Create analyzer/fixer for Assert.Empty

[RieBi]

A solution to issue xunit/xunit#1510, specifically the following part:

Optionally could do the same thing with Assert.Empty(...) and Assert.NotEmpty(...), mapping them to Assert.DoesNotContain(...) and Assert.Contains(...), respectively.

The analyzer and fixer apply to the following situations:
Assert.Empty(Enumerable.Where(expression))
and suggest them to change to:
Assert.DoesNotContain(Enumerable, expression)

@bradwilson hope to get feedback on it, if there's anything wrong with this

[RieBi]

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[RieBi]

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[RieBi]

This doesn't seem to work :d

[bradwilson]

This doesn't seem to work :d

I'll see if I can chase down what's going on here.

Never mind, it seems to have done it's thing:

[bradwilson]

I just wanted to stop by and let you know I'm not ignoring this PR; it's just currently prioritized behind a very large v3 rework that I'm in the middle of. I will get to this, I promise. 😄

[RieBi]

I just wanted to stop by and let you know I'm not ignoring this PR; it's just currently prioritized behind a very large v3 rework that I'm in the middle of. I will get to this, I promise. 😄

It's fine, but I want to make sure I don't do anything wrong. Can I work on making another PR now, specifically regarding the issue xunit/xunit#1511 ? Would it be fine?

[bradwilson]

Functionally everything looks great. The test coverage looks succinct and complete, and the code looks simple and easy to follow. Excellent job!

The only changes I'm going to push for you are coding style changes, all relatively minor and just me trying to keep things in the newer style that I want to push (a lot of older code is not up to date, so guessing what I'm typically looking for right now is probably impossible anyway). Mostly: I sorted namespaces, I restructured some of the tests so there was less redundant code (using more data-driven updates), and otherwise just made small stylistic changes.

I assume you intend to do the other half here as well (NotEmpty => Contains) as well before you want me to merge it?

[RieBi]

I assume you intend to do the other half here as well (NotEmpty => Contains) as well before you want me to merge it?

No, you just said before that you were working on a large rework and I started wondering if the issue is still relevant. I assume it still is. Thanks for keeping your promise of not forgetting about this PR, though :D.

I might then start working on the other half in the near future, namely on the NotEmpty => Contains, but I'll make a separate PR for that, I think it would be better that way.

[bradwilson]

Sounds good! Thanks again!