Fix SA1015 handling of '>' followed by ']'

Fixes #3312

Author: sharwell

StyleCop.Analyzers/StyleCop.Analyzers.Test/SpacingRules/SA1015UnitTests.cs

@@ -381,5 +381,54 @@ void Method()
 
             await VerifyCSharpDiagnosticAsync(testCode, expected, CancellationToken.None).ConfigureAwait(false);
         }
+
+        [Fact]
+        [WorkItem(3312, "https://github.com/DotNetAnalyzers/StyleCopAnalyzers/issues/3312")]
+        public async Task TestSpacingInIndexAsync()
+        {
+            var testCode = @"using System;
+using System.Collections.Generic;
+
+public class TestClass
+{
+    private Dictionary<object, object> values;
+
+    public void TestMethod2(object input)
+    {
+        var x = values[input as List<int>];
+        x = values[input as List<int {|#0:>|}];
+        x = values[input as List<int{|#1:>|} ];
+        x = values[input as List<int {|#2:>|} ];
+    }
+}
+";
+
+            var fixedCode = @"using System;
+using System.Collections.Generic;
+
+public class TestClass
+{
+    private Dictionary<object, object> values;
+
+    public void TestMethod2(object input)
+    {
+        var x = values[input as List<int>];
+        x = values[input as List<int>];
+        x = values[input as List<int>];
+        x = values[input as List<int>];
+    }
+}
+";
+
+            DiagnosticResult[] expected =
+            {
+                Diagnostic(DescriptorNotPreceded).WithLocation(0),
+                Diagnostic(DescriptorNotFollowed).WithLocation(1),
+                Diagnostic(DescriptorNotPreceded).WithLocation(2),
+                Diagnostic(DescriptorNotFollowed).WithLocation(2),
+            };
+
+            await VerifyCSharpFixAsync(testCode, expected, fixedCode, CancellationToken.None).ConfigureAwait(false);
+        }
     }
 }

StyleCop.Analyzers/StyleCop.Analyzers/SpacingRules/SA1015ClosingGenericBracketsMustBeSpacedCorrectly.cs

@@ -131,6 +131,13 @@ private static void HandleGreaterThanToken(SyntaxTreeAnalysisContext context, Sy
                     allowTrailingSpace = true;
                     break;
 
+                // values[x as T<int>]
+                //                  ^^
+                case SyntaxKind.CloseBracketToken when nextToken.Parent.IsKind(SyntaxKind.BracketedArgumentList):
+                    allowTrailingNoSpace = true;
+                    allowTrailingSpace = false;
+                    break;
+
                 default:
                     allowTrailingNoSpace = false;
                     allowTrailingSpace = true;