func.Should().Return(expected).After(waitTime, pollInterval);

[inikulshin]

I don't really like the code, I need to write for retrying t.GetStatus() until it returns expected value:

Action action = () => t.GetStatus().Should().Be(expected);
action.Should().NotThrowAfter(waitTime, pollInterval);

It's not "nice" and also, if action throws before the 1^st assertion (in t.GetStatus()), the 2^nd assertion won't fail immediately because NotThrowAfter catches every exception for waitTime period.

I think, a more readable and correct API should have only one Should(), e.g.

Func<int> func = () => t.GetStatus();
func.Should().Return(expected).After(waitTime, pollInterval);

or

func.After(waitTime, pollInterval).Should().Return(expected);

or even

func.After(waitTime, pollInterval).Should().ReturnValue().Which.Should().Be(expected);

I didn't get into the code, so I don't know that are limitations of every option, but the main idea is clear.