VB -> C#: Make interpolated strings interpolated verbatim too

Author: GrahamTheCoder

ICSharpCode.CodeConverter/CSharp/NodesVisitor.cs

@@ -832,7 +832,9 @@ public override CSharpSyntaxNode VisitLiteralExpression(VBSyntax.LiteralExpressi
 
             public override CSharpSyntaxNode VisitInterpolatedStringExpression(VBSyntax.InterpolatedStringExpressionSyntax node)
             {
-                return SyntaxFactory.InterpolatedStringExpression(SyntaxFactory.Token(SyntaxKind.InterpolatedStringStartToken), SyntaxFactory.List(node.Contents.Select(c => (InterpolatedStringContentSyntax)c.Accept(TriviaConvertingVisitor))));
+                var useVerbatim = node.DescendantNodes().OfType<VBSyntax.InterpolatedStringTextSyntax>().Any(c => IsWorthBeingAVerbatimString(c.TextToken.Text));
+                var startTokenKind = useVerbatim ? SyntaxKind.InterpolatedVerbatimStringStartToken : SyntaxKind.InterpolatedStringStartToken;
+                return SyntaxFactory.InterpolatedStringExpression(SyntaxFactory.Token(startTokenKind), SyntaxFactory.List(node.Contents.Select(c => (InterpolatedStringContentSyntax)c.Accept(TriviaConvertingVisitor))));
             }
 
             public override CSharpSyntaxNode VisitInterpolatedStringText(VBSyntax.InterpolatedStringTextSyntax node)

ICSharpCode.CodeConverter/CSharp/VisualBasicConverter.cs

@@ -86,11 +86,7 @@ static Dictionary<string, VariableDeclarationSyntax> SplitVariableDeclarations(V
         internal static ExpressionSyntax GetLiteralExpression(object value, string valueText = null)
         {
             if (value is string s) {
-                var worthBeingAVerbatimString = s.IndexOfAny(new[] { '\r', '\n', '\\' }) > -1;
-                if (worthBeingAVerbatimString) {
-                    var valueWithReplacements = s.Replace("\"", "\"\"");
-                    valueText = $"@\"{valueWithReplacements}\"";
-                }
+                valueText = GetStringValueText(s, valueText);
                 return SyntaxFactory.LiteralExpression(SyntaxKind.StringLiteralExpression,
                     SyntaxFactory.Literal(valueText, s));
             }
@@ -136,6 +132,23 @@ internal static ExpressionSyntax GetLiteralExpression(object value, string value
             throw new ArgumentOutOfRangeException(nameof(value), value, null);
         }
 
+        internal static string GetStringValueText(string s1, string valueText)
+        {
+            var worthBeingAVerbatimString = IsWorthBeingAVerbatimString(s1);
+            if (worthBeingAVerbatimString)
+            {
+                var valueWithReplacements = s1.Replace("\"", "\"\"");
+                valueText = $"@\"{valueWithReplacements}\"";
+            }
+
+            return valueText;
+        }
+
+        internal static bool IsWorthBeingAVerbatimString(string s1)
+        {
+            return s1.IndexOfAny(new[] {'\r', '\n', '\\'}) > -1;
+        }
+
         /// <summary>
         ///  https://docs.microsoft.com/en-us/dotnet/visual-basic/programming-guide/language-features/data-types/type-characters
         //   https://stackoverflow.com/a/166762/1128762

Tests/CSharp/ExpressionTests.cs

@@ -11,13 +11,17 @@ public void MultilineString()
             TestConversionVisualBasicToCSharpWithoutComments(@"Class TestClass
     Private Sub TestMethod()
         Dim x = ""Hello\ All strings in VB are verbatim """" < that's just a single escaped quote
+World!""
+        Dim y = $""Hello\ All strings in VB are verbatim """" < that's just a single escaped quote
 World!""
     End Sub
 End Class", @"class TestClass
 {
     private void TestMethod()
     {
         var x = @""Hello\ All strings in VB are verbatim """" < that's just a single escaped quote
+World!"";
+        var y = $@""Hello\ All strings in VB are verbatim """" < that's just a single escaped quote
 World!"";
     }
 }");