Ignore virtual files

[ryanbrandenburg]

Fixes dotnet/aspnetcore#18927.

This seemed to require editing a lot of test files to exclude the Blazor project from running other tests, if anyone on the O# side has a better way to handle that I'm open.

CC @NTaylorMullen, @ajaybhargavb

[ryanbrandenburg]

@JoeRobich / @filipw I'm not 100% sure this is the correct fix, maybe you could correct my thinking (or convince me I'm already right).

Repro steps:

1. dotnet new blazorserver
2. In Index.razor add the line @DoesNotExist.
3. Watch the Problems pane, you should see an entry for Index.razor_virtual.cs flash briefly (occasionally it stays permanently). If you didn't see it try again, it should repro each time.

When I track this down I can find requests to _validateDocument for the Index.cshtml_virtual.cs file, which has returned a result for Index.cshtml, even though the request was for _virtual.cs.

Hopefully that all makes sense, I can go into more detail offline if you need more context or a demo.

[JoeRobich]

@ryanbrandenburg I tried the step you listed and this is what I see in the latest release 1.21.12. I do see a reported problem, but it is for Index.razor.

[JoeRobich]

@ryanbrandenburg I spoke too soon. I see what you are talking about.

[codecov]

Codecov Report

Merging #3592 into master will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff           @@
##           master   #3592   +/-   ##
======================================
  Coverage    89.8%   89.8%           
======================================
  Files          59      59           
  Lines        1589    1589           
  Branches       89      89           
======================================
  Hits         1427    1427           
  Misses        151     151           
  Partials       11      11

Flag	Coverage Δ
#integration	?
#unit	89.8% <ø> (ø)	⬆️

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[ryanbrandenburg]

@JoeRobich, I've updated it with your feedback but it seems I don't have permissions to merge.

[JoeRobich]

Thanks @ryanbrandenburg !