Can the use of IsNotNull affect nullability checks?

[runenur]

After I have used IsNotNull to assert that a variable is not null, I still have to treat it as if it could be null later on in the test:

await Assert.That(result).IsNotNull();
await Assert.That(result?.Status).IsEqualTo("Completed");

The use of ?. here feels unnecessary. Could it be annotated somehow? Or is it possible to use Roslyn analyzers to affect nullability checks?

[viceroypenguin]

@thomhurst if [NotNull] is added to the value parameter, then that will address this. NRT flow analysis expects that anything that is passed to a [NotNull] parameter is no longer null after that method returns.

[vbreuss]

But that would be incorrect, e.g.

object? sut = null;
await Assert.That(sut).IsNull();

Would tell the compiler that sut is not null

[viceroypenguin]

Ah, right.

[vbreuss]

The "Problem" is, that the actual check is in an extension method, without the subject as direct parameter.