dotnet-test-frameworks

# .NET Test Framework Reference Language-specific detection patterns for .NET test frameworks (MSTest, xUnit, NUnit, TUnit). ## Test File Identification | Framework | Test class markers | Test method markers | | --------- | ------------------ | ------------------- | | MSTest | `[TestClass]` | `[TestMethod]`, `[DataTestMethod]` | | xUnit | *(none — convention-based)* | `[Fact]`, `[Theory]` | | NUnit | `[TestFixture]` | `[Test]`, `[TestCase]`, `[TestCaseSource]` | | TUnit | `[ClassDataSource]` | `[Test]` | ## Assertion APIs by Framework | Category | MSTest | xUnit | NUnit | | -------- | ------ | ----- | ----- | | Equality | `Assert.AreEqual` | `Assert.Equal` | `Assert.That(x, Is.EqualTo(y))` | | Boolean | `Assert.IsTrue` / `Assert.IsFalse` | `Assert.True` / `Assert.False` | `Assert.That(x, Is.True)` | | Null | `Assert.IsNull` / `Assert.IsNotNull` | `Assert.Null` / `Assert.NotNull` | `Assert.That(x, Is.Null)` | | Exception | `Assert.Throws<T>()` / `Assert.ThrowsExactly<T>()` | `Assert.Throws<T>()` | `Assert.That(() => ..., Throws.TypeOf<T>())` | | Collection | `CollectionAssert.Contains` | `Assert.Contains` | `Assert.That(col, Has.Member(x))` | | String | `StringAssert.Contains` | `Assert.Contains(str, sub)` | `Assert.That(str, Does.Contain(sub))` | | Type | `Assert.IsInstanceOfType` | `Assert.IsAssignableFrom` | `Assert.That(x, Is.InstanceOf<T>())` | | Inconclusive | `Assert.Inconclusive()` | *skip via `[Fact(Skip)]`* | `Assert.Inconclusive()` | | Fail | `Assert.Fail()` | `Assert.Fail()` (.NET 10+) | `Assert.Fail()` | Third-party assertion libraries: `Should*` (Shouldly), `.Should()` (FluentAssertions / AwesomeAssertions), `Verify()` (Verify). ## Sleep/Delay Patterns | Pattern | Example | | ------- | ------- | | Thread sleep | `Thread.Sleep(2000)` | | Task delay | `await Task.Delay(1000)` | | SpinWait | `SpinWait.SpinUntil(() => condition, timeout)` | ## Skip/Ignore Annotations | Framework | Annotation | With reason | | --------- | ---------- | ----------- | | MSTest | `[Ignore]` | `[Ignore("reason")]` | | xUnit | `[Fact(Skip = "reason")]` | *(reason is required)* | | NUnit | `[Ignore("reason")]` | *(reason is required)* | | TUnit | `[Skip("reason")]` | *(reason is required)* | | Conditional | `#if false` / `#if NEVER` | *(no reason possible)* | ## Exception Handling — Idiomatic Alternatives When a test uses `try`/`catch` to verify exceptions, suggest the framework-native alternative: **MSTest:** ```csharp // Instead of try/catch (matches exact type): var ex = Assert.ThrowsExactly<InvalidOperationException>( () => processor.ProcessOrder(emptyOrder)); Assert.AreEqual("Order must contain at least one item", ex.Message); // Or (also matches derived types): var ex = Assert.Throws<InvalidOperationException>( () => processor.ProcessOrder(emptyOrder)); Assert.AreEqual("Order must contain at least one item", ex.Message); ``` **xUnit:** ```csharp var ex = Assert.Throws<InvalidOperationException>( () => processor.ProcessOrder(emptyOrder)); Assert.Equal("Order must contain at least one item", ex.Message); ``` **NUnit:** ```csharp var ex = Assert.Throws<InvalidOperationException>( () => processor.ProcessOrder(emptyOrder)); Assert.That(ex.Message, Is.EqualTo("Order must contain at least one item")); ``` ## Mystery Guest — Common .NET Patterns | Smell indicator | What to look for | | --------------- | ---------------- | | File system | `File.ReadAllText`, `File.Exists`, `File.WriteAllBytes`, `Directory.GetFiles`, `Path.Combine` with hard-coded paths | | Database | `SqlConnection`, `DbContext` (without in-memory provider), `SqlCommand` | | Network | `HttpClient` without `HttpMessageHandler` override, `WebRequest`, `TcpClient` | | Environment | `Environment.GetEnvironmentVariable`, `Environment.CurrentDirectory` | | Acceptable | `MemoryStream`, `StringReader`, `InMemory` database providers, custom `DelegatingHandler` | ## Integration Test Markers Recognize these as integration tests (adjust smell severity accordingly): - Class name contains `Integration`, `E2E`, `EndToEnd`, or `Acceptance` - `[TestCategory("Integration")]` (MSTest) - `[Trait("Category", "Integration")]` (xUnit) - `[Category("Integration")]` (NUnit) - Project name ending in `.IntegrationTests` or `.E2ETests` ## Setup/Teardown Methods | Framework | Setup | Teardown | | --------- | ----- | -------- | | MSTest | `[TestInitialize]` or constructor | `[TestCleanup]` or `IDisposable.Dispose` / `IAsyncDisposable.DisposeAsync` | | xUnit | constructor | `IDisposable.Dispose` / `IAsyncDisposable.DisposeAsync` | | NUnit | `[SetUp]` | `[TearDown]` | | MSTest (class) | `[ClassInitialize]` | `[ClassCleanup]` | | NUnit (class) | `[OneTimeSetUp]` | `[OneTimeTearDown]` | | xUnit (class) | `IClassFixture<T>` | fixture's `Dispose` |