Update COM Activator class (#22317)

* Update COM Activator to use ALCs

* Update tests to now supply an assembly name rather than an binary "path"
  since the COM activator is now using ALCs.

* Add test for non-rooted assembly path.

* Move the hostpolicy mock project to a Common area
Move hostpolicy mock API to CoreCLR test library

* Add test for COM server isolation

* Move ComActivator class and logic to Internal namespace.

29 files changed, 360 insertions, 57 deletions

diff --git a/tests/src/Common/CoreCLRTestLibrary/CoreCLRTestLibrary.csproj b/tests/src/Common/CoreCLRTestLibrary/CoreCLRTestLibrary.csproj
index 7e210d0749..ea0ee84166 100644
--- a/tests/src/Common/CoreCLRTestLibrary/CoreCLRTestLibrary.csproj
+++ b/tests/src/Common/CoreCLRTestLibrary/CoreCLRTestLibrary.csproj
@@ -31,9 +31,8 @@
     <Compile Include="Logging.cs" />
     <Compile Include="TestFramework.cs" />
     <Compile Include="Utilities.cs" />
-  </ItemGroup>
-  <ItemGroup>
-    <Service Include="{82A7F48D-3B50-4B1E-B82E-3ADA8210C358}" />
+    <Compile Include="HostPolicyMock.cs" />
+    <Compile Include="XPlatformUtils.cs" />
   </ItemGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
 </Project>
diff --git a/tests/src/Loader/AssemblyDependencyResolverTests/HostPolicyMock.cs b/tests/src/Common/CoreCLRTestLibrary/HostPolicyMock.cs
index 37cedbc542..afa1fbcd0d 100644
--- a/tests/src/Loader/AssemblyDependencyResolverTests/HostPolicyMock.cs
+++ b/tests/src/Common/CoreCLRTestLibrary/HostPolicyMock.cs
@@ -6,15 +6,15 @@ using System.IO;
 using System.Runtime.InteropServices;
 using System.Runtime.Loader;
 
-namespace AssemblyDependencyResolverTests
+namespace TestLibrary
 {
-    class HostPolicyMock
+    public class HostPolicyMock
     {
-#if WINDOWS
+    #if PLATFORM_WINDOWS
         private const CharSet HostpolicyCharSet = CharSet.Unicode;
-#else
+    #else
         private const CharSet HostpolicyCharSet = CharSet.Ansi;
-#endif
+    #endif
 
         [DllImport("hostpolicy", CharSet = HostpolicyCharSet)]
         private static extern int Set_corehost_resolve_component_dependencies_Values(
@@ -45,24 +45,32 @@ namespace AssemblyDependencyResolverTests
 
         public static string DeleteExistingHostpolicy(string coreRoot)
         {
+#if REFERENCING_SYSTEMPRIVATECORELIB
+            throw new Exception("This API is not supported when compiled referencing SPCL");
+
+#else
             string hostPolicyFileName = XPlatformUtils.GetStandardNativeLibraryFileName("hostpolicy");
             string destinationPath = Path.Combine(coreRoot, hostPolicyFileName);
+
             if (File.Exists(destinationPath))
             {
                 File.Delete(destinationPath);
             }
 
             return destinationPath;
+#endif
         }
 
         public static void Initialize(string testBasePath, string coreRoot)
         {
+#if !REFERENCING_SYSTEMPRIVATECORELIB
             string hostPolicyFileName = XPlatformUtils.GetStandardNativeLibraryFileName("hostpolicy");
             string destinationPath = DeleteExistingHostpolicy(coreRoot);
 
             File.Copy(
                 Path.Combine(testBasePath, hostPolicyFileName),
                 destinationPath);
+#endif
 
             _assemblyDependencyResolverType = typeof(AssemblyDependencyResolver);
 
@@ -72,7 +80,7 @@ namespace AssemblyDependencyResolverTests
             _corehost_error_writer_fnType = _assemblyDependencyResolverType.GetNestedType("corehost_error_writer_fn", System.Reflection.BindingFlags.NonPublic);
         }
 
-        public static MockValues_corehost_resolve_componet_dependencies Mock_corehost_resolve_componet_dependencies(
+        public static MockValues_corehost_resolve_component_dependencies Mock_corehost_resolve_component_dependencies(
             int returnValue,
             string assemblyPaths,
             string nativeSearchPaths,
@@ -84,10 +92,10 @@ namespace AssemblyDependencyResolverTests
                 nativeSearchPaths,
                 resourceSearchPaths);
 
-            return new MockValues_corehost_resolve_componet_dependencies();
+            return new MockValues_corehost_resolve_component_dependencies();
         }
 
-        internal class MockValues_corehost_resolve_componet_dependencies : IDisposable
+        public class MockValues_corehost_resolve_component_dependencies : IDisposable
         {
             private Callback_corehost_resolve_component_dependencies callback;
 
@@ -133,7 +141,7 @@ namespace AssemblyDependencyResolverTests
             return new MockValues_corehost_set_error_writer();
         }
 
