[Test]
public async Task User_Creation_Should_Set_Timestamp()
{
    // Arrange
    var userService = new UserService();
    // Act
    var user = await userService.CreateUserAsync("john.doe@example.com");
    // Assert - TUnit's fluent assertions
    await Assert.That(user.CreatedAt)
        .IsEqualTo(DateTime.Now)
        .Within(TimeSpan.FromMinutes(1));
    await Assert.That(user.Email)
        .IsEqualTo("john.doe@example.com");
}

[Test]
[Arguments("user1@test.com", "ValidPassword123")]
[Arguments("user2@test.com", "AnotherPassword456")]
[Arguments("admin@test.com", "AdminPass789")]
public async Task User_Login_Should_Succeed(string email, string password)
{
    var result = await authService.LoginAsync(email, password);
    await Assert.That(result.IsSuccess).IsTrue();
}
// Matrix testing - tests all combinations
[Test]
[MatrixDataSource]
public async Task Database_Operations_Work(
    [Matrix("Create", "Update", "Delete")] string operation,
    [Matrix("User", "Product", "Order")] string entity)
{
    await Assert.That(await ExecuteOperation(operation, entity))
        .IsTrue();
}

[Before(Class)]
public static async Task SetupDatabase(ClassHookContext context)
{
    await DatabaseHelper.InitializeAsync();
}
[Test, DisplayName("Register a new account")]
[MethodDataSource(nameof(GetTestUsers))]
public async Task Register_User(string username, string password)
{
    // Test implementation
}
[Test, DependsOn(nameof(Register_User))]
[Retry(3)] // Retry on failure
public async Task Login_With_Registered_User(string username, string password)
{
    // This test runs after Register_User completes
}
[Test]
[ParallelLimit<LoadTestParallelLimit>] // Custom parallel control
[Repeat(100)] // Run 100 times
public async Task Load_Test_Homepage()
{
    // Performance testing
}
// Custom attributes
[Test, WindowsOnly, RetryOnHttpError(5)]
public async Task Windows_Specific_Feature()
{
    // Platform-specific test with custom retry logic
}
public class LoadTestParallelLimit : IParallelLimit
{
    public int Limit => 10; // Limit to 10 concurrent executions
}

// Custom conditional execution
public class WindowsOnlyAttribute : SkipAttribute
{
    public WindowsOnlyAttribute() : base("Windows only test") { }
    public override Task<bool> ShouldSkip(TestContext testContext)
        => Task.FromResult(!OperatingSystem.IsWindows());
}
// Custom retry logic
public class RetryOnHttpErrorAttribute : RetryAttribute
{
    public RetryOnHttpErrorAttribute(int times) : base(times) { }
    public override Task<bool> ShouldRetry(TestInformation testInformation,
        Exception exception, int currentRetryCount)
        => Task.FromResult(exception is HttpRequestException { StatusCode: HttpStatusCode.ServiceUnavailable });
}

// Enhanced with TUnit's advanced features
[Test]
[Arguments("value1")]
[Arguments("value2")]
[Retry(3)]
[ParallelLimit<CustomLimit>]
public async Task Modern_TUnit_Test(string value) { }