only automatically generate projection for release config

UnitTest/Directory.Build.targets

@@ -2,6 +2,7 @@
 <Project ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
 
   <PropertyGroup>
+    <BuildTestProjection Condition="'$(BuildTestProjection)$(Configuration)' == 'Release'">true</BuildTestProjection>
     <RemoveWindowsReference>true</RemoveWindowsReference>
   </PropertyGroup>
 
@@ -10,7 +11,7 @@
     <Exec Command="xcopy /D /Y &quot;$(OutDir)TestComp\TestComp.pdb&quot; &quot;$(TargetDir)&quot;" />
   </Target>
 
-  <Target Name="ProjectTestComponent" BeforeTargets="CoreCompile">
+  <Target Name="ProjectTestComponent" BeforeTargets="CoreCompile" Condition="'$(BuildTestProjection)' == 'true'">
     <Exec Command="$(CsWinrtExe) -verbose -in $(OutDir)TestComp\TestComp.winmd local -out &quot;$(ProjectDir)Generated Files&quot; -include TestComp -include Windows.Foundation -exclude Windows.Foundation.Diagnostics -exclude Windows.Foundation.Metadata" />
     <ItemGroup>
       <Compile Include="$(ProjectDir)Generated Files/*.cs" Exclude="@(Compile)" />

WinUITest/Directory.Build.targets

@@ -2,10 +2,11 @@
 <Project ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   
   <PropertyGroup>
+    <BuildTestProjection Condition="'$(BuildTestProjection)$(Configuration)' == 'Release'">true</BuildTestProjection>
     <RemoveWindowsReference>true</RemoveWindowsReference>
   </PropertyGroup>
 
-  <Target Name="ProjectWinUI" BeforeTargets="CoreCompile">
+  <Target Name="ProjectWinUI" BeforeTargets="CoreCompile" Condition="'$(BuildTestProjection)' == 'true'">
     <ItemGroup>
       <!--PkgMicrosoft_UI_Xaml is defined by Nuget reference-->
       <WinUIWinMDs Include="$(PkgMicrosoft_UI_Xaml)/**/*.winmd" />

WinUITest/readme.txt

@@ -1,13 +1,13 @@
 This project simply generates and compiles a complete projection of Windows SDK and WinUI metadata.
 
 With a release cswinrt.exe, it takes < 1s to generate all of the projection sources.  
-With debug, it takes a minute.  With Test Explorer and other IDE features that
-implcitly invoke the compiler, this may interfere - will fiddle.
+With debug, it takes a minute.  So only release builds create the projection by default.  
+This can be overridden by explicitly setting the BuildTestProjection property.
 
 This project assumes a private nuget source has been created, pointing to:
 https://microsoft.pkgs.visualstudio.com/_packaging/WinUI-Xaml-CI@IXP/nuget/v3/index.json
 
-For usability (until the cswinrt nuget has msbulid support), this and the UnitTest projects
+For usability (until the cswinrt nuget has msbuild support), this and the UnitTest projects
 both make use of Directory.Build.* files to create the projection, stage binaries, etc.
 
 WinUITest uses a response file to generate the projection, which can be supplied as a

cswinrt.sln

@@ -14,6 +14,13 @@ Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "cswinrt", "cswinrt\cswinrt.
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WinUITest", "WinUITest\WinUITest.csproj", "{AD0BD44A-D9B5-419C-90D0-B017AEE09C85}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Build Files", "Build Files", "{96495AB4-2D86-47D1-A174-27D0B436DC98}"
+	ProjectSection(SolutionItems) = preProject
+		build.cmd = build.cmd
+		Directory.Build.props = Directory.Build.props
+		Directory.Build.targets = Directory.Build.targets
+	EndProjectSection
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU