Correct code fix for SA1130 when delegate expression is part of a cast expression

[bjornhellander]

Fixes #3510

[codecov]

Codecov Report

Merging #3516 (ad03692) into master (ccaac20) will decrease coverage by 0.01%.
The diff coverage is 88.23%.

❗ Current head ad03692 differs from pull request most recent head 6a1c3ef. Consider uploading reports for the commit 6a1c3ef to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3516      +/-   ##
==========================================
- Coverage   93.26%   93.25%   -0.01%     
==========================================
  Files        1079     1079              
  Lines      113737   113782      +45     
  Branches     4027     4030       +3     
==========================================
+ Hits       106072   106111      +39     
- Misses       6630     6634       +4     
- Partials     1035     1037       +2     

[bjornhellander]

I rebased this and made some updates.

Notice the call to WithoutFormatting that I added to make the new test pass when running "fix all": https://github.com/DotNetAnalyzers/StyleCopAnalyzers/pull/3516/files#diff-b5d9ce567call to 8efc3fd5c90a2887459181165ea772d28fa805faf67a5e579e4bfccR344
Older Roslyn versions formatted the fixed code in a bad way without it. There was already a similar call in GetTransformedDocumentAsync.

[sharwell]

💡 These can use an even simpler syntax since none of the items in expected have any properties set aside from location.

Suggested change

	var z1 = (Func<int>){|#0:delegate|} { return 1; };
	var z2 = (Func<int>){|#1:delegate|}() { return 1; };
	var z3 = (Func<int, int>){|#2:delegate|} { return 1; };
	var z4 = (Func<int, int>){|#3:delegate|}(int x) { return 1; };
	var z5 = (Func<int, int, int>){|#4:delegate|} { return 1; };
	var z6 = (Func<int, int, int>){|#5:delegate|}(int x, int y) { return 1; };
	var z1 = (Func<int>)[|delegate|] { return 1; };
	var z2 = (Func<int>)[|delegate|]() { return 1; };
	var z3 = (Func<int, int>)[|delegate|] { return 1; };
	var z4 = (Func<int, int>)[|delegate|](int x) { return 1; };
	var z5 = (Func<int, int, int>)[|delegate|] { return 1; };
	var z6 = (Func<int, int, int>)[|delegate|](int x, int y) { return 1; };

[bjornhellander]

Thanks! Updated.

[sharwell]

I think DiagnosticResult.EmptyDiagnosticResult is correct here, but you should double check.

Suggested change

	var expected = new[]
	{
	Diagnostic().WithLocation(0),
	Diagnostic().WithLocation(1),
	Diagnostic().WithLocation(2),
	Diagnostic().WithLocation(3),
	Diagnostic().WithLocation(4),
	Diagnostic().WithLocation(5),
	};
	await VerifyCSharpFixAsync(testCode, expected, fixedCode, CancellationToken.None).ConfigureAwait(false);
	await VerifyCSharpFixAsync(testCode, DiagnosticResult.EmptyDiagnosticResult, fixedCode, CancellationToken.None).ConfigureAwait(false);

[bjornhellander]

Updated

[bjornhellander]

Anything else on this one, @sharwell?

[bjornhellander]

I rebased this and turned the test into a theory to make it easier to debug.

Do you have any other comments, @sharwell?