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 2.73GHz, 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 | 0.78.0 | 1.777 s | 0.0332 s | 0.0341 s | 1.765 s |
| Build_NUnit | 4.4.0 | 1.582 s | 0.0152 s | 0.0143 s | 1.577 s |
| Build_MSTest | 4.0.1 | 1.667 s | 0.0137 s | 0.0128 s | 1.668 s |
| Build_xUnit3 | 3.1.0 | 1.570 s | 0.0101 s | 0.0090 s | 1.569 s |
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 | 0.78.0 | 452.17 ms | 3.388 ms | 2.829 ms | 452.69 ms |
| NUnit | 4.4.0 | 565.57 ms | 9.621 ms | 8.528 ms | 567.10 ms |
| MSTest | 4.0.1 | 578.39 ms | 11.254 ms | 12.960 ms | 574.71 ms |
| xUnit3 | 3.1.0 | 522.50 ms | 4.072 ms | 3.610 ms | 522.72 ms |
| TUnit_AOT | 0.78.0 | 24.35 ms | 0.406 ms | 0.380 ms | 24.34 ms |
BenchmarkDotNet v0.15.4, Linux Ubuntu 24.04.3 LTS (Noble Numbat)
AMD EPYC 7763 3.23GHz, 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 | 0.78.0 | 497.97 ms | 9.414 ms | 10.073 ms | 496.53 ms |
| NUnit | 4.4.0 | 616.29 ms | 8.142 ms | 7.218 ms | 613.56 ms |
| MSTest | 4.0.1 | 631.89 ms | 8.377 ms | 6.995 ms | 630.92 ms |
| xUnit3 | 3.1.0 | 549.54 ms | 5.447 ms | 4.829 ms | 548.19 ms |
| TUnit_AOT | 0.78.0 | 24.02 ms | 0.201 ms | 0.157 ms | 24.04 ms |
BenchmarkDotNet v0.15.4, Linux Ubuntu 24.04.3 LTS (Noble Numbat)
Intel Xeon Platinum 8370C CPU 2.80GHz (Max: 2.62GHz), 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-v4
RyuJitX64 : .NET 10.0.0 (10.0.0-rc.2.25502.107, 10.0.25.50307), X64 RyuJIT x86-64-v4
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 | 0.78.0 | 439.78 ms | 3.590 ms | 2.998 ms | 440.24 ms |
| NUnit | 4.4.0 | 579.16 ms | 10.529 ms | 9.334 ms | 576.13 ms |
| MSTest | 4.0.1 | 592.15 ms | 11.068 ms | 9.242 ms | 592.37 ms |
| xUnit3 | 3.1.0 | 541.26 ms | 3.818 ms | 3.385 ms | 541.16 ms |
| TUnit_AOT | 0.78.0 | 29.11 ms | 0.289 ms | 0.256 ms | 29.09 ms |
BenchmarkDotNet v0.15.4, Linux Ubuntu 24.04.3 LTS (Noble Numbat)
AMD EPYC 7763 2.77GHz, 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 | 0.78.0 | 477.67 ms | 5.540 ms | 5.182 ms | 477.54 ms |
| NUnit | 4.4.0 | 603.24 ms | 9.112 ms | 7.609 ms | 603.63 ms |
| MSTest | 4.0.1 | 618.86 ms | 9.034 ms | 7.544 ms | 618.20 ms |
| xUnit3 | 3.1.0 | 541.77 ms | 4.720 ms | 4.184 ms | 542.61 ms |
| TUnit_AOT | 0.78.0 | 28.99 ms | 0.374 ms | 0.331 ms | 28.99 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 | 0.78.0 | 478.45 ms | 5.465 ms | 4.844 ms | 478.34 ms |
| NUnit | 4.4.0 | 585.18 ms | 10.662 ms | 10.471 ms | 583.94 ms |
| MSTest | 4.0.1 | 569.01 ms | 11.041 ms | 15.114 ms | 568.46 ms |
| xUnit3 | 3.1.0 | 508.09 ms | 5.421 ms | 4.806 ms | 508.19 ms |
| TUnit_AOT | 0.78.0 | 46.62 ms | 1.520 ms | 4.481 ms | 47.06 ms |