It should be clear to a casual reader what code a test is testing and what results are expected. Unfortunately, that’s not usually the case with
the ExpectedException attribute since an exception could be thrown from almost any line in the method.
This rule detects MSTest and NUnit ExpectedException attribute.
Exceptions
This rule ignores:
- single-line tests, since it is obvious in such methods where the exception is expected to be thrown
- tests when it tests control flow and assertion are present in either a
catch or finally clause
[TestMethod]
[ExpectedException(typeof(InvalidOperationException))]
public void UsingTest()
{
Console.ForegroundColor = ConsoleColor.Black;
try
{
using var _ = new ConsoleAlert();
Assert.AreEqual(ConsoleColor.Red, Console.ForegroundColor);
throw new InvalidOperationException();
}
finally
{
Assert.AreEqual(ConsoleColor.Black, Console.ForegroundColor); // The exception itself is not relevant for the test.
}
}
public sealed class ConsoleAlert : IDisposable
{
private readonly ConsoleColor previous;
public ConsoleAlert()
{
previous = Console.ForegroundColor;
Console.ForegroundColor = ConsoleColor.Red;
}
public void Dispose() =>
Console.ForegroundColor = previous;
}
