Address bugs in impl

src/Features/CSharp/Portable/UseSimpleUsingStatement/UseSimpleUsingStatementCodeFixProvider.cs

@@ -17,7 +17,7 @@
 using Microsoft.CodeAnalysis.Shared.Extensions;
 using Roslyn.Utilities;
 
-namespace Microsoft.CodeAnalysis.CSharp.UseSimpleUsingDeclaration
+namespace Microsoft.CodeAnalysis.CSharp.UseSimpleUsingStatement
 {
     [ExportCodeFixProvider(LanguageNames.CSharp, Name = nameof(UseSimpleUsingStatementCodeFixProvider)), Shared]
     internal class UseSimpleUsingStatementCodeFixProvider : SyntaxEditorBasedCodeFixProvider
@@ -38,9 +38,23 @@ public override Task RegisterCodeFixesAsync(CodeFixContext context)
             Document document, ImmutableArray<Diagnostic> diagnostics,
             SyntaxEditor editor, CancellationToken cancellationToken)
         {
-            var usingStatements = diagnostics.Select(d => (UsingStatementSyntax)d.AdditionalLocations[0].FindNode(cancellationToken)).ToSet();
-
-            var rewriter = new Rewriter(usingStatements);
+            var directUsingStatements = diagnostics.SelectAsArray(d => (UsingStatementSyntax)d.AdditionalLocations[0].FindNode(cancellationToken));
+
+            // Grab all the convertible usings in a block of nested usings.  i.e.
+            // 
+            //      using (...)
+            //      using (...)
+            //      using (...)
+            //      {
+            //      }
+            //
+            // If invoked on any of these , we'll convert in all in teh group that we can.
+
+            // Importantly, this is a set, so if we're doing a fix-all, we may add the items
+            // multiple times, but that's ok as it will still only be in the set once.
+            var allUsingStatements = GetUsingStatementsToUpdate(directUsingStatements);
+
+            var rewriter = new Rewriter(allUsingStatements);
             var root = editor.OriginalRoot;
             var updatedRoot = rewriter.Visit(root);
 
@@ -49,6 +63,29 @@ public override Task RegisterCodeFixesAsync(CodeFixContext context)
             return Task.CompletedTask;
         }
 
+        private static HashSet<UsingStatementSyntax> GetUsingStatementsToUpdate(ImmutableArray<UsingStatementSyntax> directUsingStatements)
+        {
+            var allUsingStatements = new HashSet<UsingStatementSyntax>();
+
+            foreach (var usingStatement in directUsingStatements)
+            {
+                // First, walk up to the topmost using statement in this chain that is convertible
+                var topmostUsingStatement = (UsingStatementSyntax)usingStatement.AncestorsAndSelf().TakeWhile(
+                    n => n is UsingStatementSyntax ancestor &&
+                         UseSimpleUsingStatementDiagnosticAnalyzer.CanConvertUsingStatement(ancestor)).Last();
+
+                // Then walk inwards adding all using statements that are convertible.
+                for (var current = topmostUsingStatement;
+                     current != null && UseSimpleUsingStatementDiagnosticAnalyzer.CanConvertUsingStatement(current);
+                     current = current.Statement as UsingStatementSyntax)
+                {
+                    allUsingStatements.Add(current);
+                }
+            }
+
+            return allUsingStatements;
+        }
+
         private class Rewriter : CSharpSyntaxRewriter
         {
             private readonly ISet<UsingStatementSyntax> _usingStatements;
@@ -91,29 +128,6 @@ private static LocalDeclarationStatementSyntax Convert(UsingStatementSyntax usin
                     SyntaxFactory.Token(SyntaxKind.SemicolonToken));
             }
 
