{ nullptr };
+
+        Uri CreateUri(hstring const& value) const
+        {
+            REQUIRE(value == L"http://ignored.com");
+            return mock_uri;
+        }
+
+        Uri CreateWithRelativeUri(hstring const&, hstring const&) const
+        {
+            throw hresult_not_implemented();
+        }
+    };
+
+    int32_t __stdcall handler(void* classId, winrt::guid const& iid, void** factory) noexcept
+    {
+        bool expected = reinterpret_cast<hstring const&>(classId) == L"Windows.Foundation.Uri";
+        REQUIRE(expected);
+        REQUIRE(iid == guid_of<IUriRuntimeClassFactory>());
+
+        *factory = detach_abi(make<custom_factory>());
+        return 0;
+    }
+}
+
+TEST_CASE("custom_activation")
+{
+    custom_factory::mock_uri = Uri(L"http://actual.com");
+    clear_factory_cache();
+
+    // Set up global handler
+    REQUIRE(!winrt_activation_handler);
+    winrt_activation_handler = handler;
+
+    // Windows.Foundation.Uri activation factory now returns mock object
+    auto uri = Uri(L"http://ignored.com");
+    REQUIRE(uri.Domain() == L"actual.com");
+
+    // Remove global handler
+    winrt_activation_handler = nullptr;
+    clear_factory_cache();
+}

test/test/test.vcxproj

@@ -315,6 +315,16 @@
       <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">NotUsing</PrecompiledHeader>
       <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Release|x64'">NotUsing</PrecompiledHeader>
     </ClCompile>
+    <ClCompile Include="custom_activation.cpp">
+      <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">NotUsing</PrecompiledHeader>
+      <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">NotUsing</PrecompiledHeader>
+      <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">NotUsing</PrecompiledHeader>
+      <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">NotUsing</PrecompiledHeader>
+      <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Debug|ARM'">NotUsing</PrecompiledHeader>
+      <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Release|ARM'">NotUsing</PrecompiledHeader>
+      <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">NotUsing</PrecompiledHeader>
+      <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Release|x64'">NotUsing</PrecompiledHeader>
+    </ClCompile>
     <ClCompile Include="custom_error.cpp" />
     <ClCompile Include="delegate.cpp" />
     <ClCompile Include="delegates.cpp" />