-        internal class MockValues_corehost_set_error_writer : IDisposable
+        public class MockValues_corehost_set_error_writer : IDisposable
         {
             public IntPtr LastSetErrorWriterPtr
             {
diff --git a/tests/src/Loader/AssemblyDependencyResolverTests/XPlatformUtils.cs b/tests/src/Common/CoreCLRTestLibrary/XPlatformUtils.cs
index fd931f465d..e8bcca27eb 100644
--- a/tests/src/Loader/AssemblyDependencyResolverTests/XPlatformUtils.cs
+++ b/tests/src/Common/CoreCLRTestLibrary/XPlatformUtils.cs
@@ -1,16 +1,17 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
-namespace AssemblyDependencyResolverTests
+
+namespace TestLibrary
 {
-    class XPlatformUtils
+    public class XPlatformUtils
     {
-#if WINDOWS
+#if PLATFORM_WINDOWS
         public const string NativeLibraryPrefix = "";
         public const string NativeLibrarySuffix = ".dll";
 #else
         public const string NativeLibraryPrefix = "lib";
-#if OSX
+#if PLATFORM_OSX
         public const string NativeLibrarySuffix = ".dylib";
 #else
         public const string NativeLibrarySuffix = ".so";
diff --git a/tests/src/Loader/AssemblyDependencyResolverTests/CMakeLists.txt b/tests/src/Common/hostpolicymock/CMakeLists.txt
index 9e4821148b..9e4821148b 100644
--- a/tests/src/Loader/AssemblyDependencyResolverTests/CMakeLists.txt
+++ b/tests/src/Common/hostpolicymock/CMakeLists.txt
diff --git a/tests/src/Loader/AssemblyDependencyResolverTests/HostpolicyMock.cpp b/tests/src/Common/hostpolicymock/HostpolicyMock.cpp
index b1a90d2af3..cd16afa1a0 100644
--- a/tests/src/Loader/AssemblyDependencyResolverTests/HostpolicyMock.cpp
+++ b/tests/src/Common/hostpolicymock/HostpolicyMock.cpp
@@ -14,7 +14,17 @@
 typedef wchar_t char_t;
 typedef std::wstring string_t;
 
-#else //!_Win32
+// Only create undecorated exports on Windows x86
+#if defined _X86_
+
+// Define undecorated exports to ease test set up from native code
+#pragma comment(linker, "/export:Set_corehost_resolve_component_dependencies_Callback=_Set_corehost_resolve_component_dependencies_Callback@4")
+#pragma comment(linker, "/export:Set_corehost_resolve_component_dependencies_Values=_Set_corehost_resolve_component_dependencies_Values@16")
+#pragma comment(linker, "/export:Set_corehost_set_error_writer_returnValue=_Set_corehost_set_error_writer_returnValue@4")
+
+#endif
+
+#else //!_WIN32
 
 #if __GNUC__ >= 4
 #define SHARED_API extern "C" __attribute__ ((visibility ("default")))
diff --git a/tests/src/Interop/COM/Activator/Activator.csproj b/tests/src/Interop/COM/Activator/Activator.csproj
index 792b8be2fe..b656a5c1e9 100644
--- a/tests/src/Interop/COM/Activator/Activator.csproj
+++ b/tests/src/Interop/COM/Activator/Activator.csproj
@@ -1,7 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
-  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), Interop.settings.targets))\Interop.settings.targets" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
@@ -14,6 +13,8 @@
     <TestUnsupportedOutsideWindows>true</TestUnsupportedOutsideWindows>
     <DisableProjectBuild Condition="'$(TargetsWindows)' != 'true'">true</DisableProjectBuild>
   </PropertyGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), Interop.settings.targets))\Interop.settings.targets" />
+
   <!-- Default configurations to help VS understand the configurations -->
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x64'">
   </PropertyGroup>
@@ -24,6 +25,30 @@
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\NetServer\NetServer.csproj" />
+    <ProjectReference Include="Servers\AssemblyA.csproj" />
+    <ProjectReference Include="Servers\AssemblyB.csproj" />
+    <ProjectReference Include="Servers\AssemblyC.csproj" />
+    <ProjectReference Include="Servers\AssemblyContracts.csproj" />
+    <ProjectReference Include="../../../Common/hostpolicymock/CMakeLists.txt" />
   </ItemGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
+
+  <!-- Set up an isolated directory for the server assemblies -->
+  <Target Name="SetUpIsolatedDirectory"
+          AfterTargets="CopyFilesToOutputDirectory">
+
+    <PropertyGroup>
+      <ServerAssemblyDest>$(OutDir)/Servers</ServerAssemblyDest>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <ServerAssembly Include="$(OutDir)/AssemblyA.*" />
+      <ServerAssembly Include="$(OutDir)/AssemblyB.*" />
+      <ServerAssembly Include="$(OutDir)/AssemblyC.*" />
+    </ItemGroup>
+
+    <Move SourceFiles="@(ServerAssembly)"
+          DestinationFolder="$(ServerAssemblyDest)" />
+  </Target>
+
 </Project>
diff --git a/tests/src/Interop/COM/Activator/Program.cs b/tests/src/Interop/COM/Activator/Program.cs
index 4316736950..451ecc7755 100644
--- a/tests/src/Interop/COM/Activator/Program.cs
+++ b/tests/src/Interop/COM/Activator/Program.cs
@@ -4,7 +4,10 @@
 
 namespace Activator
 {
+    using Internal.Runtime.InteropServices;
+
     using System;
+    using System.IO;
     using System.Runtime.InteropServices;
 
     using TestLibrary;
@@ -15,6 +18,8 @@ namespace Activator
     {
         static void InvalidInterfaceRequest()
         {
+            Console.WriteLine($"Running {nameof(InvalidInterfaceRequest)}...");
+
             Assert.Throws<NotSupportedException>(
                 () =>
                 {
@@ -28,17 +33,36 @@ namespace Activator
                 "Non-IClassFactory request should fail");
         }
 
