Requires.NotEmpty(Guid)

[scottdorman]

The Requires.NotEmpty(Guid) method here was replaced with Requires.NotDefault, which creates an inconsistency with Microsoft.VisualStudio.Validation. Should we update that repo to match? This is tangentially related to #38.

[AArnott]

The Requires.NotEmpty(Guid) method here was replaced

I can't find any evidence that that API used to be in this library. At least as of 2.4.22, it seems the Requires class didn't have that method. The vs-validation library does define that method.
Of the two, I prefer NotDefault<T> because it works for more parameter types. Are you proposing that we add NotDefault<T> to vs-validation or that we add NotEmpty(Guid) to this repo?

[scottdorman]

Correct, NotEmpty(Guid) never existed here. I also prefer NotDefault<T>. I was thinking that NotDefault<T> should probably be added to vs-validation and have NotEmpty(Guid) be removed. I put the issue here as I wasn't sure which direction you might want it to go (vs-validation => here or here => vs-validation).

[AArnott]

and have NotEmpty(Guid) be removed

That's never going to happen. vs-validation is used in many Microsoft components and thus has a high backward compat obligation.
I don't mind copying NotDefault<T> from here to vs-validation, but that's probably all I'd want to do.

[scottdorman]

As I was looking at vs-validation for the other PR, I noticed that it's not just NotDefault<T> which is missing. It's also missing That, ValidState, and the new ValidElements<T> methods. Should those get pulled in as well (along with their associated tests)?

[AArnott]

I'm in favor of copying the following to vs-validation: ValidElements<T>, NotDefault<T>.

Let us not copy over ValidState (which is redundant with Verify.Operation which is the better API for it). We should [Obsolete] the ValidState API with a message telling folks to use Verify.Operation instead.

That is similarly redundant with Requires.Argument and should be deprecated. Having redundant methods for the sake of sounding "fluent" makes an API more confusing, IMO.

[scottdorman]

That all makes sense. I'll have a PR shortly for that. Should we also add [Obsolete] to NotEmtpy(Guid) or should it simply be a call to NotDefault?

[AArnott]

Let's leave NotEmpty(Guid) alone. It's in vs-validation and we won't be obsoleting it there.