From 33d34606a9a14362a45c008b859c124bdda5137a Mon Sep 17 00:00:00 2001 From: "Michael A. Volz" Date: Sat, 12 Jul 2025 15:15:48 +0200 Subject: [PATCH] feat: add C# TUnit testing prompt template - Added csharp-tunit.prompt.md with structured prompt template - Provides testing guidelines and best practices for C# development using TUnit framework - Includes comprehensive testing patterns for .NET projects --- csharp-tunit.prompt.md | 101 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) create mode 100644 csharp-tunit.prompt.md diff --git a/csharp-tunit.prompt.md b/csharp-tunit.prompt.md new file mode 100644 index 0000000..9d1190b --- /dev/null +++ b/csharp-tunit.prompt.md @@ -0,0 +1,101 @@ +--- +mode: 'agent' +tools: ['changes', 'codebase', 'editFiles', 'problems', 'search'] +description: 'Get best practices for TUnit unit testing, including data-driven tests' +--- + +# TUnit Best Practices + +Your goal is to help me write effective unit tests with TUnit, covering both standard and data-driven testing approaches. + +## Project Setup + +- Use a separate test project with naming convention `[ProjectName].Tests` +- Reference TUnit package and TUnit.Assertions for fluent assertions +- Create test classes that match the classes being tested (e.g., `CalculatorTests` for `Calculator`) +- Use .NET SDK test commands: `dotnet test` for running tests +- TUnit requires .NET 8.0 or higher + +## Test Structure + +- No test class attributes required (like xUnit/NUnit) +- Use `[Test]` attribute for test methods (not `[Fact]` like xUnit) +- Follow the Arrange-Act-Assert (AAA) pattern +- Name tests using the pattern `MethodName_Scenario_ExpectedBehavior` +- Use lifecycle hooks: `[Before(Test)]` for setup and `[After(Test)]` for teardown +- Use `[Before(Class)]` and `[After(Class)]` for shared context between tests in a class +- Use `[Before(Assembly)]` and `[After(Assembly)]` for shared context across test classes +- TUnit supports advanced lifecycle hooks like `[Before(TestSession)]` and `[After(TestSession)]` + +## Standard Tests + +- Keep tests focused on a single behavior +- Avoid testing multiple behaviors in one test method +- Use TUnit's fluent assertion syntax with `await Assert.That()` +- Include only the assertions needed to verify the test case +- Make tests independent and idempotent (can run in any order) +- Avoid test interdependencies (use `[DependsOn]` attribute if needed) + +## Data-Driven Tests + +- Use `[Arguments]` attribute for inline test data (equivalent to xUnit's `[InlineData]`) +- Use `[MethodData]` for method-based test data (equivalent to xUnit's `[MemberData]`) +- Use `[ClassData]` for class-based test data +- Create custom data sources by implementing `ITestDataSource` +- Use meaningful parameter names in data-driven tests +- Multiple `[Arguments]` attributes can be applied to the same test method + +## Assertions + +- Use `await Assert.That(value).IsEqualTo(expected)` for value equality +- Use `await Assert.That(value).IsSameReferenceAs(expected)` for reference equality +- Use `await Assert.That(value).IsTrue()` or `await Assert.That(value).IsFalse()` for boolean conditions +- Use `await Assert.That(collection).Contains(item)` or `await Assert.That(collection).DoesNotContain(item)` for collections +- Use `await Assert.That(value).Matches(pattern)` for regex pattern matching +- Use `await Assert.That(action).Throws()` or `await Assert.That(asyncAction).ThrowsAsync()` to test exceptions +- Chain assertions with `.And` operator: `await Assert.That(value).IsNotNull().And.IsEqualTo(expected)` +- Use `.Or` operator for alternative conditions: `await Assert.That(value).IsEqualTo(1).Or.IsEqualTo(2)` +- Use `.Within(tolerance)` for DateTime and numeric comparisons with tolerance +- All assertions are asynchronous and must be awaited + +## Advanced Features + +- Use `[Repeat(n)]` to repeat tests multiple times +- Use `[Retry(n)]` for automatic retry on failure +- Use `[ParallelLimit]` to control parallel execution limits +- Use `[Skip("reason")]` to skip tests conditionally +- Use `[DependsOn(nameof(OtherTest))]` to create test dependencies +- Use `[Timeout(milliseconds)]` to set test timeouts +- Create custom attributes by extending TUnit's base attributes + +## Test Organization + +- Group tests by feature or component +- Use `[Category("CategoryName")]` for test categorization +- Use `[DisplayName("Custom Test Name")]` for custom test names +- Consider using `TestContext` for test diagnostics and information +- Use conditional attributes like custom `[WindowsOnly]` for platform-specific tests + +## Performance and Parallel Execution + +- TUnit runs tests in parallel by default (unlike xUnit which requires explicit configuration) +- Use `[NotInParallel]` to disable parallel execution for specific tests +- Use `[ParallelLimit]` with custom limit classes to control concurrency +- Tests within the same class run sequentially by default +- Use `[Repeat(n)]` with `[ParallelLimit]` for load testing scenarios + +## Migration from xUnit + +- Replace `[Fact]` with `[Test]` +- Replace `[Theory]` with `[Test]` and use `[Arguments]` for data +- Replace `[InlineData]` with `[Arguments]` +- Replace `[MemberData]` with `[MethodData]` +- Replace `Assert.Equal` with `await Assert.That(actual).IsEqualTo(expected)` +- Replace `Assert.True` with `await Assert.That(condition).IsTrue()` +- Replace `Assert.Throws` with `await Assert.That(action).Throws()` +- Replace constructor/IDisposable with `[Before(Test)]`/`[After(Test)]` +- Replace `IClassFixture` with `[Before(Class)]`/`[After(Class)]` + +**Why TUnit over xUnit?** + +TUnit offers a modern, fast, and flexible testing experience with advanced features not present in xUnit, such as asynchronous assertions, more refined lifecycle hooks, and improved data-driven testing capabilities. TUnit's fluent assertions provide clearer and more expressive test validation, making it especially suitable for complex .NET projects. \ No newline at end of file