SA1137 is not raised

[Mivee]

Issue URL: #3904

Collectionexpressions are detected as variable declarations and not as InitializerExpression.

Previously they where checked based on the declaration itself (so we only have 1 Item e.g. var myVariable = [1,2,3]) . Now, for collection initializations we get the SyntaxNode from the variable and then validate each item of the collection on its own.

Since this is my first open source contribution feedback is very welcome.

I also found 2 points where I'm not sure how to proceed with:

• Microsoft.CodeAnalysis.CSharp is installed with V.1.2.1 @Stylecop.Analyzers. V.4.7.0 introduced the CollectionExpressionSyntax that would simply my IsCollectionExpression() to just a type check basiclly. Also the "workaround" with that id could be removed so imo it would be way cleaner, due to beeing 3 Major Versions behind i didnt wanted to update, since i basiclly dont know the project and also what could be affected by that upgrade.
• locally StyleCop.Analyzers.Test.CSharp8.SpacingRules.SA1009CSharp8UnitTests.TestMissingTokenAsync failed due to having a different Windows language. A possible solution could be https://stackoverflow.com/questions/5793000/is-this-a-good-approach-for-temporarily-changing-the-current-threads-culture

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.44%. Comparing base (f5843ae) to head (d22f8a0).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #3910   +/-   ##
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  Coverage   97.44%   97.44%           
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  Files         926      932    +6     
  Lines      110283   110380   +97     
  Branches     3319     3320    +1     
=======================================
+ Hits       107467   107564   +97     
  Misses       1847     1847           
  Partials      969      969           

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[bjornhellander]

I don't think this is the correct way of handling this, since collection expressions can be used in other places besides declarations.
Try adding another test with e.g. an assignment statement using a collection expression, to verify that.

This triggers the corresponding handling of initializer expressions:
https://github.com/DotNetAnalyzers/StyleCopAnalyzers/blob/master/StyleCop.Analyzers/StyleCop.Analyzers/ReadabilityRules/SA1137ElementsShouldHaveTheSameIndentation.cs#L79
Unless I am missing something, collection expressions should be handled in a similar way.

SyntaxKindEx contains CollectionExpression, but the Lightup folder in the analyzer project should also be updated to include support for collection expressions. This has not yet been added to the repo as far as I can see. @sharwell would need to do this, or at least describe what to do. This is to avoid the call to ChildNodes(), which seems to work fine, but is not the normal way of accessing syntax nodes in this repository.