A .NET Testing Framework
$ dotnet add package TUnit
TUnit is a modern testing framework for .NET that uses source-generated tests, parallel execution by default, and Native AOT support. Built on Microsoft.Testing.Platform, it's faster than traditional reflection-based frameworks and gives you more control over how your tests run.
| Feature | Traditional Frameworks | TUnit |
|---|---|---|
| Test Discovery | ❌ Runtime reflection | ✅ Compile-time generation |
| Execution Speed | ❌ Sequential by default | ✅ Parallel by default |
| Modern .NET | ⚠️ Limited AOT support | ✅ Native AOT & trimming |
| Test Dependencies | ❌ Not supported | ✅ [DependsOn] chains |
| Resource Management | ❌ Manual lifecycle | ✅ Automatic cleanup |
Parallel by Default - Tests run concurrently with dependency management
Compile-Time Discovery - Test structure is known before runtime
Modern .NET Ready - Native AOT, trimming, and latest .NET features
Extensible - Customize data sources, attributes, and test behavior
New to TUnit? Start with the Getting Started Guide
Migrating? See the Migration Guides
Learn more: Data-Driven Testing, Test Dependencies, Parallelism Control
dotnet new install TUnit.Templates
dotnet new TUnit -n "MyTestProject"dotnet add package TUnit --prerelease|
Performance
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Test Control
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Data & Assertions
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Developer Tools
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[Test]
public async Task User_Creation_Should_Set_Timestamp()
{
// Arrange
var userService = new UserService();
// Act
var user = await userService.CreateUserAsync("john.doe@example.com");
// Assert - TUnit's fluent assertions
await Assert.That(user.CreatedAt)
.IsEqualTo(DateTime.Now)
.Within(TimeSpan.FromMinutes(1));
await Assert.That(user.Email)
.IsEqualTo("john.doe@example.com");
}[Test]
[Arguments("user1@test.com", "ValidPassword123")]
[Arguments("user2@test.com", "AnotherPassword456")]
[Arguments("admin@test.com", "AdminPass789")]
public async Task User_Login_Should_Succeed(string email, string password)
{
var result = await authService.LoginAsync(email, password);
await Assert.That(result.IsSuccess).IsTrue();
}
// Matrix testing - tests all combinations
[Test]
[MatrixDataSource]
public async Task Database_Operations_Work(
[Matrix("Create", "Update", "Delete")] string operation,
[Matrix("User", "Product", "Order")] string entity)
{
await Assert.That(await ExecuteOperation(operation, entity))
.IsTrue();
}[Before(Class)]
public static async Task SetupDatabase(ClassHookContext context)
{
await DatabaseHelper.InitializeAsync();
}
[Test, DisplayName("Register a new account")]
[MethodDataSource(nameof(GetTestUsers))]
public async Task Register_User(string username, string password)
{
// Test implementation
}
[Test, DependsOn(nameof(Register_User))]
[Retry(3)] // Retry on failure
public async Task Login_With_Registered_User(string username, string password)
{
// This test runs after Register_User completes
}
[Test]
[ParallelLimit<LoadTestParallelLimit>] // Custom parallel control
[Repeat(100)] // Run 100 times
public async Task Load_Test_Homepage()
{
// Performance testing
}
// Custom attributes
[Test, WindowsOnly, RetryOnHttpError(5)]
public async Task Windows_Specific_Feature()
{
// Platform-specific test with custom retry logic
}
public class LoadTestParallelLimit : IParallelLimit
{
public int Limit => 10; // Limit to 10 concurrent executions
}// Custom conditional execution
public class WindowsOnlyAttribute : SkipAttribute
{
public WindowsOnlyAttribute() : base("Windows only test") { }
public override Task<bool> ShouldSkip(TestContext testContext)
=> Task.FromResult(!OperatingSystem.IsWindows());
}
// Custom retry logic
public class RetryOnHttpErrorAttribute : RetryAttribute
{
public RetryOnHttpErrorAttribute(int times) : base(times) { }
public override Task<bool> ShouldRetry(TestInformation testInformation,
Exception exception, int currentRetryCount)
=> Task.FromResult(exception is HttpRequestException { StatusCode: HttpStatusCode.ServiceUnavailable });
}
Unit Testing[Test]
[Arguments(1, 2, 3)]
[Arguments(5, 10, 15)]
public async Task Calculate_Sum(int a, int b, int expected)
{
await Assert.That(Calculator.Add(a, b))
.IsEqualTo(expected);
}
|
Integration Testing[Test, DependsOn(nameof(CreateUser))]
public async Task Login_After_Registration()
{
// Runs after CreateUser completes
var result = await authService.Login(user);
await Assert.That(result.IsSuccess).IsTrue();
}
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Load Testing[Test]
[ParallelLimit<LoadTestLimit>]
[Repeat(1000)]
public async Task API_Handles_Concurrent_Requests()
{
await Assert.That(await httpClient.GetAsync("/api/health"))
.HasStatusCode(HttpStatusCode.OK);
}
|
Tests are discovered at build time, not runtime. This means faster discovery, better IDE integration, and more predictable resource management.
