Added a new test project for c# 11

[bjornhellander]

Added test project for c# 11, to prepare for coming c# 11 tests.
(Copied c# 10 project, changed names and removed existing tests.)

[codecov]

Codecov Report

Merging #3491 (6dc6195) into master (9c5d064) will decrease coverage by 0.00%.
The diff coverage is 90.78%.

@@            Coverage Diff             @@
##           master    #3491      +/-   ##
==========================================
- Coverage   93.25%   93.24%   -0.01%     
==========================================
  Files        1066     1066              
  Lines      113311   113343      +32     
  Branches     3998     4002       +4     
==========================================
+ Hits       105664   105690      +26     
- Misses       6619     6623       +4     
- Partials     1028     1030       +2     

[sharwell]

❔ Is this different from the base class?

[sharwell]

I believe this override can be removed and the C# 11 test just use the one from C# 10

[bjornhellander]

👍

[sharwell]

Suggested change

	using System.Threading;
	using System.Threading.Tasks;
	using Microsoft.CodeAnalysis.CSharp;
	using StyleCop.Analyzers.Test.CSharp10.ReadabilityRules;
	using StyleCop.Analyzers.Test.Verifiers;
	using Xunit;
	using static StyleCop.Analyzers.Test.Verifiers.StyleCopCodeFixVerifier<
	StyleCop.Analyzers.ReadabilityRules.SA1101PrefixLocalCallsWithThis,
	StyleCop.Analyzers.ReadabilityRules.SA1101CodeFixProvider>;
	using StyleCop.Analyzers.Test.CSharp10.ReadabilityRules;

[bjornhellander]

👍

[sharwell]

Suggested change

	<PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.0.1" />
	<PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.2.0-2.final" />

[bjornhellander]

This would require an update of Microsoft.CodeAnalysis.Analyzers to version 3.3.3, which in turn would require some code fixes. Not much, but still. Ok?

[bjornhellander]

The fixes would be due to RS1034 (Prefer 'IsKind' for checking syntax kinds)

[sharwell]

That should be fine, especially if the update to 4.2.0-2.final occurs as its own commit.

[bjornhellander]

4.2.0-4.final arrived, so I used that one instead

[sharwell]

📝 This change doesn't actually allow C# 11 features. You'll need updates to the following lines to use LanguageVersion.Preview instead of the default value null:

StyleCopAnalyzers/StyleCop.Analyzers/StyleCop.Analyzers.Test/Verifiers/StyleCopCodeFixVerifier`2.cs

Line 115 in 528d635

this.LanguageVersion = languageVersion;

StyleCopAnalyzers/StyleCop.Analyzers/StyleCop.Analyzers.Test/Verifiers/StyleCopDiagnosticVerifier`1.cs

Line 67 in 528d635

this.LanguageVersion = languageVersion;

You'll want to use this default whenever LightupHelpers.SupportsCSharp11 is true, which is a new property defined right below this:

StyleCopAnalyzers/StyleCop.Analyzers/StyleCop.Analyzers/Lightup/LightupHelpers.cs

Lines 46 to 47 in 528d635

	public static bool SupportsCSharp10 { get; }
	= Enum.GetNames(typeof(LanguageVersion)).Contains(nameof(LanguageVersionEx.CSharp10));

[bjornhellander]

Using a new version of Roslyn in the c# 11 tests also fixes #3492.