+        static void NonrootedAssemblyPath()
+        {
+            Console.WriteLine($"Running {nameof(NonrootedAssemblyPath)}...");
+
+            ArgumentException e = Assert.Throws<ArgumentException>(
+                () =>
+                {
+                    var cxt = new ComActivationContext()
+                    {
+                        InterfaceId = typeof(IClassFactory).GUID,
+                        AssemblyPath = "foo.dll"
+                    };
+                    ComActivator.GetClassFactoryForType(cxt);
+                },
+                "Non-root assembly path should not be valid");
+        }
+
         static void ClassNotRegistered()
         {
+            Console.WriteLine($"Running {nameof(ClassNotRegistered)}...");
+
             COMException e = Assert.Throws<COMException>(
                 () =>
                 {
                     var CLSID_NotRegistered = new Guid("328FF83E-3F6C-4BE9-A742-752562032925"); // Random GUID
-                    var IID_IClassFactory = new Guid("00000001-0000-0000-C000-000000000046");
                     var cxt = new ComActivationContext()
                     {
                         ClassId = CLSID_NotRegistered,
-                        InterfaceId = IID_IClassFactory
+                        InterfaceId = typeof(IClassFactory).GUID,
+                        AssemblyPath = @"C:\foo.dll"
                     };
                     ComActivator.GetClassFactoryForType(cxt);
                 },
@@ -48,12 +72,78 @@ namespace Activator
             Assert.AreEqual(CLASS_E_CLASSNOTAVAILABLE, e.HResult, "Unexpected HRESULT");
         }
 
