Fixed issue in UsingCodeFixProvider with ValueTuple definitions under C# 7

Author: vweijsters

StyleCop.Analyzers/StyleCop.Analyzers.CodeFixes/OrderingRules/UsingCodeFixProvider.UsingsSorter.cs

@@ -13,6 +13,7 @@ namespace StyleCop.Analyzers.OrderingRules
     using Microsoft.CodeAnalysis.CSharp;
     using Microsoft.CodeAnalysis.CSharp.Syntax;
     using StyleCop.Analyzers.Helpers;
+    using StyleCop.Analyzers.Lightup;
     using StyleCop.Analyzers.Settings.ObjectModel;
 
     /// <summary>
@@ -365,15 +366,19 @@ private UsingDirectiveSyntax QualifyUsingDirective(UsingDirectiveSyntax usingDir
                             rewrittenName = replacement.WithTriviaFrom(originalName);
                             break;
                         }
-                        else if (symbol is INamedTypeSymbol)
+                        else if (symbol is INamedTypeSymbol namedTypeSymbol)
                         {
                             // TODO: Preserve inner trivia
                             // TODO: simplify after qualification
                             string fullName;
-                            if (SpecialTypeHelper.IsPredefinedType(((INamedTypeSymbol)symbol).OriginalDefinition.SpecialType))
+                            if (SpecialTypeHelper.IsPredefinedType(namedTypeSymbol.OriginalDefinition.SpecialType))
                             {
                                 fullName = "global::System." + symbol.Name;
                             }
+                            else if (namedTypeSymbol.IsTupleType())
+                            {
+                                fullName = namedTypeSymbol.TupleUnderlyingType().ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat);
+                            }
                             else
                             {
                                 fullName = symbol.ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat);

StyleCop.Analyzers/StyleCop.Analyzers.Test/OrderingRules/SA1200OutsideNamespaceUnitTests.cs

@@ -298,6 +298,56 @@ namespace TestNamespace
             await VerifyCSharpFixAsync(testCode, expectedResults, fixedTestCode, CancellationToken.None).ConfigureAwait(false);
         }
 
+        [Fact]
+        [WorkItem(2928, "https://github.com/DotNetAnalyzers/StyleCopAnalyzers/issues/2928")]
+        public async Task TestMovingValueTupleAliasOutsideAsync()
+        {
+            var testCode = @"using System;
+
+namespace MyNamespace
+{
+    using QuotesRange = ValueTuple<QuoteType, DateTime, DateTime>;
+
+    public class QuoteType
+    {
+    }
+
+    public class UseClass
+    {
+        private void Test()
+        {
+            QuotesRange t;
+        }
+    }
+}
+";
+            var fixedTestCode = @"using System;
+using QuotesRange = System.ValueTuple<MyNamespace.QuoteType, System.DateTime, System.DateTime>;
+
+namespace MyNamespace
+{
+    public class QuoteType
+    {
+    }
+
+    public class UseClass
+    {
+        private void Test()
+        {
+            QuotesRange t;
+        }
+    }
+}
+";
+
+            DiagnosticResult[] expectedResults =
+            {
+                Diagnostic(SA1200UsingDirectivesMustBePlacedCorrectly.DescriptorOutside).WithLocation(5, 5),
+            };
+
+            await VerifyCSharpFixAsync(testCode, expectedResults, fixedTestCode, CancellationToken.None).ConfigureAwait(false);
+        }
+
         private static DiagnosticResult Diagnostic(DiagnosticDescriptor descriptor)
             => StyleCopCodeFixVerifier<SA1200UsingDirectivesMustBePlacedCorrectly, UsingCodeFixProvider>.Diagnostic(descriptor);