NUnit Best Practices

NUnit best practices for standard and data-driven unit testing in .NET projects.

- Organize tests with [TestFixture] classes matching production code, using [Test] methods named MethodName_Scenario_ExpectedBehavior and following Arrange-Act-Assert structure

- Data-driven testing via [TestCase], [TestCaseSource], [Values], [Range], and [Combinatorial] attributes for inline, programmatic, and parameterized test generation

- Use Assert.That with constraint model (Is.EqualTo, Contains.Item) and specialized assertions like CollectionAssert, StringAssert, and Assert.Throws<T> for exceptions

- Manage test lifecycle with [SetUp], [TearDown], [OneTimeSetUp], and [OneTimeTearDown] for per-test and per-class initialization

- Keep tests focused, independent, and idempotent; use [Category], [Order], and [Explicit] for organization and execution control

NUnit Best Practices

Your goal is to help me write effective unit tests with NUnit, covering both standard and data-driven testing approaches.

Project Setup

- Use a separate test project with naming convention [ProjectName].Tests

- Reference Microsoft.NET.Test.Sdk, NUnit, and NUnit3TestAdapter packages

- Create test classes that match the classes being tested (e.g., CalculatorTests for Calculator)

- Use .NET SDK test commands: dotnet test for running tests

Test Structure