TUnit.Assertions.FSharp 0.25.21

🚀 The Modern Testing Framework for .NET

TUnit is a next-generation testing framework for C# that outpaces traditional frameworks with source-generated tests, parallel execution by default, and Native AOT support. Built on the modern Microsoft.Testing.Platform, TUnit delivers faster test runs, better developer experience, and unmatched flexibility.

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⚡ Why Choose TUnit?

Feature	Traditional Frameworks	TUnit
Test Discovery	❌ Runtime reflection	✅ Compile-time generation
Execution Speed	❌ Sequential by default	✅ Parallel by default
Modern .NET	⚠️ Limited AOT support	✅ Full Native AOT & trimming
Test Dependencies	❌ Not supported	✅ [DependsOn] chains
Resource Management	❌ Manual lifecycle	✅ Intelligent cleanup

⚡ Parallel by Default - Tests run concurrently with intelligent dependency management

🎯 Compile-Time Discovery - Know your test structure before runtime

🔧 Modern .NET Ready - Native AOT, trimming, and latest .NET features

🎭 Extensible - Customize data sources, attributes, and test behavior

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📚 Complete Documentation & Learning Center

🚀 New to TUnit? Start with our Getting Started Guide

🔄 Migrating? See our Migration Guides

🎯 Advanced Features? Explore Data-Driven Testing, Test Dependencies, and Parallelism Control

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🏁 Quick Start

Using the Project Template (Recommended)

dotnet new install TUnit.Templates
dotnet new TUnit -n "MyTestProject"

Manual Installation

dotnet add package TUnit --prerelease

📖 📚 Complete Documentation & Guides - Everything you need to master TUnit

✨ Key Features

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🚀 Performance & Modern Platform

• 🔥 Source-generated tests (no reflection)
• ⚡ Parallel execution by default
• 🚀 Native AOT & trimming support
• 📈 Optimized for performance

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🎯 Advanced Test Control

• 🔗 Test dependencies with [DependsOn]
• 🎛️ Parallel limits & custom scheduling
• 🛡️ Built-in analyzers & compile-time checks
• 🎭 Custom attributes & extensible conditions

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📊 Rich Data & Assertions

• 📋 Multiple data sources ([Arguments], [Matrix], [ClassData])
• ✅ Fluent async assertions
• 🔄 Smart retry logic & conditional execution
• 📝 Rich test metadata & context

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🔧 Developer Experience

• 💉 Full dependency injection support
• 🪝 Comprehensive lifecycle hooks
• 🎯 IDE integration (VS, Rider, VS Code)
• 📚 Extensive documentation & examples

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📝 Simple Test Example

[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");
}

🎯 Data-Driven Testing

[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();
}

🔗 Advanced Test Orchestration

[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
}

🔧 Smart Test Control

// 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 });
}

🎯 Perfect For Every Testing Scenario

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🧪 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);
}

Fast, isolated, and reliable

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🔗 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();
}

Stateful workflows made simple

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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);
}

Built-in performance testing

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🚀 What Makes TUnit Different?

Compile-Time Intelligence

Tests are discovered at build time, not runtime - enabling faster discovery, better IDE integration, and precise resource lifecycle management.

Parallel-First Architecture

Built for concurrency from day one with [DependsOn] for test chains, [ParallelLimit] for resource control, and intelligent scheduling.

Extensible by Design

The DataSourceGenerator<T> pattern and custom attribute system let you extend TUnit's capabilities without modifying core framework code.

🏆 Community & Ecosystem

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🌟 Join thousands of developers modernizing their testing

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🤝 Active Community

• 📚 Official Documentation - Comprehensive guides, tutorials, and API reference
• 💬 GitHub Discussions - Get help and share ideas
• 🐛 Issue Tracking - Report bugs and request features
• 📢 Release Notes - Stay updated with latest improvements

🛠️ IDE Support

TUnit works seamlessly across all major .NET development environments:

Visual Studio (2022 17.13+)

✅ Fully supported - No additional configuration needed for latest versions

⚙️ Earlier versions: Enable "Use testing platform server mode" in Tools > Manage Preview Features

JetBrains Rider

✅ Fully supported

⚙️ Setup: Enable "Testing Platform support" in Settings > Build, Execution, Deployment > Unit Testing > VSTest

Visual Studio Code

✅ Fully supported

⚙️ Setup: Install C# Dev Kit and enable "Use Testing Platform Protocol"

Command Line

✅ Full CLI support - Works with dotnet test, dotnet run, and direct executable execution

📦 Package Options

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

🎯 Migration from Other Frameworks

Coming from NUnit or xUnit? TUnit maintains familiar syntax while adding modern capabilities:

// Enhanced with TUnit's advanced features
[Test]
[Arguments("value1")]
[Arguments("value2")]
[Retry(3)]
[ParallelLimit<CustomLimit>]
public async Task Modern_TUnit_Test(string value) { }

📖 Need help migrating? Check our detailed Migration Guides with step-by-step instructions for xUnit, NUnit, and MSTest.