-            public override SyntaxNode VisitElseClause(ElseClauseSyntax node)
-            {
-                // First, descend into the else-clause so we fixup any using statements contained
-                // inside of it.
-                var rewrittenElse = (ElseClauseSyntax)base.VisitElseClause(node);
-
-                // Now, if the else-clause previous pointed at a using statement we wanted to
-                // rewrite, and it still points at a using statement, then expand that using
-                // statemnet into the else-clause.
-                var rewrittenStatement = rewrittenElse.Statement;
-                if (ShouldExpand(node.Statement, rewrittenStatement))
-                {
-                    // Can't expand a using-statement directly inside an else-clause.
-                    // have to add a block around it to make sure scoping is preserved
-                    // properly.
-                    var expanded = Expand((UsingStatementSyntax)rewrittenStatement);
-                    return rewrittenElse.WithStatement(SyntaxFactory.Block(expanded))
-                                        .WithAdditionalAnnotations(Formatter.Annotation);
-                }
-
-                return rewrittenElse;
-            }
-
             private bool ExpandAppropriateStatements(
                 SyntaxList<StatementSyntax> originalStatements,
                 SyntaxList<StatementSyntax> rewrittenStatements,
@@ -166,29 +180,27 @@ private SyntaxNode VisitBlockWorker(BlockSyntax node, ArrayBuilder<StatementSynt
                                      .WithAdditionalAnnotations(Formatter.Annotation);
             }
 
-            public override SyntaxNode VisitSwitchSection(SwitchSectionSyntax node)
+            public override SyntaxNode VisitUsingStatement(UsingStatementSyntax node)
             {
-                var finalStatements = ArrayBuilder<StatementSyntax>.GetInstance();
-                var result = VisitSwitchSectionWorker(node, finalStatements);
-                finalStatements.Free();
-
-                return result;
-            }
-
-            private SyntaxNode VisitSwitchSectionWorker(SwitchSectionSyntax node, ArrayBuilder<StatementSyntax> finalStatements)
-            {
-                var rewrittenSwitchSection = (SwitchSectionSyntax)base.VisitSwitchSection(node);
-
-                var changed = ExpandAppropriateStatements(node.Statements, rewrittenSwitchSection.Statements, finalStatements);
+                // First, descend into the using-statement so we fixup any using statements contained
+                // inside of it.
+                var rewrittenUsingStatement = (UsingStatementSyntax)base.VisitUsingStatement(node);
 
-                if (!changed)
+                // Now, if the else-clause previous pointed at a using statement we wanted to
+                // rewrite, and it still points at a using statement, then expand that using
+                // statemnet into the else-clause.
+                var rewrittenStatement = rewrittenUsingStatement.Statement;
+                if (ShouldExpand(node.Statement, rewrittenStatement))
                 {
-                    // Didn't update any children.  Just return as is.
-                    return rewrittenSwitchSection;
+                    // Can't expand a using-statement directly inside an else-clause.
+                    // have to add a block around it to make sure scoping is preserved
+                    // properly.
+                    var expanded = Expand((UsingStatementSyntax)rewrittenStatement);
+                    return rewrittenUsingStatement.WithStatement(SyntaxFactory.Block(expanded))
+                                                  .WithAdditionalAnnotations(Formatter.Annotation);
                 }
 
-                return rewrittenSwitchSection.WithStatements(new SyntaxList<StatementSyntax>(finalStatements))
-                                             .WithAdditionalAnnotations(Formatter.Annotation);
+                return rewrittenUsingStatement;
             }
         }
 

src/Features/CSharp/Portable/UseSimpleUsingStatement/UseSimpleUsingStatementDiagnosticAnalyzer.cs

@@ -30,10 +30,6 @@ protected override void InitializeWorker(AnalysisContext context)
         private void AnalyzeSyntax(SyntaxNodeAnalysisContext context)
         {
             var usingStatement = (UsingStatementSyntax)context.Node;
-            if (usingStatement.Declaration == null)
-            {
-                return;
-            }
 
             var syntaxTree = context.Node.SyntaxTree;
             //var options = (CSharpParseOptions)syntaxTree.Options;
@@ -55,12 +51,28 @@ private void AnalyzeSyntax(SyntaxNodeAnalysisContext context)
                 return;
             }
 
+            if (CanConvertUsingStatement(usingStatement))
+            {
+                context.ReportDiagnostic(DiagnosticHelper.Create(
+                    Descriptor,
+                    usingStatement.UsingKeyword.GetLocation(),
+                    option.Notification.Severity,
+                    additionalLocations: ImmutableArray.Create(usingStatement.GetLocation()),
+                    properties: null));
+            }
+        }
+
+        public static bool CanConvertUsingStatement(UsingStatementSyntax usingStatement)
+        {
+            if (usingStatement.Declaration == null)
+            {
+                return false;
+            }
+
             var parent = usingStatement.Parent;
-            var okParent = parent is BlockSyntax ||
-                           parent is SwitchSectionSyntax;
-            if (!okParent)
+            if (!(parent is BlockSyntax || parent is UsingStatementSyntax))
             {
-                return;
+                return false;
             }
 
