Add project files.

test/Directory.Build.props

@@ -0,0 +1,24 @@
+<Project>
+
+  <Import Project="$([MSBuild]::GetPathOfFileAbove('Directory.Build.props', '$(MSBuildThisFileDirectory)../'))" />
+
+  <PropertyGroup>
+    <TargetFramework>net9.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+    <GenerateDocumentationFile>false</GenerateDocumentationFile>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="GitHubActionsTestLogger" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" />
+    <PackageReference Include="NSubstitute" />
+    <PackageReference Include="coverlet.collector" PrivateAssets="all" />
+    <PackageReference Include="xunit" />
+    <PackageReference Include="xunit.runner.visualstudio" PrivateAssets="all" />
+  </ItemGroup>
+
+</Project>