C# -> VB: Convert interpolation format and alignment - fixes #255

Author: GrahamTheCoder

ICSharpCode.CodeConverter/CSharp/NodesVisitor.cs

@@ -1052,7 +1052,7 @@ public override CSharpSyntaxNode VisitInterpolationAlignmentClause(VBSyntax.Inte
             public override CSharpSyntaxNode VisitInterpolationFormatClause(VBSyntax.InterpolationFormatClauseSyntax node)
             {
                 SyntaxToken formatStringToken = SyntaxFactory.Token(SyntaxTriviaList.Empty, SyntaxKind.InterpolatedStringTextToken, node.FormatStringToken.Text, node.FormatStringToken.ValueText, SyntaxTriviaList.Empty);
-                return SyntaxFactory.InterpolationFormatClause(SyntaxFactory.Token(SyntaxKind.ColonToken).WithTriviaFrom(node.ColonToken), formatStringToken);
+                return SyntaxFactory.InterpolationFormatClause(SyntaxFactory.Token(SyntaxKind.ColonToken), formatStringToken);
             }
 
             public override CSharpSyntaxNode VisitMeExpression(VBSyntax.MeExpressionSyntax node)

ICSharpCode.CodeConverter/VB/NodesVisitor.cs

@@ -770,12 +770,19 @@ public override VisualBasicSyntaxNode VisitInterpolatedStringText(CSS.Interpolat
 
         public override VisualBasicSyntaxNode VisitInterpolation(CSS.InterpolationSyntax node)
         {
-            return SyntaxFactory.Interpolation((ExpressionSyntax)node.Expression.Accept(TriviaConvertingVisitor));
+            return SyntaxFactory.Interpolation(SyntaxFactory.Token(SyntaxKind.OpenBraceToken), (ExpressionSyntax) node.Expression.Accept(TriviaConvertingVisitor), (InterpolationAlignmentClauseSyntax) node.AlignmentClause?.Accept(TriviaConvertingVisitor), (InterpolationFormatClauseSyntax) node.FormatClause?.Accept(TriviaConvertingVisitor), SyntaxFactory.Token(SyntaxKind.CloseBraceToken));
         }
 
         public override VisualBasicSyntaxNode VisitInterpolationFormatClause(CSS.InterpolationFormatClauseSyntax node)
         {
-            return base.VisitInterpolationFormatClause(node);
+            SyntaxToken formatStringToken = SyntaxFactory.InterpolatedStringTextToken(SyntaxTriviaList.Empty,
+                node.FormatStringToken.Text, node.FormatStringToken.ValueText, SyntaxTriviaList.Empty);
+            return SyntaxFactory.InterpolationFormatClause(SyntaxFactory.Token(SyntaxKind.ColonToken), formatStringToken);
+        }
+
+        public override VisualBasicSyntaxNode VisitInterpolationAlignmentClause(CSS.InterpolationAlignmentClauseSyntax node)
+        {
+            return SyntaxFactory.InterpolationAlignmentClause(SyntaxFactory.Token(SyntaxKind.CommaToken), (ExpressionSyntax)node.Value.Accept(TriviaConvertingVisitor));
         }
 
         public override VisualBasicSyntaxNode VisitParenthesizedExpression(CSS.ParenthesizedExpressionSyntax node)

Tests/VB/ExpressionTests.cs

@@ -23,6 +23,44 @@ End Sub
 End Class");
         }
 
+
+        [Fact]
+        public void StringInterpolationWithDoubleQuotes()
+        {
+            TestConversionCSharpToVisualBasic(
+                @"using System;
+
+namespace Global.InnerNamespace
+{
+    public class Test
+    {
+        public string StringInter(string t, DateTime dt)
+        {
+            var a = $""pre{t} t"";
+            var b = $""pre{t} \"" t"";
+            var c = $@""pre{t} """"\ t"";
+            var e = $@""pre{t + ""\""""} """"\ t"";
+            var f = $""pre{{escapedBraces}}{dt,4:hh}"";
+            return a + b + c + d + e + f;
+        }
+    }
+}",
+                @"Imports System
+
+Namespace [Global].InnerNamespace
+    Public Class Test
+        Public Function StringInter(ByVal t As String, ByVal dt As DateTime) As String
+            Dim a = $""pre{t} t""
+            Dim b = $""pre{t} """" t""
+            Dim c = $""pre{t} """"\ t""
+            Dim e = $""pre{t & """"""""} """"\ t""
+            Dim f = $""pre{{escapedBraces}}{dt,4:hh}""
+            Return a & b & c & d & e & f
+        End Function
+    End Class
+End Namespace");
+        }
+
         [Fact]
         public void ConditionalExpression()
         {