Change name generating implementation

src/Features/CSharp/Portable/ExtractMethod/CSharpMethodExtractor.CSharpCodeGenerator.ExpressionCodeGenerator.cs

@@ -41,7 +41,7 @@ protected override SyntaxToken CreateMethodName(bool localFunction)
 
                     var semanticModel = this.SemanticDocument.SemanticModel;
                     var nameGenerator = new UniqueNameGenerator(semanticModel);
-                    return SyntaxFactory.Identifier(nameGenerator.CreateUniqueMethodName(containingScope, methodName, localFunction));
+                    return SyntaxFactory.Identifier(nameGenerator.CreateUniqueMethodName(containingScope, methodName));
                 }
 
                 private static string GetMethodNameBasedOnExpression(string methodName, SyntaxNode expression)

src/Features/CSharp/Portable/ExtractMethod/CSharpMethodExtractor.CSharpCodeGenerator.MultipleStatementsCodeGenerator.cs

@@ -47,7 +47,14 @@ protected override SyntaxToken CreateMethodName(bool localFunction)
                     var semanticModel = this.SemanticDocument.SemanticModel;
                     var nameGenerator = new UniqueNameGenerator(semanticModel);
                     var scope = this.CSharpSelectionResult.GetContainingScope();
-                    return SyntaxFactory.Identifier(nameGenerator.CreateUniqueMethodName(scope, "NewMethod", localFunction));
+
+                    // If extracting a local function, we want to ensure all local variables are considered when generating a unique name.
+                    if (localFunction)
+                    {
+                        scope = this.CSharpSelectionResult.GetFirstTokenInSelection().Parent;
+                    }
+
+                    return SyntaxFactory.Identifier(nameGenerator.CreateUniqueMethodName(scope, "NewMethod"));
                 }
 
                 protected override IEnumerable<StatementSyntax> GetInitialStatementsForMethodDefinitions()

src/Features/CSharp/Portable/ExtractMethod/CSharpMethodExtractor.CSharpCodeGenerator.SingleStatementCodeGenerator.cs

@@ -39,7 +39,14 @@ protected override SyntaxToken CreateMethodName(bool localFunction)
                     var semanticModel = this.SemanticDocument.SemanticModel;
                     var nameGenerator = new UniqueNameGenerator(semanticModel);
                     var scope = this.CSharpSelectionResult.GetContainingScope();
-                    return SyntaxFactory.Identifier(nameGenerator.CreateUniqueMethodName(scope, "NewMethod", localFunction));
+
+                    // If extracting a local function, we want to ensure all local variables are considered when generating a unique name.
+                    if (localFunction)
+                    {
+                        scope = this.CSharpSelectionResult.GetFirstTokenInSelection().Parent;
+                    }
+
+                    return SyntaxFactory.Identifier(nameGenerator.CreateUniqueMethodName(scope, "NewMethod"));
                 }
 
                 protected override IEnumerable<StatementSyntax> GetInitialStatementsForMethodDefinitions()

src/Features/Core/Portable/ExtractMethod/UniqueNameGenerator.cs

@@ -16,23 +16,11 @@ public UniqueNameGenerator(SemanticModel semanticModel)
             _semanticModel = semanticModel;
         }
 
-        public string CreateUniqueMethodName(SyntaxNode contextNode, string baseName, bool localFunction = false)
+        public string CreateUniqueMethodName(SyntaxNode contextNode, string baseName)
         {
             Contract.ThrowIfNull(contextNode);
             Contract.ThrowIfNull(baseName);
 
-            if (localFunction)
-            {
-                // When generating local functions, we also want to take into account the names of local variables.
-                var childNodes = contextNode.ChildNodes().AsArray();
-                if (childNodes.Length > 0)
-                {
-                    // If we take the first child node, we may end up with part of the method header.
-                    // To be safe, we use the last child node, which is guaranteed to be part of the context method's body.
-                    contextNode = (SyntaxNode)childNodes.GetValue(childNodes.Length - 1);
-                }
-            }
-
             return NameGenerator.GenerateUniqueName(baseName, string.Empty,
                 n => _semanticModel.LookupSymbols(contextNode.SpanStart, container: null, n).Length == 0);
         }