💡 Current Status

The API is mostly stable, but may have some changes based on feedback or issues before v1.0 release.

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🚀 Ready to Experience the Future of .NET Testing?

⚡ Start in 30 Seconds

# Create a new test project with examples
dotnet new install TUnit.Templates && dotnet new TUnit -n "MyAwesomeTests"

# Or add to existing project
dotnet add package TUnit --prerelease

🎯 Why Wait? Join the Movement

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📈 Performance

Optimized execution Parallel by default Zero reflection overhead

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🔮 Future-Ready

Native AOT support Latest .NET features Source generation

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🛠️ Developer Experience

Compile-time checks Rich IDE integration Intelligent debugging

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🎭 Flexibility

Test dependencies Custom attributes Extensible architecture

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📖 Learn More: tunit.dev | 💬 Get Help: GitHub Discussions | ⭐ Show Support: Star on GitHub

TUnit is actively developed and production-ready. Join our growing community of developers who've made the switch!

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Performance Benchmark

Scenario: Building the test project

macos-latest

BenchmarkDotNet v0.15.1, macOS Sonoma 14.7.6 (23H626) [Darwin 23.6.0]
Apple M1 (Virtual), 1 CPU, 3 logical and 3 physical cores
.NET SDK 9.0.300
  [Host]   : .NET 9.0.5 (9.0.525.21509), Arm64 RyuJIT AdvSIMD
  .NET 9.0 : .NET 9.0.5 (9.0.525.21509), Arm64 RyuJIT AdvSIMD

Job=.NET 9.0  Runtime=.NET 9.0  

Method	Mean	Error	StdDev	Median
Build_TUnit	1,095.9 ms	55.61 ms	160.46 ms	1,033.7 ms
Build_NUnit	839.2 ms	16.76 ms	25.09 ms	838.6 ms
Build_xUnit	809.8 ms	15.37 ms	22.53 ms	808.3 ms
Build_MSTest	810.8 ms	16.01 ms	38.04 ms	792.5 ms

ubuntu-latest

BenchmarkDotNet v0.15.1, Linux Ubuntu 24.04.2 LTS (Noble Numbat)
AMD EPYC 7763, 1 CPU, 4 logical and 2 physical cores
.NET SDK 9.0.300
  [Host]   : .NET 9.0.5 (9.0.525.21509), X64 RyuJIT AVX2
  .NET 9.0 : .NET 9.0.5 (9.0.525.21509), X64 RyuJIT AVX2

Job=.NET 9.0  Runtime=.NET 9.0  

Method	Mean	Error	StdDev
Build_TUnit	1.882 s	0.0363 s	0.0544 s
Build_NUnit	1.468 s	0.0227 s	0.0212 s
Build_xUnit	1.469 s	0.0290 s	0.0415 s
Build_MSTest	1.476 s	0.0292 s	0.0312 s

windows-latest

BenchmarkDotNet v0.15.1, Windows 10 (10.0.20348.3561) (Hyper-V)
AMD EPYC 7763 2.44GHz, 1 CPU, 4 logical and 2 physical cores
.NET SDK 9.0.300
  [Host]   : .NET 9.0.5 (9.0.525.21509), X64 RyuJIT AVX2
  .NET 9.0 : .NET 9.0.5 (9.0.525.21509), X64 RyuJIT AVX2

Job=.NET 9.0  Runtime=.NET 9.0  

Method	Mean	Error	StdDev
Build_TUnit	1.934 s	0.0378 s	0.0652 s
Build_NUnit	1.512 s	0.0116 s	0.0097 s
Build_xUnit	1.492 s	0.0173 s	0.0162 s
Build_MSTest	1.539 s	0.0167 s	0.0157 s

Scenario: A single test that completes instantly (including spawning a new process and initialising the test framework)

macos-latest

BenchmarkDotNet v0.15.1, macOS Sonoma 14.7.6 (23H626) [Darwin 23.6.0]
Apple M1 (Virtual), 1 CPU, 3 logical and 3 physical cores
.NET SDK 9.0.300
  [Host]   : .NET 9.0.5 (9.0.525.21509), Arm64 RyuJIT AdvSIMD
  .NET 9.0 : .NET 9.0.5 (9.0.525.21509), Arm64 RyuJIT AdvSIMD

