Fixed SA1135 bug

Author: vweijsters

StyleCop.Analyzers/StyleCop.Analyzers.Test/Verifiers/GenericAnalyzerTest.cs

@@ -25,7 +25,7 @@ static GenericAnalyzerTest()
                 {
                     1 => "1.2.1",
                     2 => "2.8.2",
-                    3 => "3.3.1",
+                    3 => "3.6.0",
                     _ => throw new InvalidOperationException("Unknown version."),
                 };
 

StyleCop.Analyzers/StyleCop.Analyzers/Helpers/SymbolNameHelpers.cs

@@ -3,6 +3,7 @@
 
 namespace StyleCop.Analyzers.Helpers
 {
+    using System.Reflection;
     using System.Text;
     using Microsoft.CodeAnalysis;
     using Microsoft.CodeAnalysis.CSharp;
@@ -46,10 +47,12 @@ public static string ToFullyQualifiedValueTupleDisplayString(this INamedTypeSymb
             var tupleElements = tupleSymbol.TupleElements();
             if (tupleElements.IsDefault)
             {
+                // If the tuple elements API is not available, the default formatting will produce System.ValueTuple and not the C# tuple format.
                 return tupleSymbol.ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat);
             }
             else
             {
+                // workaround for SymbolDisplayCompilerInternalOptions.UseValueTuple not being available to us.
                 var builder = ObjectPools.StringBuilderPool.Allocate();
 
                 builder.Append("global::System.ValueTuple<");
@@ -206,7 +209,7 @@ private static bool AppendTupleType(StringBuilder builder, INamedTypeSymbol name
             }
             else
             {
-                return AppendQualifiedSymbolName(builder, namedTypeSymbol.TupleUnderlyingType(), type);
+				return AppendNamedType(builder, namedTypeSymbol.TupleUnderlyingTypeOrSelf(), type);
             }
         }
 

StyleCop.Analyzers/StyleCop.Analyzers/ReadabilityRules/SA1135UsingDirectivesMustBeQualified.cs

@@ -95,7 +95,7 @@ private static void CheckUsingDeclaration(SyntaxNodeAnalysisContext context, Usi
             if (symbol is INamedTypeSymbol typeSymbol
                 && typeSymbol.IsTupleType())
             {
-                symbol = typeSymbol.TupleUnderlyingType();
+                symbol = typeSymbol.TupleUnderlyingTypeOrSelf();
             }
 
             string symbolString = symbol.ToQualifiedString(usingDirective.Name);