NUnit

Ported from JUnit, NUnit is one of the oldest and most feature-rich frameworks for .NET. Ideally suited for complex test setups and legacy migrations.

When to Use

• Legacy/Enterprise: Large existing codebases often use NUnit.
• Complex Lifecycle: If you really need [OneTimeSetUp], [SetUp], [TearDown] hooks which xUnit discourages.
• Parallelism: Strong parallel execution support ([Parallelizable]).

Quick Start

using NUnit.Framework;