Job=.NET 9.0  Runtime=.NET 9.0  

Method	Mean	Error	StdDev	Median
TUnit_AOT	70.87 ms	1.358 ms	1.718 ms	70.50 ms
TUnit	483.73 ms	9.135 ms	16.704 ms	478.81 ms
NUnit	721.73 ms	14.373 ms	37.612 ms	704.97 ms
xUnit	728.46 ms	10.863 ms	10.668 ms	729.08 ms
MSTest	619.42 ms	8.239 ms	7.304 ms	617.74 ms

ubuntu-latest

BenchmarkDotNet v0.15.1, Linux Ubuntu 24.04.2 LTS (Noble Numbat)
AMD EPYC 7763, 1 CPU, 4 logical and 2 physical cores
.NET SDK 9.0.300
  [Host]   : .NET 9.0.5 (9.0.525.21509), X64 RyuJIT AVX2
  .NET 9.0 : .NET 9.0.5 (9.0.525.21509), X64 RyuJIT AVX2

Job=.NET 9.0  Runtime=.NET 9.0  

Method	Mean	Error	StdDev
TUnit_AOT	27.94 ms	0.584 ms	1.713 ms
TUnit	837.56 ms	16.433 ms	20.783 ms
NUnit	1,314.99 ms	17.786 ms	16.637 ms
xUnit	1,381.22 ms	14.792 ms	13.113 ms
MSTest	1,176.63 ms	23.003 ms	21.517 ms

windows-latest

BenchmarkDotNet v0.15.1, Windows 10 (10.0.20348.3561) (Hyper-V)
AMD EPYC 7763 2.44GHz, 1 CPU, 4 logical and 2 physical cores
.NET SDK 9.0.300
  [Host]   : .NET 9.0.5 (9.0.525.21509), X64 RyuJIT AVX2
  .NET 9.0 : .NET 9.0.5 (9.0.525.21509), X64 RyuJIT AVX2

Job=.NET 9.0  Runtime=.NET 9.0  

Method	Mean	Error	StdDev
TUnit_AOT	58.50 ms	1.780 ms	5.250 ms
TUnit	865.35 ms	17.209 ms	25.225 ms
NUnit	1,288.20 ms	10.914 ms	10.209 ms
xUnit	1,328.49 ms	14.863 ms	13.903 ms
MSTest	1,141.89 ms	9.761 ms	8.653 ms

Scenario: A test that takes 50ms to execute, repeated 100 times (including spawning a new process and initialising the test framework)

macos-latest

BenchmarkDotNet v0.15.1, macOS Sonoma 14.7.6 (23H626) [Darwin 23.6.0]
Apple M1 (Virtual), 1 CPU, 3 logical and 3 physical cores
.NET SDK 9.0.300
  [Host]   : .NET 9.0.5 (9.0.525.21509), Arm64 RyuJIT AdvSIMD
  .NET 9.0 : .NET 9.0.5 (9.0.525.21509), Arm64 RyuJIT AdvSIMD

Job=.NET 9.0  Runtime=.NET 9.0  

Method	Mean	Error	StdDev
TUnit_AOT	243.3 ms	14.80 ms	43.65 ms
TUnit	683.3 ms	23.02 ms	67.88 ms
NUnit	14,069.9 ms	279.44 ms	545.03 ms
xUnit	14,244.1 ms	284.06 ms	416.37 ms
MSTest	14,242.6 ms	282.94 ms	502.93 ms

ubuntu-latest

BenchmarkDotNet v0.15.1, Linux Ubuntu 24.04.2 LTS (Noble Numbat)
AMD EPYC 7763, 1 CPU, 4 logical and 2 physical cores
.NET SDK 9.0.300
  [Host]   : .NET 9.0.5 (9.0.525.21509), X64 RyuJIT AVX2
  .NET 9.0 : .NET 9.0.5 (9.0.525.21509), X64 RyuJIT AVX2

Job=.NET 9.0  Runtime=.NET 9.0  

Method	Mean	Error	StdDev
TUnit_AOT	74.83 ms	1.459 ms	1.622 ms
TUnit	891.96 ms	17.616 ms	24.695 ms
NUnit	6,261.05 ms	10.030 ms	8.892 ms
xUnit	6,408.39 ms	7.017 ms	6.564 ms
MSTest	6,229.08 ms	13.224 ms	11.723 ms

windows-latest

BenchmarkDotNet v0.15.1, Windows 10 (10.0.20348.3695) (Hyper-V)
AMD EPYC 7763 2.44GHz, 1 CPU, 4 logical and 2 physical cores
.NET SDK 9.0.300
  [Host]   : .NET 9.0.5 (9.0.525.21509), X64 RyuJIT AVX2
  .NET 9.0 : .NET 9.0.5 (9.0.525.21509), X64 RyuJIT AVX2

Job=.NET 9.0  Runtime=.NET 9.0  

Method	Mean	Error	StdDev
TUnit_AOT	111.5 ms	2.23 ms	1.86 ms
TUnit	947.5 ms	18.94 ms	25.29 ms
NUnit	7,488.4 ms	13.25 ms	11.06 ms
xUnit	7,553.0 ms	11.64 ms	9.09 ms
MSTest	7,442.2 ms	43.09 ms	40.31 ms