+        static void ValidateAssemblyIsolation()
+        {
+            Console.WriteLine($"Running {nameof(ValidateAssemblyIsolation)}...");
+
+            string assemblySubPath = Path.Combine(Environment.CurrentDirectory, "Servers");
+            string assemblyAPath = Path.Combine(assemblySubPath, "AssemblyA.dll");
+            string assemblyBPath = Path.Combine(assemblySubPath, "AssemblyB.dll");
+            string assemblyCPath = Path.Combine(assemblySubPath, "AssemblyC.dll");
+            string assemblyPaths = $"{assemblyAPath}{Path.PathSeparator}{assemblyBPath}{Path.PathSeparator}{assemblyCPath}";
+
+            HostPolicyMock.Initialize(Environment.CurrentDirectory, null);
+
+            var CLSID_NotUsed = Guid.Empty; // During this phase of activation the GUID is not used.
+            Guid iid = typeof(IGetTypeFromC).GUID;
+            Type typeCFromAssemblyA;
+            Type typeCFromAssemblyB;
+
+            using (HostPolicyMock.Mock_corehost_resolve_component_dependencies(
+                0,
+                assemblyPaths,
+                string.Empty,
+                string.Empty))
+            {
+                var cxt = new ComActivationContext()
+                {
+                    ClassId = CLSID_NotUsed,
+                    InterfaceId = typeof(IClassFactory).GUID,
+                    AssemblyPath = assemblyAPath,
+                    AssemblyName = "AssemblyA",
+                    TypeName = "ClassFromA"
+                };
+
+                var factory = (IClassFactory)ComActivator.GetClassFactoryForType(cxt);
+
+                object svr;
+                factory.CreateInstance(null, ref iid, out svr);
+                typeCFromAssemblyA = (Type)((IGetTypeFromC)svr).GetTypeFromC();
+            }
+
+            using (HostPolicyMock.Mock_corehost_resolve_component_dependencies(
+                0,
+                assemblyPaths,
+                string.Empty,
+                string.Empty))
+            {
+                var cxt = new ComActivationContext()
+                {
+                    ClassId = CLSID_NotUsed,
+                    InterfaceId = typeof(IClassFactory).GUID,
+                    AssemblyPath = assemblyBPath,
+                    AssemblyName = "AssemblyB",
+                    TypeName = "ClassFromB"
+                };
+
+                var factory = (IClassFactory)ComActivator.GetClassFactoryForType(cxt);
+
+                object svr;
+                factory.CreateInstance(null, ref iid, out svr);
+                typeCFromAssemblyB = (Type)((IGetTypeFromC)svr).GetTypeFromC();
+            }
+
+            Assert.AreNotEqual(typeCFromAssemblyA, typeCFromAssemblyB, "Types should be from different AssemblyLoadContexts");
+        }
+
         static int Main(string[] doNotUse)
         {
             try
             {
                 InvalidInterfaceRequest();
                 ClassNotRegistered();
+                NonrootedAssemblyPath();
+                ValidateAssemblyIsolation();
             }
             catch (Exception e)
             {
diff --git a/tests/src/Interop/COM/Activator/Servers/AssemblyA.cs b/tests/src/Interop/COM/Activator/Servers/AssemblyA.cs
new file mode 100644
index 0000000000..606f064c92
--- /dev/null
+++ b/tests/src/Interop/COM/Activator/Servers/AssemblyA.cs
@@ -0,0 +1,19 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+
+public class ClassFromA : IGetTypeFromC
+{
+    private readonly ClassFromC _fromC;
+    public ClassFromA()
+    {
+        this._fromC = new ClassFromC();
+    }
+    
+    public object GetTypeFromC()
+    {
+        return this._fromC.GetType();
+    }
+}
\ No newline at end of file
diff --git a/tests/src/Interop/COM/Activator/Servers/AssemblyA.csproj b/tests/src/Interop/COM/Activator/Servers/AssemblyA.csproj
new file mode 100644
index 0000000000..b5fbf3b4ad
--- /dev/null
+++ b/tests/src/Interop/COM/Activator/Servers/AssemblyA.csproj
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), Interop.settings.targets))\Interop.settings.targets" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <AssemblyName>AssemblyA</AssemblyName>
+    <SchemaVersion>2.0</SchemaVersion>
+    <OutputType>library</OutputType>
+    <ProjectTypeGuids>{4948E98A-ECFC-4988-851E-68E1ADD2DD5A};{B850CC46-E8FB-4569-A28D-423F81E8A861}</ProjectTypeGuids>
+  </PropertyGroup>
+  <!-- Default configurations to help VS understand the configurations -->
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x64'">
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x64'">
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="AssemblyA.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="AssemblyC.csproj" />
+    <ProjectReference Include="AssemblyContracts.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
+</Project>
diff --git a/tests/src/Interop/COM/Activator/Servers/AssemblyB.cs b/tests/src/Interop/COM/Activator/Servers/AssemblyB.cs
new file mode 100644
index 0000000000..043434d033
--- /dev/null
+++ b/tests/src/Interop/COM/Activator/Servers/AssemblyB.cs
@@ -0,0 +1,19 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+
+public class ClassFromB : IGetTypeFromC
+{
+    private readonly ClassFromC _fromC;
+    public ClassFromB()
+    {
+        this._fromC = new ClassFromC();
+    }
+    
+    public object GetTypeFromC()
+    {
+        return this._fromC.GetType();
+    }
+}
\ No newline at end of file
diff --git a/tests/src/Interop/COM/Activator/Servers/AssemblyB.csproj b/tests/src/Interop/COM/Activator/Servers/AssemblyB.csproj
new file mode 100644
index 0000000000..8f0fb0af8e
--- /dev/null
+++ b/tests/src/Interop/COM/Activator/Servers/AssemblyB.csproj
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), Interop.settings.targets))\Interop.settings.targets" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <AssemblyName>AssemblyB</AssemblyName>
+    <SchemaVersion>2.0</SchemaVersion>
+    <OutputType>library</OutputType>
+    <ProjectTypeGuids>{4948E98A-ECFC-4988-851E-68E1ADD2DD5A};{B850CC46-E8FB-4569-A28D-423F81E8A861}</ProjectTypeGuids>
+  </PropertyGroup>
+  <!-- Default configurations to help VS understand the configurations -->
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x64'">
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x64'">
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="AssemblyB.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="AssemblyC.csproj" />
+    <ProjectReference Include="AssemblyContracts.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
+</Project>
diff --git a/tests/src/Interop/COM/Activator/Servers/AssemblyC.cs b/tests/src/Interop/COM/Activator/Servers/AssemblyC.cs
new file mode 100644
index 0000000000..fbb79f65f4
--- /dev/null
+++ b/tests/src/Interop/COM/Activator/Servers/AssemblyC.cs
@@ -0,0 +1,9 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+
+public class ClassFromC
+{
+}
\ No newline at end of file
diff --git a/tests/src/Interop/COM/Activator/Servers/AssemblyC.csproj b/tests/src/Interop/COM/Activator/Servers/AssemblyC.csproj
new file mode 100644
index 0000000000..8c5a84ca5f
--- /dev/null
+++ b/tests/src/Interop/COM/Activator/Servers/AssemblyC.csproj
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), Interop.settings.targets))\Interop.settings.targets" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <AssemblyName>AssemblyC</AssemblyName>
+    <SchemaVersion>2.0</SchemaVersion>
+    <OutputType>library</OutputType>
+    <ProjectTypeGuids>{4948E98A-ECFC-4988-851E-68E1ADD2DD5A};{B850CC46-E8FB-4569-A28D-423F81E8A861}</ProjectTypeGuids>
+  </PropertyGroup>
+  <!-- Default configurations to help VS understand the configurations -->
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x64'">
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x64'">
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="AssemblyC.cs" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
+</Project>
diff --git a/tests/src/Interop/COM/Activator/Servers/AssemblyContracts.cs b/tests/src/Interop/COM/Activator/Servers/AssemblyContracts.cs
new file mode 100644
index 0000000000..deb7b6312b
--- /dev/null
+++ b/tests/src/Interop/COM/Activator/Servers/AssemblyContracts.cs
@@ -0,0 +1,13 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.IO;
+using System.Runtime.InteropServices;
+
+[Guid("6B002803-4C9B-4E4F-BDA2-46AEFFD8D559")]
+public interface IGetTypeFromC
+{
+    object GetTypeFromC();
+}
\ No newline at end of file
diff --git a/tests/src/Interop/COM/Activator/Servers/AssemblyContracts.csproj b/tests/src/Interop/COM/Activator/Servers/AssemblyContracts.csproj
new file mode 100644
index 0000000000..40cd185e4d
--- /dev/null
+++ b/tests/src/Interop/COM/Activator/Servers/AssemblyContracts.csproj
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), Interop.settings.targets))\Interop.settings.targets" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <AssemblyName>AssemblyContracts</AssemblyName>
+    <SchemaVersion>2.0</SchemaVersion>
+    <OutputType>library</OutputType>
+    <ProjectTypeGuids>{4948E98A-ECFC-4988-851E-68E1ADD2DD5A};{B850CC46-E8FB-4569-A28D-423F81E8A861}</ProjectTypeGuids>
+  </PropertyGroup>
+  <!-- Default configurations to help VS understand the configurations -->
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x64'">
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x64'">
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="AssemblyContracts.cs" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
+</Project>
diff --git a/tests/src/Interop/COM/NativeClients/Primitives.csproj b/tests/src/Interop/COM/NativeClients/Primitives.csproj
index 2aa9343ffd..305f1048b3 100644
--- a/tests/src/Interop/COM/NativeClients/Primitives.csproj
+++ b/tests/src/Interop/COM/NativeClients/Primitives.csproj
@@ -14,8 +14,9 @@
     <Compile Include="$(InteropCommonDir)ExeLauncherProgram.cs" />
   </ItemGroup>
   <ItemGroup>
-    <ProjectReference Include="Primitives/CMakeLists.txt"/>
+    <ProjectReference Include="Primitives/CMakeLists.txt" />
     <ProjectReference Include="../NetServer/NetServer.csproj" />
+    <ProjectReference Include="../../../Common/hostpolicymock/CMakeLists.txt" />
     <ProjectReference Include="../../../Common/CoreCLRTestLibrary/CoreCLRTestLibrary.csproj" />
   </ItemGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
diff --git a/tests/src/Interop/COM/NativeClients/Primitives/ArrayTests.cpp b/tests/src/Interop/COM/NativeClients/Primitives/ArrayTests.cpp
index 1bbdc10ad8..2e57bb9127 100644
--- a/tests/src/Interop/COM/NativeClients/Primitives/ArrayTests.cpp
+++ b/tests/src/Interop/COM/NativeClients/Primitives/ArrayTests.cpp
@@ -299,7 +299,7 @@ void Run_ArrayTests()
 {
     HRESULT hr;
 
