Nice3point.TUnit.Revit 2027.0.0

Testing Framework for Revit

Write unit tests for your Revit add-ins using the TUnit testing framework with source-generated tests, parallel execution, and Microsoft.Testing.Platform support.

Installation

You can install this library as a NuGet package.

The packages are compiled for specific versions of Revit. To support different versions of libraries in one project, use the RevitVersion property:

<PackageReference Include="Nice3point.TUnit.Revit" Version="$(RevitVersion).*"/>

Writing your first test

Start by creating a new class inheriting from RevitApiTest:

public class MyTestClass : RevitApiTest
{

}

Add a method with [Test] and [TestExecutor<RevitThreadExecutor>] attributes:

public class MyTestClass : RevitApiTest
{
    [Test]
    [TestExecutor<RevitThreadExecutor>]
    public async Task MyTest()
    {
        
    }
}

This is your runnable test. The [TestExecutor<RevitThreadExecutor>] attribute ensures the test executes within Revit's single-threaded API context.

Running your tests

TUnit is built on top of the Microsoft.Testing.Platform. Combined with source-generated tests, running your tests is available in multiple ways.

dotnet run

For simple project execution, dotnet run is the preferred method, allowing easier command line flag passing.

cd 'C:/Your/Test/Directory'
dotnet run -c "Release.R26"

dotnet test

dotnet test requires the configuration to target the desired Revit version.

cd 'C:/Your/Test/Directory'
dotnet test -c "Release.R26"

JetBrains Rider

The Enable Testing Platform support option must be selected in Settings > Build, Execution, Deployment > Unit Testing > Testing Platform.

Application testing

Test Revit application-level functionality using the Application property exposed by RevitApiTest:

public sealed class ApplicationTests : RevitApiTest
{
    [Test]
    [TestExecutor<RevitThreadExecutor>]
    public async Task Cities_BuiltinSet_IsNotEmpty()
    {
        var cities = Application.Cities.Cast<City>();

        await Assert.That(cities).IsNotEmpty();
    }

    [Test]
    [TestExecutor<RevitThreadExecutor>]
    public async Task Create_XYZ_ValidDistance()
    {
        var point = Application.Create.NewXYZ(3, 4, 5);

        await Assert.That(point.DistanceTo(XYZ.Zero)).IsEqualTo(7).Within(0.1);
    }
}

Document testing

Tests that pass alone but fail together are a classic sign of shared state. Give each test its own document — created in [Before(Test)], closed in [After(Test)] — and that problem disappears entirely. Use the setup hook to seed the document with exactly the state each test needs. The [HookExecutor<RevitThreadExecutor>] attribute ensures hooks also run on Revit's thread:

public sealed class ModelSeedTests : RevitApiTest
{
    private Document _document = null!;
    private IList<Wall> _exteriorWalls = null!;

    [Before(Test)]
    [HookExecutor<RevitThreadExecutor>]
    public void SeedModel()
    {
        _document = Application.NewProjectDocument(UnitSystem.Metric);

        using var transaction = new Transaction(_document, "Seed model");
        transaction.Start();

        _exteriorWalls =
        [
            Wall.Create(_document, Line.CreateBound(new XYZ(0, 0, 0), new XYZ(10, 0, 0)), level.Id, false),
            Wall.Create(_document, Line.CreateBound(new XYZ(10, 0, 0), new XYZ(10, 6, 0)), level.Id, false),
            Wall.Create(_document, Line.CreateBound(new XYZ(10, 6, 0), new XYZ(0, 6, 0)), level.Id, false),
            Wall.Create(_document, Line.CreateBound(new XYZ(0, 6, 0), new XYZ(0, 0, 0)), level.Id, false),
        ];

        transaction.Commit();
    }

    [After(Test)]
    [HookExecutor<RevitThreadExecutor>]
    public void CloseModel()
    {
        _document.Close(false);
    }

    [Test]
    [TestExecutor<RevitThreadExecutor>]
    public async Task FilteredElementCollector_ExteriorWalls_MatchSeededCount()
    {
        var walls = new FilteredElementCollector(_document)
            .WhereElementIsNotElementType()
            .OfClass(typeof(Wall))
            .ToList();

        await Assert.That(walls.Count).IsEqualTo(_exteriorWalls.Count);
    }

    [Test]
    [TestExecutor<RevitThreadExecutor>]
    public async Task Transaction_DemolishWall_RemainingWallCountDecreases()
    {
        var targetId = _exteriorWalls[0].Id;

        using var transaction = new Transaction(_document, "Demolish wall");
        transaction.Start();
        _document.Delete(targetId);
        transaction.Commit();

        var remainingWalls = new FilteredElementCollector(_document)
            .WhereElementIsNotElementType()
            .OfClass(typeof(Wall))
            .ToElementIds();

        await Assert.That(remainingWalls.Count).IsEqualTo(_exteriorWalls.Count - 1);
    }
}

More examples, including parametrized model and family tests, are available in the test project.

Test configuration

Global executor

To avoid repeating the TestExecutor attribute for every test, you can register the executor globally using one of the following methods:

• Add the attribute to any .cs file in your project (e.g., TestsConfiguration.cs):

  using Nice3point.TUnit.Revit.Executors;
  using TUnit.Core.Executors;
  
  [assembly: TestExecutor<RevitThreadExecutor>]
  

• Add the attribute directly to your .csproj file:

  
  <ItemGroup>
      <AssemblyAttribute Include="TUnit.Core.Executors.TestExecutorAttribute">
          <_Parameter1>typeof(Nice3point.TUnit.Revit.Executors.RevitThreadExecutor)</_Parameter1>
          <_Parameter1_IsLiteral>true</_Parameter1_IsLiteral>
      </AssemblyAttribute>
  </ItemGroup>
  

Revit Environment

TUnit initializes Revit with the English - United States language and the C:\Program Files\Autodesk\Revit {version} installation path. To override these defaults, use assembly-level attributes:

• Add the attributes to any .cs file in your project (e.g., TestsConfiguration.cs):

  using Nice3point.Revit.Injector.Attributes;
  
  [assembly: RevitLanguage("ENU")]
  [assembly: RevitInstallationPath("D:\Autodesk\Revit Preview")]
  

• Add the attributes directly to your .csproj file:

  
  <ItemGroup>
  
      <AssemblyAttribute Include="Nice3point.Revit.Injector.Attributes.RevitLanguageAttribute">
          <_Parameter1>ENU</_Parameter1>
      </AssemblyAttribute>
  
      <AssemblyAttribute Include="Nice3point.Revit.Injector.Attributes.RevitInstallationPathAttribute">
          <_Parameter1>D:\Autodesk\Revit $(RevitVersion)</_Parameter1>
      </AssemblyAttribute>
  
  </ItemGroup>
  

The RevitLanguage attribute accepts a language name (e.g., "English - United States"), code (e.g., "ENU") or LanguageType enum value (e.g., "English_GB" or "15").