What's the idiomatic way to verify collection size in xUnit?

Question

I have in my test suite a test that goes something like this:

[Fact]
public void VerifySomeStuff()
{
    var stuffCollection = GetSomeStuff();

    Assert.Equal(         


        

Answer 1

If you have more than one item, you can't use Assert.Single.

The expectation seems to be that you should use Assert.Collection:

var stuffCollection = GetSomeStuff();

Assert.Collection(stuffCollection, 
    item => true, // this lambda verifies the first item
    item => true, // second item
);

The assertion above verifies that there are exactly two items in the collection. You can provide stricter lambdas (such as item => item.property1 == 7) for each item if you want.

Personally, I'm not a fan; this seems like a very verbose way of saying how long you want the collection to be.