-    CoreShimComActivation csact{ W("NETServer.dll"), W("ArrayTesting") };
+    CoreShimComActivation csact{ W("NETServer"), W("ArrayTesting") };
 
     ComSmartPtr<IArrayTesting> arrayTesting;
     THROW_IF_FAILED(::CoCreateInstance(CLSID_ArrayTesting, nullptr, CLSCTX_INPROC, IID_IArrayTesting, (void**)&arrayTesting));
diff --git a/tests/src/Interop/COM/NativeClients/Primitives/ColorTests.cpp b/tests/src/Interop/COM/NativeClients/Primitives/ColorTests.cpp
index ab95740e43..9ce8a8010c 100644
--- a/tests/src/Interop/COM/NativeClients/Primitives/ColorTests.cpp
+++ b/tests/src/Interop/COM/NativeClients/Primitives/ColorTests.cpp
@@ -34,7 +34,7 @@ void Run_ColorTests()
 {
     HRESULT hr;
 
-    CoreShimComActivation csact{ W("NETServer.dll"), W("ColorTesting") };
+    CoreShimComActivation csact{ W("NETServer"), W("ColorTesting") };
 
     ComSmartPtr<IColorTesting> color;
     THROW_IF_FAILED(::CoCreateInstance(CLSID_ColorTesting, nullptr, CLSCTX_INPROC, IID_IColorTesting, (void**)&color));
diff --git a/tests/src/Interop/COM/NativeClients/Primitives/ErrorTests.cpp b/tests/src/Interop/COM/NativeClients/Primitives/ErrorTests.cpp
index 7e40716ce9..1708aca2e1 100644
--- a/tests/src/Interop/COM/NativeClients/Primitives/ErrorTests.cpp
+++ b/tests/src/Interop/COM/NativeClients/Primitives/ErrorTests.cpp
@@ -58,7 +58,7 @@ void Run_ErrorTests()
 {
     HRESULT hr;
 
-    CoreShimComActivation csact{ W("NETServer.dll"), W("ErrorMarshalTesting") };
+    CoreShimComActivation csact{ W("NETServer"), W("ErrorMarshalTesting") };
 
     ComSmartPtr<IErrorMarshalTesting> errorMarshal;
     THROW_IF_FAILED(::CoCreateInstance(CLSID_ErrorMarshalTesting, nullptr, CLSCTX_INPROC, IID_IErrorMarshalTesting, (void**)&errorMarshal));
diff --git a/tests/src/Interop/COM/NativeClients/Primitives/NumericTests.cpp b/tests/src/Interop/COM/NativeClients/Primitives/NumericTests.cpp
index a9af9569de..c951c8c527 100644
--- a/tests/src/Interop/COM/NativeClients/Primitives/NumericTests.cpp
+++ b/tests/src/Interop/COM/NativeClients/Primitives/NumericTests.cpp
@@ -222,7 +222,7 @@ void Run_NumericTests()
 {
     HRESULT hr;
 
-    CoreShimComActivation csact{ W("NETServer.dll"), W("NumericTesting") };
+    CoreShimComActivation csact{ W("NETServer"), W("NumericTesting") };
 
     ComSmartPtr<INumericTesting> numericTesting;
     THROW_IF_FAILED(::CoCreateInstance(CLSID_NumericTesting, nullptr, CLSCTX_INPROC, IID_INumericTesting, (void**)&numericTesting));
diff --git a/tests/src/Interop/COM/NativeClients/Primitives/StringTests.cpp b/tests/src/Interop/COM/NativeClients/Primitives/StringTests.cpp
index 96a713faff..b003130d48 100644
--- a/tests/src/Interop/COM/NativeClients/Primitives/StringTests.cpp
+++ b/tests/src/Interop/COM/NativeClients/Primitives/StringTests.cpp
@@ -412,7 +412,7 @@ void Run_StringTests()
 {
     HRESULT hr;
 