Tests run in parallel by default. Use [DependsOn] to chain tests together, and [ParallelLimit] to control resource usage.
The DataSourceGenerator<T> pattern and custom attribute system let you extend TUnit without modifying the framework.
TUnit works with all major .NET IDEs:
✅ Fully supported - No additional configuration needed for latest versions
⚙️ Earlier versions: Enable "Use testing platform server mode" in Tools > Manage Preview Features
✅ Fully supported
⚙️ Setup: Enable "Testing Platform support" in Settings > Build, Execution, Deployment > Unit Testing > Testing Platform
✅ Fully supported
⚙️ Setup: Install C# Dev Kit and enable "Use Testing Platform Protocol"
✅ Full CLI support - Works with dotnet test, dotnet run, and direct executable execution
| Package | Use Case |
|---|---|
TUnit | Start here - Complete testing framework (includes Core + Engine + Assertions) |
TUnit.Core | Test libraries and shared components (no execution engine) |
TUnit.Engine | Test execution engine and adapter (for test projects) |
TUnit.Assertions | Standalone assertions (works with any test framework) |
TUnit.Playwright | Playwright integration with automatic lifecycle management |
Coming from NUnit or xUnit? TUnit uses familiar syntax with some additions:
// TUnit test with dependency management and retries
[Test]
[Arguments("value1")]
[Arguments("value2")]
[Retry(3)]
[ParallelLimit<CustomLimit>]
public async Task Modern_TUnit_Test(string value) { }📖 Need help migrating? Check our Migration Guides for xUnit, NUnit, and MSTest.
The API is mostly stable, but may have some changes based on feedback before the v1.0 release.
