Update SA1014 for function pointers

Author: sharwell

StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp9/SpacingRules/SA1014CSharp9UnitTests.cs

@@ -3,9 +3,44 @@
 
 namespace StyleCop.Analyzers.Test.CSharp9.SpacingRules
 {
+    using System.Threading;
+    using System.Threading.Tasks;
     using StyleCop.Analyzers.Test.CSharp8.SpacingRules;
+    using Xunit;
+    using static StyleCop.Analyzers.Test.Verifiers.StyleCopCodeFixVerifier<
+        StyleCop.Analyzers.SpacingRules.SA1014OpeningGenericBracketsMustBeSpacedCorrectly,
+        StyleCop.Analyzers.SpacingRules.TokenSpacingCodeFixProvider>;
 
     public partial class SA1014CSharp9UnitTests : SA1014CSharp8UnitTests
     {
+        [Fact]
+        [WorkItem(3970, "https://github.com/DotNetAnalyzers/StyleCopAnalyzers/issues/3970")]
+        public async Task TestFunctionPointerOpeningBracketSpacingAsync()
+        {
+            var testCode = @"public class TestClass
+{
+    private unsafe delegate* {|#0:<|}int, void> field1;
+    private unsafe delegate*{|#1:<|} int, void> field2;
+    private unsafe delegate* unmanaged[Cdecl] {|#2:<|}int, void> field3;
+}
+";
+
+            var fixedCode = @"public class TestClass
+{
+    private unsafe delegate*<int, void> field1;
+    private unsafe delegate*<int, void> field2;
+    private unsafe delegate* unmanaged[Cdecl]<int, void> field3;
+}
+";
+
+            var expected = new[]
+            {
+                Diagnostic().WithArguments("preceded").WithLocation(0),
+                Diagnostic().WithArguments("followed").WithLocation(1),
+                Diagnostic().WithArguments("preceded").WithLocation(2),
+            };
+
+            await VerifyCSharpFixAsync(testCode, expected, fixedCode, CancellationToken.None).ConfigureAwait(false);
+        }
     }
 }

StyleCop.Analyzers/StyleCop.Analyzers/Lightup/SyntaxKindEx.cs

@@ -70,6 +70,7 @@ internal static class SyntaxKindEx
         public const SyntaxKind NullableDirectiveTrivia = (SyntaxKind)9055;
         public const SyntaxKind FunctionPointerType = (SyntaxKind)9056;
         public const SyntaxKind FunctionPointerParameter = (SyntaxKind)9057;
+        public const SyntaxKind FunctionPointerParameterList = (SyntaxKind)9058;
         public const SyntaxKind InitAccessorDeclaration = (SyntaxKind)9060;
         public const SyntaxKind WithExpression = (SyntaxKind)9061;
         public const SyntaxKind WithInitializerExpression = (SyntaxKind)9062;

StyleCop.Analyzers/StyleCop.Analyzers/SpacingRules/SA1014OpeningGenericBracketsMustBeSpacedCorrectly.cs

@@ -11,6 +11,7 @@ namespace StyleCop.Analyzers.SpacingRules
     using Microsoft.CodeAnalysis.CSharp;
     using Microsoft.CodeAnalysis.Diagnostics;
     using StyleCop.Analyzers.Helpers;
+    using StyleCop.Analyzers.Lightup;
 
     /// <summary>
     /// An opening generic bracket within a C# element is not spaced correctly.
@@ -75,6 +76,7 @@ private static void HandleLessThanToken(SyntaxTreeAnalysisContext context, Synta
             {
             case SyntaxKind.TypeArgumentList:
             case SyntaxKind.TypeParameterList:
+            case SyntaxKindEx.FunctionPointerParameterList:
                 break;
 
             default:

documentation/SA1014.md

@@ -25,6 +25,8 @@ A violation of this rule occurs when the spacing around an opening generic brack
 
 An opening generic bracket should never be preceded or followed by whitespace, unless the bracket is the first or last character on the line.
 
+The same spacing applies to the `<` that starts a C# 9 function pointer parameter list, as in `delegate*<int, void>`.
+
 ## How to fix violations
 
 To fix a violation of this rule, ensure that there is no whitespace on either side of the opening generic bracket.