Fluent Assertions compare string to Guid

Question

I am trying to find the most fluent manner to assert that a certain string is a valid Guid.

iterTags.GUID is a string.

My first attempt ended in error because stringdoes not implement Guid. Okay, I saw it coming as it was a shot in the dark

iterTags.GUID.Should().BeAssignableTo<Guid>();

So i came up with this working solution but it's not fluent

Guid parsedGuid;
if (!Guid.TryParseExact(iterTags.GUID, "D", out parsedGuid))
    Assert.Fail("iterTags.GUID: '{0}' is not a valid guid");

Reading the documentation I found no better way of doing the assertion.

My question: Is there a fluent way of asserting a string is a valid Guid

Perhaps, something like...

iterTags.GUID.Should().BeParsedAs<Guid>()

Answer 1

If you don't need to use the parsed Guid object further (requires C# 7 or above):

Guid.TryParseExact(iterTags.GUID, "D", out var _).Should().BeTrue("because {0} is a valid Guid string representation", iterTags.GUID);

or (does not require C# 7 or above)

new Action(() => new Guid(iterTags.GUID)).ShouldNotThrow("because {0} is a valid Guid string representation", iterTags.GUID);

If you need to use the parsed Guid for other things in your test, then:

Guid parsedGuid;
Guid.TryParseExact(iterTags.GUID, "D", out parsedGuid).Should().BeTrue("because {0} is a valid Guid string representation", iterTags.GUID);