# Create a new test project
dotnet new install TUnit.Templates && dotnet new TUnit -n "MyTestProject"
# Or add to existing project
dotnet add package TUnit --prerelease
Learn More: tunit.dev | Get Help: GitHub Discussions | Star on GitHub: github.com/thomhurst/TUnit
BenchmarkDotNet v0.15.4, Linux Ubuntu 24.04.3 LTS (Noble Numbat)
AMD EPYC 7763 2.45GHz, 1 CPU, 4 logical and 2 physical cores
.NET SDK 10.0.100-rc.2.25502.107
[Host] : .NET 10.0.0 (10.0.0-rc.2.25502.107, 10.0.25.50307), X64 RyuJIT x86-64-v3
RyuJitX64 : .NET 10.0.0 (10.0.0-rc.2.25502.107, 10.0.25.50307), X64 RyuJIT x86-64-v3
Job=RyuJitX64 Jit=RyuJit Platform=X64
PowerPlanMode=00000000-0000-0000-0000-000000000000 Runtime=.NET 10.0 Concurrent=True
Server=True
| Method | Version | Mean | Error | StdDev | Median |
|---|---|---|---|---|---|
| Build_TUnit | 0.77.3 | 1.781 s | 0.0327 s | 0.0306 s | 1.775 s |
| Build_NUnit | 4.4.0 | 1.567 s | 0.0224 s | 0.0199 s | 1.572 s |
| Build_MSTest | 4.0.1 | 1.653 s | 0.0255 s | 0.0226 s | 1.657 s |
| Build_xUnit3 | 3.1.0 | 1.569 s | 0.0135 s | 0.0126 s | 1.566 s |
BenchmarkDotNet v0.15.4, Linux Ubuntu 24.04.3 LTS (Noble Numbat)
AMD EPYC 7763 2.60GHz, 1 CPU, 4 logical and 2 physical cores
.NET SDK 10.0.100-rc.2.25502.107
[Host] : .NET 10.0.0 (10.0.0-rc.2.25502.107, 10.0.25.50307), X64 RyuJIT x86-64-v3
RyuJitX64 : .NET 10.0.0 (10.0.0-rc.2.25502.107, 10.0.25.50307), X64 RyuJIT x86-64-v3
Job=RyuJitX64 Jit=RyuJit Platform=X64
PowerPlanMode=00000000-0000-0000-0000-000000000000 Runtime=.NET 10.0 Concurrent=True
Server=True
| Method | Version | Mean | Error | StdDev | Median |
|---|---|---|---|---|---|
| TUnit | 0.77.3 | 478.94 ms | 5.325 ms | 4.981 ms | 479.13 ms |
| NUnit | 4.4.0 | 526.96 ms | 9.078 ms | 8.048 ms | 527.32 ms |
| MSTest | 4.0.1 | 503.03 ms | 9.642 ms | 12.872 ms | 499.80 ms |
| xUnit3 | 3.1.0 | 501.98 ms | 6.870 ms | 6.426 ms | 500.00 ms |
| TUnit_AOT | 0.77.3 | 34.13 ms | 0.487 ms | 0.406 ms | 33.97 ms |
BenchmarkDotNet v0.15.4, Linux Ubuntu 24.04.3 LTS (Noble Numbat)
AMD EPYC 7763 2.75GHz, 1 CPU, 4 logical and 2 physical cores
.NET SDK 10.0.100-rc.2.25502.107
[Host] : .NET 10.0.0 (10.0.0-rc.2.25502.107, 10.0.25.50307), X64 RyuJIT x86-64-v3
RyuJitX64 : .NET 10.0.0 (10.0.0-rc.2.25502.107, 10.0.25.50307), X64 RyuJIT x86-64-v3
Job=RyuJitX64 Jit=RyuJit Platform=X64
PowerPlanMode=00000000-0000-0000-0000-000000000000 Runtime=.NET 10.0 Concurrent=True
Server=True
| Method | Version | Mean | Error | StdDev | Median |
|---|---|---|---|---|---|
| TUnit | 0.77.3 | 485.31 ms | 3.767 ms | 3.524 ms | 484.81 ms |
| NUnit | 4.4.0 | 687.51 ms | 11.332 ms | 8.847 ms | 683.38 ms |
| MSTest | 4.0.1 | 689.18 ms | 8.267 ms | 7.329 ms | 688.63 ms |