-    CoreShimComActivation csact{ W("NETServer.dll"), W("StringTesting") };
+    CoreShimComActivation csact{ W("NETServer"), W("StringTesting") };
 
     ComSmartPtr<IStringTesting> stringTesting;
     THROW_IF_FAILED(::CoCreateInstance(CLSID_StringTesting, nullptr, CLSCTX_INPROC, IID_IStringTesting, (void**)&stringTesting));
diff --git a/tests/src/Interop/ExecInDefAppDom/ExecInDefAppDom.csproj b/tests/src/Interop/ExecInDefAppDom/ExecInDefAppDom.csproj
index 5f170492fb..7725f2f830 100644
--- a/tests/src/Interop/ExecInDefAppDom/ExecInDefAppDom.csproj
+++ b/tests/src/Interop/ExecInDefAppDom/ExecInDefAppDom.csproj
@@ -1,7 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
-  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), Interop.settings.targets))\Interop.settings.targets" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
@@ -14,6 +13,8 @@
     <DefineConstants>$(DefineConstants);STATIC</DefineConstants>
     <ReferenceSystemPrivateCoreLib>true</ReferenceSystemPrivateCoreLib>
   </PropertyGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), Interop.settings.targets))\Interop.settings.targets" />
+
   <!-- Default configurations to help VS understand the configurations -->
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x64'"></PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x64'"></PropertyGroup>
diff --git a/tests/src/Interop/Interop.settings.targets b/tests/src/Interop/Interop.settings.targets
index e16b1300b7..fc906f200d 100644
--- a/tests/src/Interop/Interop.settings.targets
+++ b/tests/src/Interop/Interop.settings.targets
@@ -6,16 +6,22 @@
 
   <!-- Environment properties -->
   <PropertyGroup>
+    <DefineConstants Condition="'$(ReferenceSystemPrivateCoreLib)' == 'true'">$(DefineConstants);REFERENCING_SYSTEMPRIVATECORELIB</DefineConstants>
   </PropertyGroup>
 
-  <!-- Required source files -->
-  <ItemGroup>
-    <ProjectReference 
-      Condition="('$(IgnoreCoreCLRTestLibraryDependency)' != 'true') And ('$(ReferenceSystemPrivateCoreLib)' != 'true')" 
+  <!-- Add the CoreCLRTestLibrary dependency -->
+  <ItemGroup Condition="('$(IgnoreCoreCLRTestLibraryDependency)' != 'true') And ('$(ReferenceSystemPrivateCoreLib)' != 'true')">
+    <ProjectReference
       Include="$(MSBuildThisFileDirectory)\..\Common\CoreCLRTestLibrary\CoreCLRTestLibrary.csproj" />
-    <Compile
-      Condition="('$(IgnoreCoreCLRTestLibraryDependency)' != 'true') And ('$(ReferenceSystemPrivateCoreLib)' == 'true')"
-      Include="$(MSBuildThisFileDirectory)\..\Common\CoreCLRTestLibrary\Assertion.cs" />
+  </ItemGroup>
+
+  <!-- Add the CoreCLRTestLibrary dependency
+       If a target project references System.Private.Corelib, we are unable to reference CoreCLRTestLibrary.
+       Compile in relevant files used for testing interop. -->
+  <ItemGroup Condition="('$(IgnoreCoreCLRTestLibraryDependency)' != 'true') And ('$(ReferenceSystemPrivateCoreLib)' == 'true')">
+    <Compile Include="$(MSBuildThisFileDirectory)\..\Common\CoreCLRTestLibrary\Assertion.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)\..\Common\CoreCLRTestLibrary\HostPolicyMock.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)\..\Common\CoreCLRTestLibrary\XPlatformUtils.cs" />
   </ItemGroup>
 
   <!-- Required debug vcruntime and UCRT dlls -->
diff --git a/tests/src/Interop/NativeCallable/NativeCallableTest.csproj b/tests/src/Interop/NativeCallable/NativeCallableTest.csproj
index 689e1244f1..59cbe9dc06 100644
--- a/tests/src/Interop/NativeCallable/NativeCallableTest.csproj
+++ b/tests/src/Interop/NativeCallable/NativeCallableTest.csproj
@@ -1,7 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
-  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), Interop.settings.targets))\Interop.settings.targets" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
@@ -15,6 +14,8 @@
     <ReferenceSystemPrivateCoreLib>true</ReferenceSystemPrivateCoreLib>
     <CLRTestPriority>1</CLRTestPriority>
   </PropertyGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), Interop.settings.targets))\Interop.settings.targets" />
+
   <!-- Default configurations to help VS understand the configurations -->
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x64'"></PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x64'"></PropertyGroup>
diff --git a/tests/src/Interop/PInvoke/CustomMarshalers/CustomMarshalersTest.csproj b/tests/src/Interop/PInvoke/CustomMarshalers/CustomMarshalersTest.csproj
index f92a77879f..dd3ac5e21e 100644
--- a/tests/src/Interop/PInvoke/CustomMarshalers/CustomMarshalersTest.csproj
+++ b/tests/src/Interop/PInvoke/CustomMarshalers/CustomMarshalersTest.csproj
@@ -1,7 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
-  <Import Project="../../Interop.settings.targets" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
@@ -19,6 +18,8 @@
     <TestUnsupportedOutsideWindows>true</TestUnsupportedOutsideWindows>
     <DisableProjectBuild Condition="'$(TargetsUnix)' == 'true'">true</DisableProjectBuild>
   </PropertyGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), Interop.settings.targets))\Interop.settings.targets" />
+
   <!-- Default configurations to help VS understand the configurations -->
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x64'"></PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x64'"></PropertyGroup>
diff --git a/tests/src/Loader/AssemblyDependencyResolverTests/AssemblyDependencyResolverTests.cs b/tests/src/Loader/AssemblyDependencyResolverTests/AssemblyDependencyResolverTests.cs
index 9499bee724..3e74a6627d 100644
--- a/tests/src/Loader/AssemblyDependencyResolverTests/AssemblyDependencyResolverTests.cs
+++ b/tests/src/Loader/AssemblyDependencyResolverTests/AssemblyDependencyResolverTests.cs
@@ -5,8 +5,11 @@ using System;
 using System.IO;
 using System.Reflection;
 using System.Runtime.Loader;
+using TestLibrary;
 using Xunit;
 