             // Has to be one of the following forms:
@@ -72,22 +84,8 @@ private void AnalyzeSyntax(SyntaxNodeAnalysisContext context)
             //    the resource, instead of afterwards.  Effectly, the statement following
             //    cannot actually execute any code that might depend on the .Dispose method
             //    being called or not.
-            var statements = GetStatements(parent, usingStatement);
-            if (CanConvertUsingStatement(statements, usingStatement))
-            {
-                context.ReportDiagnostic(DiagnosticHelper.Create(
-                    Descriptor,
-                    usingStatement.UsingKeyword.GetLocation(),
-                    option.Notification.Severity,
-                    additionalLocations: ImmutableArray.Create(usingStatement.GetLocation()),
-                    properties: null));
-            }
-        }
+            var statements = GetStatements(parent);
 
-        private bool CanConvertUsingStatement(
-            SyntaxList<StatementSyntax> statements,
-            UsingStatementSyntax usingStatement)
-        {
             var index = statements.IndexOf(usingStatement);
             if (index == statements.Count - 1)
             {
@@ -123,12 +121,12 @@ private void AnalyzeSyntax(SyntaxNodeAnalysisContext context)
             return false;
         }
 
-        private SyntaxList<StatementSyntax> GetStatements(SyntaxNode parent, UsingStatementSyntax usingStatement)
+        private static SyntaxList<StatementSyntax> GetStatements(SyntaxNode parent)
         {
             switch (parent)
             {
                 case BlockSyntax block: return block.Statements;
-                case SwitchSectionSyntax switchSection: return switchSection.Statements;
+                case UsingStatementSyntax usingStatement: return new SyntaxList<StatementSyntax>(usingStatement.Statement);
                 default: throw ExceptionUtilities.UnexpectedValue(parent);
             }
         }

src/Features/Core/Portable/xlf/FeaturesResources.cs.xlf

@@ -2475,7 +2475,7 @@ Tato verze se používá zde: {2}.</target>
         <target state="new">updating usages in dependent projects</target>
         <note />
       </trans-unit>
-      <trans-unit id="using_statment_can_be_simplified">
+      <trans-unit id="using_statement_can_be_simplified">
         <source>'using' statement can be simplified</source>
         <target state="new">'using' statement can be simplified</target>
         <note />

src/Features/Core/Portable/xlf/FeaturesResources.de.xlf

@@ -2475,7 +2475,7 @@ Diese Version wird verwendet in: {2}</target>
         <target state="new">updating usages in dependent projects</target>
         <note />
       </trans-unit>
-      <trans-unit id="using_statment_can_be_simplified">
+      <trans-unit id="using_statement_can_be_simplified">
         <source>'using' statement can be simplified</source>
         <target state="new">'using' statement can be simplified</target>
         <note />

src/Features/Core/Portable/xlf/FeaturesResources.es.xlf

@@ -2475,7 +2475,7 @@ Esta versión se utiliza en: {2}</target>
         <target state="new">updating usages in dependent projects</target>
         <note />
       </trans-unit>
-      <trans-unit id="using_statment_can_be_simplified">
+      <trans-unit id="using_statement_can_be_simplified">
         <source>'using' statement can be simplified</source>
         <target state="new">'using' statement can be simplified</target>
         <note />

src/Features/Core/Portable/xlf/FeaturesResources.fr.xlf

@@ -2475,7 +2475,7 @@ Version utilisée dans : {2}</target>
         <target state="new">updating usages in dependent projects</target>
         <note />
       </trans-unit>
-      <trans-unit id="using_statment_can_be_simplified">
+      <trans-unit id="using_statement_can_be_simplified">
         <source>'using' statement can be simplified</source>
         <target state="new">'using' statement can be simplified</target>
         <note />

