Comparing Resources using FluentAssertions

[LodewijkSioen]

So I'm writing integration tests. I want to compare what's returning from the server to what I'm expecting using Fluent Assertions. I want to exclude the Id and other properties that are non deterministic.

However, since Base is kind of an IDictionary, FluentAssertions keeps wanting to compare the keys and values in the dictionary.

(new Patient {Id = "123", Active = true} as object)
        .Should().BeEquivalentTo(new Patient {Active = true}, 
            o => o.Excluding(p => p.Id));

Results in:

Expected (new Patient {Id = "123", Active = true} as object) to be a collection with 1 item(s), but {[id, 123], [active, true]}"
"contains 1 item(s) more than"
"{[active, true]}.

Any known workarounds for this?

[ewoutkramer]

Yeah, it took me ages before I understood the fine details of FluentAssertions in this regard. It actually works much better if you use BeEquivalentTo() with anonymous objects, so e.g.

Patient p = new()
{
	Deceased = new FhirBoolean(true)
};

p.Should().BeEquivalentTo(new { Deceased = new FhirBoolean(true) });

Note the new {}, not new Patient {}.

[LodewijkSioen]

Yeah, it's the fact that each resource is also a Collection that confuses the equivalency algoritm. Anonymous objects bypasses that problem.
However, I've since switched to Verify to do snapshot testing, which is a much simpeler pattern.

[ewoutkramer]

We use that approach to test the intermediate steps in our new validator, though I did write something of my own. I should be using this library though.

Again, this looks like one more proof that letting the poco's implement IDictionary/IEnumerable directly was a mistake. I dont like the debug experience in vs either. Maybe we should break this in 6.0 and introduce AsIDictionary on pocos.