NextUnit 1.18.0

NextUnit - Modern Testing for .NET 10+

NextUnit is a modern, high-performance test framework for .NET 10+ that combines:

• TUnit's modern architecture - Microsoft.Testing.Platform, Native AOT, source generators
• xUnit's familiar assertions - Classic Assert.Equal(expected, actual), no fluent syntax

Quick Start

Installation

Simple - One Package (Recommended):

dotnet add package NextUnit

This meta-package includes everything you need:

• NextUnit.Core - Attributes, assertions, execution engine
• NextUnit.Platform - Microsoft.Testing.Platform integration
• NextUnit.Generator - Source generator for zero-reflection discovery
• NextUnit.Analyzers - Compile-time validation
• Microsoft.Testing.Platform.MSBuild - dotnet test, dotnet run, and IDE entry point generation
• Microsoft.Testing.Extensions.TrxReport - CI-friendly TRX result files

Configure Your Test Project

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net10.0</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="NextUnit" Version="1.18.0" />
  </ItemGroup>
</Project>

Note: No OutputType=Exe, Program.cs, or separate analyzer reference is needed. The package configures Microsoft.Testing.Platform and registers NextUnit automatically.

Write Your First Test

using NextUnit;

public class CalculatorTests
{
    [Test]
    public void Add_TwoNumbers_ReturnsSum()
    {
        var result = 2 + 2;
        Assert.Equal(4, result);
    }

    [Test]
    [Arguments(1, 2, 3)]
    [Arguments(5, 5, 10)]
    public void Add_Parameterized(int a, int b, int expected)
    {
        Assert.Equal(expected, a + b);
    }
}

Run Tests

dotnet run --project MyProject.Tests

To run an entire repository with dotnet test on the .NET 10 SDK, select Microsoft.Testing.Platform in the repository's global.json:

{
  "test": {
    "runner": "Microsoft.Testing.Platform"
  }
}

Key Features

• Zero-reflection execution - Fast test discovery via source generators
• Rich assertions - Collections, strings, numerics, reference identity, and tolerance comparisons
• Async tests - Task, Task<T>, ValueTask, and ValueTask<T> return types for tests and lifecycle hooks
• Test artifacts - Attach screenshots, logs, videos to test results
• Combined data sources - [Values], [ValuesFromMember], [ValuesFrom<T>] with Cartesian product
• Matrix data source - [Matrix] for Cartesian product test generation
• Class data source - [ClassDataSource<T>] with shared instance support
• Typed data rows - Per-row display names, categories, tags, and skip reasons
• Explicit tests - [Explicit] to exclude from default runs
• Roslyn analyzers - Compile-time validation of test code
• Multi-scope lifecycle - Test, Class, Assembly scopes
• Parallel control - [ParallelLimit], [NotInParallel("key")], [ParallelGroup("name")]
• Execution priority - [ExecutionPriority(N)] for controlling test order
• Test dependencies - [DependsOn] with ProceedOnFailure option
• Native AOT compatible - Full trim and AOT support

Packages

Documentation

• Getting Started Guide
• Migration from xUnit
• Best Practices
• Performance methodology and results
• Full Documentation

What's Different from xUnit?

Contributing

Contributions welcome! See our Contributing Guide.

License

MIT License

Acknowledgments

Inspired by:

• TUnit - Modern architecture, source generators
• xUnit - Ergonomic assertions, proven patterns
• NUnit/MSTest - Battle-tested reliability

Built with love for .NET 10+ developers who want modern performance with familiar syntax.