Testing Continuations?

Tests.cs

public class ClassUnderTest
{
    public static void ReturnIncrementedAfter500ms(int value, Action<int> result)
    {
        Task.Factory.StartNew(() =>
        {
            Thread.Sleep(500);
            result(value - 1);//BUG
        });
    }
}

[TestClass]
public class Tests
{
    [TestMethod]
    public void ReturnIncrementedAfter500ms_Takes1_Returns2()
    {
        var expectedOutput = 2;
        var input = 1;

        Action<int> continuation = i => Assert.AreEqual(expectedOutput, i);
        ClassUnderTest.ReturnIncrementedAfter500ms(input, continuation);
    }
}

why are expected and actually variables with different values? I do not see anything that increments a value here.

Ok, I admit, the code was a bit confusing. Take a look at the updated code. The logic in the CUT is clearly wrong (it decrements instead of increments) but the test will always be green, because the assert in the continuation is reached in a different thread, when the actual test method has been long left. The test should fail in this case.