Add extraction of ExpressionStatement to refa helpers.

src/Features/Core/Portable/CodeRefactorings/AbstractRefactoringHelpersService.cs

@@ -365,6 +365,20 @@ protected virtual IEnumerable<SyntaxNode> ExtractNodesSimple(SyntaxNode node, IS
                 syntaxFacts.GetPartsOfAssignmentExpressionOrStatement(node, out _, out _, out var rightSide);
                 yield return rightSide;
             }
+
+            // `a();`
+            // -> a()
+            if (syntaxFacts.IsExpressionStatement(node))
+            {
+                yield return syntaxFacts.GetExpressionOfExpressionStatement(node);
+            }
+
+            // `a()`;
+            // -> `a();`
+            if (node.Parent != null && syntaxFacts.IsExpressionStatement(node.Parent))
+            {
+                yield return node.Parent;
+            }
         }
 
         /// <summary>

src/Features/Core/Portable/IntroduceVariable/IntroduceLocalForExpressionCodeRefactoringProvider.cs

@@ -58,14 +58,6 @@ public sealed override async Task ComputeRefactoringsAsync(CodeRefactoringContex
         protected async Task<TExpressionStatementSyntax> GetExpressionStatementAsync(CodeRefactoringContext context)
         {
             var expressionStatement = await context.TryGetRelevantNodeAsync<TExpressionStatementSyntax>().ConfigureAwait(false);
-            if (expressionStatement == null)
-            {
-                // If an expression-statement wasn't selected, see if they're selecting
-                // an expression belonging to an expression-statement instead.
-                var expression = await context.TryGetRelevantNodeAsync<TExpressionSyntax>().ConfigureAwait(false);
-                expressionStatement = expression?.Parent as TExpressionStatementSyntax;
-            }
-
             return expressionStatement != null && IsValid(expressionStatement, context.Span)
                 ? expressionStatement
                 : null;

src/Workspaces/CSharp/Portable/LanguageServices/CSharpSyntaxKindsService.cs

@@ -28,5 +28,7 @@ private CSharpSyntaxKindsService()
         public override int UsingStatement => (int)SyntaxKind.UsingStatement;
         public override int ReturnStatement => (int)SyntaxKind.ReturnStatement;
         public override int HashToken => (int)SyntaxKind.HashToken;
+
+        public override int ExpressionStatement => (int)SyntaxKind.ExpressionStatement;
     }
 }

src/Workspaces/Core/Portable/LanguageServices/SyntaxFactsService/AbstractSyntaxFactsService.cs

@@ -571,5 +571,8 @@ public bool IsUsingStatement(SyntaxNode node)
 
         public bool IsReturnStatement(SyntaxNode node)
             => node.RawKind == SyntaxKinds.ReturnStatement;
+
+        public bool IsExpressionStatement(SyntaxNode node)
+            => node.RawKind == SyntaxKinds.ExpressionStatement;
     }
 }

src/Workspaces/Core/Portable/LanguageServices/SyntaxFactsService/ISyntaxFactsService.cs

@@ -105,6 +105,8 @@ internal interface ISyntaxFactsService : ILanguageService
         bool IsTrueLiteralExpression(SyntaxNode node);
         bool IsThisExpression(SyntaxNode node);
         bool IsBaseExpression(SyntaxNode node);
+        bool IsExpressionStatement(SyntaxNode node);
+
 
         string GetText(int kind);
         bool IsInInactiveRegion(SyntaxTree syntaxTree, int position, CancellationToken cancellationToken);

src/Workspaces/Core/Portable/LanguageServices/SyntaxFactsService/ISyntaxKindsService.cs

@@ -33,6 +33,7 @@ internal interface ISyntaxKindsService : ILanguageService
         int UsingStatement { get; }
         int ReturnStatement { get; }
         int HashToken { get; }
+        int ExpressionStatement { get; }
     }
 
     internal abstract class AbstractSyntaxKindsService : ISyntaxKindsService
@@ -53,5 +54,6 @@ internal abstract class AbstractSyntaxKindsService : ISyntaxKindsService
         public abstract int UsingStatement { get; }
         public abstract int ReturnStatement { get; }
         public abstract int HashToken { get; }
+        public abstract int ExpressionStatement { get; }
     }
 }

src/Workspaces/VisualBasic/Portable/LanguageServices/VisualBasicSyntaxFactsService.vb

@@ -2037,5 +2037,9 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
 
             Return IsOnHeader(position, node, node.ForEachStatement)
         End Function
+
+        Private Function ISyntaxFactsService_IsExpressionStatement(node As SyntaxNode) As Boolean Implements ISyntaxFactsService.IsExpressionStatement
+            Return MyBase.IsExpressionStatement(node)
+        End Function
     End Class
 End Namespace

src/Workspaces/VisualBasic/Portable/LanguageServices/VisualBasicSyntaxKindsService.vb

@@ -28,5 +28,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.LanguageServices
         Public Overrides ReadOnly Property UsingStatement As Integer = SyntaxKind.UsingStatement
         Public Overrides ReadOnly Property ReturnStatement As Integer = SyntaxKind.ReturnStatement
         Public Overrides ReadOnly Property HashToken As Integer = SyntaxKind.HashToken
+
+        Public Overrides ReadOnly Property ExpressionStatement As Integer = SyntaxKind.ExpressionStatement
     End Class
 End Namespace