+using Assert = Xunit.Assert;
+
 namespace AssemblyDependencyResolverTests
 {
     class AssemblyDependencyResolverTests : TestBase
@@ -38,8 +41,8 @@ namespace AssemblyDependencyResolverTests
             using (HostPolicyMock.MockValues_corehost_set_error_writer errorWriterMock = 
                 HostPolicyMock.Mock_corehost_set_error_writer())
             {
-                using (HostPolicyMock.MockValues_corehost_resolve_componet_dependencies resolverMock = 
-                    HostPolicyMock.Mock_corehost_resolve_componet_dependencies(
+                using (HostPolicyMock.MockValues_corehost_resolve_component_dependencies resolverMock = 
+                    HostPolicyMock.Mock_corehost_resolve_component_dependencies(
                         134,
                         "",
                         "",
@@ -79,8 +82,8 @@ namespace AssemblyDependencyResolverTests
             using (HostPolicyMock.MockValues_corehost_set_error_writer errorWriterMock =
                 HostPolicyMock.Mock_corehost_set_error_writer(previousWriter))
             {
-                using (HostPolicyMock.MockValues_corehost_resolve_componet_dependencies resolverMock =
-                    HostPolicyMock.Mock_corehost_resolve_componet_dependencies(
+                using (HostPolicyMock.MockValues_corehost_resolve_component_dependencies resolverMock =
+                    HostPolicyMock.Mock_corehost_resolve_component_dependencies(
                         134,
                         "",
                         "",
@@ -108,7 +111,7 @@ namespace AssemblyDependencyResolverTests
             using (HostPolicyMock.MockValues_corehost_set_error_writer errorWriterMock =
                 HostPolicyMock.Mock_corehost_set_error_writer(previousWriter))
             {
-                using (HostPolicyMock.Mock_corehost_resolve_componet_dependencies(
+                using (HostPolicyMock.Mock_corehost_resolve_component_dependencies(
                     0,
                     assemblyDependencyPath,
                     "",
@@ -131,7 +134,7 @@ namespace AssemblyDependencyResolverTests
         {
             // If the reqest is for assembly which is not listed in .deps.json
             // the resolver should return null.
-            using (HostPolicyMock.Mock_corehost_resolve_componet_dependencies(
+            using (HostPolicyMock.Mock_corehost_resolve_component_dependencies(
                 0,
                 "",
                 "",
@@ -148,7 +151,7 @@ namespace AssemblyDependencyResolverTests
         {
             // Even if the .deps.json can resolve the request, if the file is not present
             // the resolution should still return null.
-            using (HostPolicyMock.Mock_corehost_resolve_componet_dependencies(
+            using (HostPolicyMock.Mock_corehost_resolve_component_dependencies(
                 0,
                 Path.Combine(_componentDirectory, "NonExistingAssembly.dll"),
                 "",
@@ -164,7 +167,7 @@ namespace AssemblyDependencyResolverTests
         public void TestSingleResource()
         {
             string enResourcePath = CreateMockAssembly($"en{Path.DirectorySeparatorChar}TestComponent.resources.dll");
-            using (HostPolicyMock.Mock_corehost_resolve_componet_dependencies(
+            using (HostPolicyMock.Mock_corehost_resolve_component_dependencies(
                 0,
                 "",
                 "",
@@ -183,7 +186,7 @@ namespace AssemblyDependencyResolverTests
         {
             string enResourcePath = CreateMockAssembly($"en{Path.DirectorySeparatorChar}TestComponent.resources.dll");
             string csResourcePath = CreateMockAssembly($"cs{Path.DirectorySeparatorChar}TestComponent.resources.dll");
-            using (HostPolicyMock.Mock_corehost_resolve_componet_dependencies(
+            using (HostPolicyMock.Mock_corehost_resolve_component_dependencies(
                 0,
                 "",
                 "",
@@ -205,7 +208,7 @@ namespace AssemblyDependencyResolverTests
         {
             string enResourcePath = CreateMockAssembly($"en{Path.DirectorySeparatorChar}TestComponent.resources.dll");
             string frResourcePath = CreateMockAssembly($"SubComponent{Path.DirectorySeparatorChar}fr{Path.DirectorySeparatorChar}TestComponent.resources.dll");
-            using (HostPolicyMock.Mock_corehost_resolve_componet_dependencies(
+            using (HostPolicyMock.Mock_corehost_resolve_component_dependencies(
                 0,
                 "",
                 "",
@@ -226,7 +229,7 @@ namespace AssemblyDependencyResolverTests
         public void TestAssemblyWithNeutralCulture()
         {
             string neutralAssemblyPath = CreateMockAssembly("NeutralAssembly.dll");
-            using (HostPolicyMock.Mock_corehost_resolve_componet_dependencies(
+            using (HostPolicyMock.Mock_corehost_resolve_component_dependencies(
                 0,
                 neutralAssemblyPath,
                 "",
@@ -245,7 +248,7 @@ namespace AssemblyDependencyResolverTests
         {
             string nativeLibraryPath = CreateMockStandardNativeLibrary("native", "Single");
 