| xUnit3 | 3.1.0 | 502.63 ms | 2.875 ms | 2.690 ms | 502.82 ms |
| TUnit_AOT | 0.77.3 | 34.64 ms | 0.688 ms | 1.995 ms | 34.20 ms |
BenchmarkDotNet v0.15.4, Linux Ubuntu 24.04.3 LTS (Noble Numbat)
AMD EPYC 7763 2.45GHz, 1 CPU, 4 logical and 2 physical cores
.NET SDK 10.0.100-rc.2.25502.107
[Host] : .NET 10.0.0 (10.0.0-rc.2.25502.107, 10.0.25.50307), X64 RyuJIT x86-64-v3
RyuJitX64 : .NET 10.0.0 (10.0.0-rc.2.25502.107, 10.0.25.50307), X64 RyuJIT x86-64-v3
Job=RyuJitX64 Jit=RyuJit Platform=X64
PowerPlanMode=00000000-0000-0000-0000-000000000000 Runtime=.NET 10.0 Concurrent=True
Server=True
| Method | Version | Mean | Error | StdDev | Median |
|---|---|---|---|---|---|
| TUnit | 0.77.3 | 499.03 ms | 6.589 ms | 5.841 ms | 498.34 ms |
| NUnit | 4.4.0 | 582.75 ms | 10.155 ms | 9.499 ms | 583.13 ms |
| MSTest | 4.0.1 | 560.42 ms | 8.550 ms | 7.997 ms | 560.16 ms |
| xUnit3 | 3.1.0 | 567.61 ms | 4.273 ms | 3.788 ms | 566.90 ms |
| TUnit_AOT | 0.77.3 | 39.00 ms | 0.255 ms | 0.238 ms | 39.04 ms |
BenchmarkDotNet v0.15.4, Linux Ubuntu 24.04.3 LTS (Noble Numbat)
AMD EPYC 7763 2.45GHz, 1 CPU, 4 logical and 2 physical cores
.NET SDK 10.0.100-rc.2.25502.107
[Host] : .NET 10.0.0 (10.0.0-rc.2.25502.107, 10.0.25.50307), X64 RyuJIT x86-64-v3
RyuJitX64 : .NET 10.0.0 (10.0.0-rc.2.25502.107, 10.0.25.50307), X64 RyuJIT x86-64-v3
Job=RyuJitX64 Jit=RyuJit Platform=X64
PowerPlanMode=00000000-0000-0000-0000-000000000000 Runtime=.NET 10.0 Concurrent=True
Server=True
| Method | Version | Mean | Error | StdDev | Median |
|---|---|---|---|---|---|
| TUnit | 0.77.3 | 509.47 ms | 6.776 ms | 6.007 ms | 508.85 ms |
| NUnit | 4.4.0 | 596.89 ms | 11.807 ms | 16.934 ms | 594.68 ms |
| MSTest | 4.0.1 | 610.32 ms | 11.764 ms | 11.004 ms | 613.12 ms |
| xUnit3 | 3.1.0 | 533.11 ms | 3.656 ms | 3.053 ms | 533.28 ms |
| TUnit_AOT | 0.77.3 | 37.61 ms | 0.499 ms | 0.467 ms | 37.68 ms |
BenchmarkDotNet v0.15.4, Linux Ubuntu 24.04.3 LTS (Noble Numbat)
AMD EPYC 7763 2.74GHz, 1 CPU, 4 logical and 2 physical cores
.NET SDK 10.0.100-rc.2.25502.107
[Host] : .NET 10.0.0 (10.0.0-rc.2.25502.107, 10.0.25.50307), X64 RyuJIT x86-64-v3
RyuJitX64 : .NET 10.0.0 (10.0.0-rc.2.25502.107, 10.0.25.50307), X64 RyuJIT x86-64-v3
Job=RyuJitX64 Jit=RyuJit Platform=X64
PowerPlanMode=00000000-0000-0000-0000-000000000000 Runtime=.NET 10.0 Concurrent=True
Server=True
| Method | Version | Mean | Error | StdDev | Median |
|---|---|---|---|---|---|
| TUnit | 0.77.3 | 507.33 ms | 5.869 ms | 5.490 ms | 509.06 ms |
| NUnit | 4.4.0 | 613.34 ms | 4.137 ms | 3.455 ms | 612.68 ms |
| MSTest | 4.0.1 | 632.89 ms | 11.515 ms | 10.208 ms | 635.09 ms |
| xUnit3 | 3.1.0 | 510.91 ms | 3.648 ms | 3.413 ms | 510.42 ms |
| TUnit_AOT | 0.77.3 | 56.39 ms | 1.220 ms | 3.597 ms | 56.85 ms |