Merge pull request #18740 from sys27/fix/17177

Unresolvable conflict not indicated when renaming identifier.

src/EditorFeatures/Test2/Rename/CSharp/LocalConflictTests.vb

@@ -466,5 +466,140 @@ namespace ConsoleApplication1
                 result.AssertLabeledSpansAre("stmt2", "this.list = list.ToList();", RelatedLocationType.ResolvedReferenceConflict)
             End Using
         End Sub
+
+        <Fact>
+        <Trait(Traits.Feature, Traits.Features.Rename)>
+        <WorkItem(17177, "https://github.com/dotnet/roslyn/issues/17177")>
+        Public Sub ConflictsBetweenSwitchCaseStatementsWithoutBlocks()
+            Using result = RenameEngineResult.Create(_outputHelper,
+                <Workspace>
+                    <Project Language="C#" CommonReferences="true">
+                        <Document>
+class Test
+{
+    static void Main()
+    {
+        switch (true)
+        {
+            case true:
+                object {|stmt1:$$i|} = null;
+                break;
+            case false:
+                object {|stmt2:j|} = null;
+                break;
+        }
+    }
+}
+                            </Document>
+                    </Project>
+                </Workspace>, renameTo:="j")
+
+                result.AssertLabeledSpansAre("stmt1", "j", RelatedLocationType.NoConflict)
+                result.AssertLabeledSpansAre("stmt2", "j", RelatedLocationType.UnresolvableConflict)
+            End Using
+        End Sub
+
+        <Fact>
+        <Trait(Traits.Feature, Traits.Features.Rename)>
+        <WorkItem(17177, "https://github.com/dotnet/roslyn/issues/17177")>
+        Public Sub NoConflictsBetweenSwitchCaseStatementsWithBlocks()
+            Using result = RenameEngineResult.Create(_outputHelper,
+                <Workspace>
+                    <Project Language="C#" CommonReferences="true">
+                        <Document>
+class Test
+{
+    static void Main()
+    {
+        switch (true)
+        {
+            case true:
+                {
+                    object {|stmt1:$$i|} = null;
+                    break;
+                }
+            case false:
+                {
+                    object j = null;
+                    break;
+                }
+        }
+    }
+}
+                        </Document>
+                    </Project>
+                </Workspace>, renameTo:="j")
+
+                result.AssertLabeledSpansAre("stmt1", "j", RelatedLocationType.NoConflict)
+            End Using
+        End Sub
+
+        <Fact>
+        <Trait(Traits.Feature, Traits.Features.Rename)>
+        <WorkItem(17177, "https://github.com/dotnet/roslyn/issues/17177")>
+        Public Sub NoConflictsBetweenSwitchCaseStatementFirstStatementWithBlock()
+            Using result = RenameEngineResult.Create(_outputHelper,
+                <Workspace>
+                    <Project Language="C#" CommonReferences="true">
+                        <Document>
+class Test
+{
+    static void Main()
+    {
+        switch (true)
+        {
+            case true:
+                {
+                    object {|stmt1:$$i|} = null;
+                    break;
+                }
+            case false:
+                object {|stmt2:j|} = null;
+                break;
+        }
+    }
+}
+                        </Document>
+                    </Project>
+                </Workspace>, renameTo:="j")
+
+                result.AssertLabeledSpansAre("stmt1", "j", RelatedLocationType.NoConflict)
+                result.AssertLabeledSpansAre("stmt2", "j", RelatedLocationType.UnresolvableConflict)
+            End Using
+        End Sub
+
+        <Fact>
+        <Trait(Traits.Feature, Traits.Features.Rename)>
+        <WorkItem(17177, "https://github.com/dotnet/roslyn/issues/17177")>
+        Public Sub NoConflictsBetweenSwitchCaseStatementSecondStatementWithBlock()
+            Using result = RenameEngineResult.Create(_outputHelper,
+                <Workspace>
+                    <Project Language="C#" CommonReferences="true">
+                        <Document>
+class Test
+{
+    static void Main()
+    {
+        switch (true)
+        {
+            case true:
+                object {|stmt1:$$i|} = null;
+                break;
+            case false:
+                {
+                    object {|stmt2:j|} = null;
+                    break;
+                }
+        }
+    }
+}
+                        </Document>
+                    </Project>
+                </Workspace>, renameTo:="j")
+
+                result.AssertLabeledSpansAre("stmt1", "j", RelatedLocationType.NoConflict)
+                result.AssertLabeledSpansAre("stmt2", "j", RelatedLocationType.UnresolvableConflict)
+            End Using
+        End Sub
     End Class
 End Namespace

src/Workspaces/CSharp/Portable/Rename/LocalConflictVisitor.cs

@@ -37,12 +37,17 @@ public override void VisitMethodDeclaration(MethodDeclarationSyntax node)
         }
 
         public override void VisitBlock(BlockSyntax node)
+        {
+            VisitBlockStatements(node, node.Statements);
+        }
+
+        private void VisitBlockStatements(SyntaxNode node, IEnumerable<SyntaxNode> statements)
         {
             var tokens = new List<SyntaxToken>();
 
             // We want to collect any variable declarations that are in the block
             // before visiting nested statements
-            foreach (var statement in node.Statements)
+            foreach (var statement in statements)
             {
                 if (statement.Kind() == SyntaxKind.LocalDeclarationStatement)
                 {
@@ -183,6 +188,13 @@ public override void VisitQueryContinuation(QueryContinuationSyntax node)
             _tracker.RemoveIdentifier(node.Identifier);
         }
 
+        public override void VisitSwitchStatement(SwitchStatementSyntax node)
+        {
+            var statements = node.ChildNodes().Where(x => x.IsKind(SyntaxKind.SwitchSection)).SelectMany(x => x.ChildNodes());
+
+            VisitBlockStatements(node, statements);
+        }
+
         public IEnumerable<SyntaxToken> ConflictingTokens
         {
             get