How to use Fluid Assertions .ShouldBeNull()

Question

I am trying to use the Fluent Assertions ShouldBeNull() extension method to assert that my instance is indeed null.

Result.ShouldBeNull();

Clearly, this throws an exception because I cannot call the extension on a null instance.

System.NullReferenceException

How do I use Fluent Assertions properly to make this assertion?

Ok, my bad. Another object was null. Still feels rather unnatural, but nothing to do with FluentAssertions I suppose. — Nick, Aug 30 '13 at 15:14

score 6 · Accepted Answer · answered Aug 30 '13 at 15:05

Extension methods can be called on objects that are null.

Think of extension methods not as instance methods, but static methods that take the object (Result in your case) as a first parameter.

score 0 · Answer 2 · answered Aug 30 '13 at 18:13

0

I wonder if you actually used FluentAssertions, because then your call should have looked like:

Result.Should().BeNull()

So with the dot .

answered Aug 30 '13 at 18:13

Dennis Doomen

score -1 · Answer 3 · answered May 02 '22 at 19:31

-1

Result needs to be nullable

result?.Should().BeNull();

Even if you're checking for null, you're still trying to do an operation on a null value.

answered May 02 '22 at 19:31

Stourme

3 Answers3