Fix

Author: CyrusNajmabadi

src/Workspaces/CSharp/Portable/CodeGeneration/CSharpSyntaxGenerator.cs

@@ -3188,9 +3188,6 @@ public override SyntaxNode ElementAccessExpression(SyntaxNode expression, IEnume
     internal override SyntaxToken NumericLiteralToken(string text, ulong value)
         => SyntaxFactory.Literal(text, value);
 
-    public override SyntaxNode DefaultExpression(SyntaxNode type)
-        => SyntaxFactory.DefaultExpression((TypeSyntax)type).WithAdditionalAnnotations(Simplifier.Annotation);
-
     private static SyntaxNode Parenthesize(SyntaxNode expression, bool includeElasticTrivia = true, bool addSimplifierAnnotation = true)
         => CSharpSyntaxGeneratorInternal.Parenthesize(expression, includeElasticTrivia, addSimplifierAnnotation);
 

src/Workspaces/Core/Portable/Editing/SyntaxGenerator.cs

@@ -1775,7 +1775,8 @@ internal SyntaxNode InterpolationFormatClause(string format)
     /// An expression that represents the default value of a type.
     /// This is typically a null value for reference types or a zero-filled value for value types.
     /// </summary>
-    public abstract SyntaxNode DefaultExpression(SyntaxNode type);
+    public SyntaxNode DefaultExpression(SyntaxNode type)
+        => this.SyntaxGeneratorInternal.DefaultExpression(type);
 
     public SyntaxNode DefaultExpression(ITypeSymbol type)
         => this.SyntaxGeneratorInternal.DefaultExpression(type);

src/Workspaces/SharedUtilitiesAndExtensions/Workspace/CSharp/LanguageServices/CSharpSyntaxGeneratorInternal.cs

@@ -245,6 +245,9 @@ public override SyntaxNode UnaryPattern(SyntaxToken operatorToken, SyntaxNode pa
     public override SyntaxNode CastExpression(SyntaxNode type, SyntaxNode expression)
         => SyntaxFactory.CastExpression((TypeSyntax)type, (ExpressionSyntax)Parenthesize(expression)).WithAdditionalAnnotations(Simplifier.Annotation);
 
+    public override SyntaxNode DefaultExpression(SyntaxNode type)
+        => SyntaxFactory.DefaultExpression((TypeSyntax)type).WithAdditionalAnnotations(Simplifier.Annotation);
+
     public override SyntaxNode DefaultExpression(ITypeSymbol type)
     {
         // If it's just a reference type, then "null" is the default expression for it.  Note:
@@ -277,7 +280,7 @@ type is IPointerTypeSymbol ||
         }
 
         // Default to a "default(<typename>)" expression.
-        return SyntaxFactory.DefaultExpression(type.GenerateTypeSyntax());
+        return DefaultExpression(type.GenerateTypeSyntax());
     }
 
     public override SyntaxNode TypeExpression(ITypeSymbol typeSymbol, RefKind refKind)

src/Workspaces/SharedUtilitiesAndExtensions/Workspace/Core/LanguageServices/SyntaxGeneratorInternalExtensions/SyntaxGeneratorInternal.cs

@@ -129,6 +129,8 @@ internal static bool ParameterIsScoped(IParameterSymbol symbol)
     #endregion
 
     public abstract SyntaxNode DefaultExpression(ITypeSymbol type);
+    public abstract SyntaxNode DefaultExpression(SyntaxNode type);
+
     public abstract SyntaxNode CastExpression(SyntaxNode type, SyntaxNode expression);
 
     public SyntaxNode CastExpression(ITypeSymbol type, SyntaxNode expression)
@@ -149,8 +151,8 @@ public SyntaxNode MemberAccessExpression(SyntaxNode? expression, SyntaxNode memb
 
     public abstract SyntaxNode MemberAccessExpressionWorker(SyntaxNode? expression, SyntaxNode memberName);
     public abstract SyntaxNode IdentifierName(string identifier);
-    public abstract SyntaxNode ConvertExpression(SyntaxNode type, SyntaxNode expression);
 
+    public abstract SyntaxNode ConvertExpression(SyntaxNode type, SyntaxNode expression);
     public SyntaxNode ConvertExpression(ITypeSymbol type, SyntaxNode expression)
         => ConvertExpression(TypeExpression(type), expression);
 }

src/Workspaces/SharedUtilitiesAndExtensions/Workspace/VisualBasic/LanguageServices/VisualBasicSyntaxGeneratorInternal.vb

@@ -529,6 +529,10 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.CodeGeneration
             Return SyntaxFactory.NothingLiteralExpression(SyntaxFactory.Token(SyntaxKind.NothingKeyword))
         End Function
 
+        Public Overrides Function DefaultExpression(type As SyntaxNode) As SyntaxNode
+            Return SyntaxFactory.NothingLiteralExpression(SyntaxFactory.Token(SyntaxKind.NothingKeyword))
+        End Function
+
         Public Overrides Function IdentifierName(identifier As String) As SyntaxNode
             Return identifier.ToIdentifierName()
         End Function

src/Workspaces/VisualBasic/Portable/CodeGeneration/VisualBasicSyntaxGenerator.vb

@@ -151,10 +151,6 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.CodeGeneration
             Return SyntaxFactory.Literal(text, value)
         End Function
 
-        Public Overrides Function DefaultExpression(type As SyntaxNode) As SyntaxNode
-            Return SyntaxFactory.NothingLiteralExpression(SyntaxFactory.Token(SyntaxKind.NothingKeyword))
-        End Function
-
         Public Overloads Overrides Function ElementAccessExpression(expression As SyntaxNode, arguments As IEnumerable(Of SyntaxNode)) As SyntaxNode
             Return SyntaxFactory.InvocationExpression(VisualBasicSyntaxGeneratorInternal.ParenthesizeLeft(expression), CreateArgumentList(arguments))
         End Function