-            using (HostPolicyMock.Mock_corehost_resolve_componet_dependencies(
+            using (HostPolicyMock.Mock_corehost_resolve_component_dependencies(
                 0,
                 "",
                 Path.GetDirectoryName(nativeLibraryPath),
@@ -265,7 +268,7 @@ namespace AssemblyDependencyResolverTests
             string oneNativeLibraryPath = CreateMockStandardNativeLibrary($"native{Path.DirectorySeparatorChar}one", "One");
             string twoNativeLibraryPath = CreateMockStandardNativeLibrary($"native{Path.DirectorySeparatorChar}two", "Two");
 
-            using (HostPolicyMock.Mock_corehost_resolve_componet_dependencies(
+            using (HostPolicyMock.Mock_corehost_resolve_component_dependencies(
                 0,
                 "",
                 $"{Path.GetDirectoryName(oneNativeLibraryPath)}{Path.PathSeparator}{Path.GetDirectoryName(twoNativeLibraryPath)}",
diff --git a/tests/src/Loader/AssemblyDependencyResolverTests/AssemblyDependencyResolverTests.csproj b/tests/src/Loader/AssemblyDependencyResolverTests/AssemblyDependencyResolverTests.csproj
index c8ba654dcf..e2dd0a4df3 100644
--- a/tests/src/Loader/AssemblyDependencyResolverTests/AssemblyDependencyResolverTests.csproj
+++ b/tests/src/Loader/AssemblyDependencyResolverTests/AssemblyDependencyResolverTests.csproj
@@ -11,20 +11,15 @@
     <!-- The test fails if ran twice in the same process. In one of the test cases, it expects a hostpolicy to not to be found, but it actually is found in the second pass -->
     <UnloadabilityIncompatible>true</UnloadabilityIncompatible>
   </PropertyGroup>
-  <PropertyGroup>
-    <DefineConstants Condition="$(OSGroup) == 'Windows_NT'">WINDOWS</DefineConstants>
-    <DefineConstants Condition="$(OSGroup) == 'OSX'">OSX</DefineConstants>
-  </PropertyGroup>
   <ItemGroup>
     <Compile Include="AssemblyDependencyResolverTests.cs" />
-    <Compile Include="HostPolicyMock.cs" />
     <Compile Include="InvalidHostingTest.cs" />
     <Compile Include="NativeDependencyTests.cs" />
     <Compile Include="TestBase.cs" />
-    <Compile Include="XPlatformUtils.cs" />
   </ItemGroup>
   <ItemGroup>
-    <ProjectReference Include="CMakeLists.txt" />
+    <ProjectReference Include="../../Common/CoreCLRTestLibrary/CoreCLRTestLibrary.csproj" />
+    <ProjectReference Include="../../Common/hostpolicymock/CMakeLists.txt" />
   </ItemGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
 </Project>
diff --git a/tests/src/Loader/AssemblyDependencyResolverTests/InvalidHostingTest.cs b/tests/src/Loader/AssemblyDependencyResolverTests/InvalidHostingTest.cs
index c51b055e07..d1fc56ecf4 100644
--- a/tests/src/Loader/AssemblyDependencyResolverTests/InvalidHostingTest.cs
+++ b/tests/src/Loader/AssemblyDependencyResolverTests/InvalidHostingTest.cs
@@ -4,8 +4,11 @@
 using System;
 using System.IO;
 using System.Runtime.Loader;
+using TestLibrary;
 using Xunit;
 
+using Assert = Xunit.Assert;
+
 namespace AssemblyDependencyResolverTests
 {
     class InvalidHostingTest : TestBase
diff --git a/tests/src/Loader/AssemblyDependencyResolverTests/NativeDependencyTests.cs b/tests/src/Loader/AssemblyDependencyResolverTests/NativeDependencyTests.cs
index 43e721e45f..e7ac906e02 100644
--- a/tests/src/Loader/AssemblyDependencyResolverTests/NativeDependencyTests.cs
+++ b/tests/src/Loader/AssemblyDependencyResolverTests/NativeDependencyTests.cs
@@ -5,8 +5,11 @@ using System;
 using System.IO;
 using System.Runtime.InteropServices;
 using System.Runtime.Loader;
+using TestLibrary;
 using Xunit;
 
+using Assert = Xunit.Assert;
+
 namespace AssemblyDependencyResolverTests
 {
     class NativeDependencyTests : TestBase
@@ -258,7 +261,7 @@ namespace AssemblyDependencyResolverTests
             string lookupName,
             OS resolvesOnOSes)
         {
-            using (HostPolicyMock.Mock_corehost_resolve_componet_dependencies(
+            using (HostPolicyMock.Mock_corehost_resolve_component_dependencies(
                 0,
                 "",
                 $"{nativeLibraryPaths}",