Agent skill · software engineering · github
csharp-xunit
Get best practices for XUnit unit testing, including data-driven tests
Why this skill is useful
Codifies best practices for XUnit unit testing, which the AI could infer but now doesn't have to guess.
What it needs
About 2k tokens when loaded. Last updated 2026-08-07. 37,534 stars on the source repository.
What this skill does
XUnit Best Practices Your goal is to help me write effective unit tests with XUnit, 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, xunit, and xunit.runner.visualstudio 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 No test class attributes required (unlike MSTest/NUnit) Use fact-based tests with [Fact] attribute for simple tests Follow the Arrange-Act-Assert (AAA) pattern Name tests using the pattern MethodNameScenarioExpectedBehavior Use constructor for setup and IDisposable.Dispose() for teardown Use IClassFixture<T> for shared context between tests in a class Use ICollectionFixture<T> for shared context between multiple test classes Standard Tests Keep tests focused on a single behavior Avoid testing multiple behaviors in one test method Use clear assertions that express intent Include only the assertions needed to verify the test case Make tests independent and idempotent (can run in any order) Avoid test interdependencies Data-Driven Tests Use [Theory] combined with data source attributes Use [InlineData] for inline test data Use [MemberData] for method-based test data Use [ClassData] for class-based test data Create custom data attributes by implementing DataAttribute Use meaningful parameter names in data-driven tests Assertions Use Assert.Equal for value equality Use Assert.Same for reference equality Use Assert.True/Assert.False for boolean conditions Use Assert.Contains/Assert.DoesNotContain for collections Use Assert.Matches/Assert.DoesNotMatch for regex pattern matching Use Assert.Throws<T> or await Assert.ThrowsAsync<T> to test exceptions Use fluent assertions library for more readable assertions Mocking and Isolation Consider using Moq or NSubstitute alongside XUnit Mock dependencies to isolate u …
How to use it
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@skills github/csharp-xunit