src/Features/Core/Portable/xlf/FeaturesResources.it.xlf

@@ -2475,7 +2475,7 @@ Questa versione è usata {2}</target>
         <target state="new">updating usages in dependent projects</target>
         <note />
       </trans-unit>
-      <trans-unit id="using_statment_can_be_simplified">
+      <trans-unit id="using_statement_can_be_simplified">
         <source>'using' statement can be simplified</source>
         <target state="new">'using' statement can be simplified</target>
         <note />

src/Features/Core/Portable/xlf/FeaturesResources.ja.xlf

@@ -2475,7 +2475,7 @@ This version used in: {2}</source>
         <target state="new">updating usages in dependent projects</target>
         <note />
       </trans-unit>
-      <trans-unit id="using_statment_can_be_simplified">
+      <trans-unit id="using_statement_can_be_simplified">
         <source>'using' statement can be simplified</source>
         <target state="new">'using' statement can be simplified</target>
         <note />

src/Features/Core/Portable/xlf/FeaturesResources.ko.xlf

@@ -2475,7 +2475,7 @@ This version used in: {2}</source>
         <target state="new">updating usages in dependent projects</target>
         <note />
       </trans-unit>
-      <trans-unit id="using_statment_can_be_simplified">
+      <trans-unit id="using_statement_can_be_simplified">
         <source>'using' statement can be simplified</source>
         <target state="new">'using' statement can be simplified</target>
         <note />

src/Features/Core/Portable/xlf/FeaturesResources.pl.xlf

@@ -2475,7 +2475,7 @@ Ta wersja jest używana wersja: {2}</target>
         <target state="new">updating usages in dependent projects</target>
         <note />
       </trans-unit>
-      <trans-unit id="using_statment_can_be_simplified">
+      <trans-unit id="using_statement_can_be_simplified">
         <source>'using' statement can be simplified</source>
         <target state="new">'using' statement can be simplified</target>
         <note />

src/Features/Core/Portable/xlf/FeaturesResources.pt-BR.xlf

@@ -2475,7 +2475,7 @@ Essa versão é usada no: {2}</target>
         <target state="new">updating usages in dependent projects</target>
         <note />
       </trans-unit>
-      <trans-unit id="using_statment_can_be_simplified">
+      <trans-unit id="using_statement_can_be_simplified">
         <source>'using' statement can be simplified</source>
         <target state="new">'using' statement can be simplified</target>
         <note />

src/Features/Core/Portable/xlf/FeaturesResources.ru.xlf

@@ -2475,7 +2475,7 @@ This version used in: {2}</source>
         <target state="new">updating usages in dependent projects</target>
         <note />
       </trans-unit>
-      <trans-unit id="using_statment_can_be_simplified">
+      <trans-unit id="using_statement_can_be_simplified">
         <source>'using' statement can be simplified</source>
         <target state="new">'using' statement can be simplified</target>
         <note />

src/Features/Core/Portable/xlf/FeaturesResources.tr.xlf

@@ -2475,7 +2475,7 @@ Bu sürüm şurada kullanılır: {2}</target>
         <target state="new">updating usages in dependent projects</target>
         <note />
       </trans-unit>
-      <trans-unit id="using_statment_can_be_simplified">
+      <trans-unit id="using_statement_can_be_simplified">
         <source>'using' statement can be simplified</source>
         <target state="new">'using' statement can be simplified</target>
         <note />

src/Features/Core/Portable/xlf/FeaturesResources.zh-Hans.xlf

@@ -2475,7 +2475,7 @@ This version used in: {2}</source>
         <target state="new">updating usages in dependent projects</target>
         <note />
       </trans-unit>
-      <trans-unit id="using_statment_can_be_simplified">
+      <trans-unit id="using_statement_can_be_simplified">
         <source>'using' statement can be simplified</source>
         <target state="new">'using' statement can be simplified</target>
         <note />

src/Features/Core/Portable/xlf/FeaturesResources.zh-Hant.xlf

@@ -2475,7 +2475,7 @@ This version used in: {2}</source>
         <target state="new">updating usages in dependent projects</target>
         <note />
       </trans-unit>
-      <trans-unit id="using_statment_can_be_simplified">
+      <trans-unit id="using_statement_can_be_simplified">
         <source>'using' statement can be simplified</source>
         <target state="new">'using' statement can be simplified</target>
         <note />