TUnit

Run TUnit 1.72.10 tests inside a live Autodesk host through Microsoft Testing Platform and the DevTools.TestAdapter assembly. The adapter is the public NuGet package RevitDevTool.TestAdapter 0.1.2. Pin TUnit with Microsoft.Testing.Platform 2.4.1 (the adapter already depends on that MSBuild package; do not override it). The host lifecycle is the same as for NUnit; only the test framework and attributes differ.

Project setup

Configure MTP and replace NUnit with TUnit:

<PropertyGroup>
  <TestingFramework>tunit</TestingFramework>
  <HostName>Revit</HostName>
  <HostVersion>2025</HostVersion>
  <ForceLaunch>false</ForceLaunch>
  <PerTestTimeout>60</PerTestTimeout>
  <LaunchTimeout>360</LaunchTimeout>
</PropertyGroup>

<ItemGroup>
  <PackageReference Include="RevitDevTool.TestAdapter" Version="0.1.2" />
  <PackageReference Include="TUnit" Version="1.72.10" />
  <PackageReference Include="Revit_All_Main_Versions_API_x64" Version="2025.0.*"
    IncludeAssets="build; compile" PrivateAssets="All" />
</ItemGroup>

Create the MTP global.json beside the test .csproj:

{
  "sdk": { "version": "10.0.0", "rollForward": "latestMinor" },
  "test": { "runner": "Microsoft.Testing.Platform" }
}

Do not add VSTest adapters or a .runsettings file. Do not set <RuntimeIdentifier> on net8 / net10. On net48, set win-x64 only when the SDK requires it for an x64 executable.

TUnit's generated infrastructure uses [ModuleInitializer], which .NET Framework does not declare. The adapter compiles that attribute into net4x TUnit projects. It stands down when the project already references Polyfill or compiles its own ModuleInitializerAttribute.cs. Set <NetFxModuleInitializer>false</NetFxModuleInitializer> when that skip cannot see your type (a differently named file, PolySharp, or a polyfill package not named Polyfill). NUnit, MSTest, and net8 / net10 ignore the property. If the repo has a central GlobalPackageReference named Polyfill, remove it on the net48 TUnit project (NU1504 / CS0436).

Use the same project-level host settings as NUnit. HostName is Revit, AutoCad, Civil3D, Plant3D, AcadArch, AcadMech, AcadElec, AcadMep, or AcadMap3D.

Writing tests

Use TUnit's attributes and assertions. Tests still run in the Autodesk host, so keep host API access within the supported execution context and isolate document mutations carefully.

public class WallTests
{
    [Test]
    public async Task Active_document_is_available()
    {
        await Assert.That(Context.Document).IsNotNull();
    }
}

TUnit's async-first style is useful for tests that coordinate host operations, but it does not remove Revit transaction or UI-thread requirements.

Running and debugging

dotnet test --project .\MyHostTests.csproj -c Debug --filter Active_document

Run from the test project directory. Use --list-tests to inspect discovery and a method-name substring with --filter for a focused run. Attach a .NET debugger to the Autodesk host process before running the test when breakpoints are needed. See Attach Debugger.

Symptom	Check
TUnit tests are not discovered	Confirm <TestingFramework>tunit</TestingFramework> and the TUnit package
MTP starts but host calls fail	Verify host version, API references, and active document preconditions
Test hangs	Look for modal host UI or an unfinished transaction

See Testing Overview for shared lifecycle and pipe details.