Fix string -> enum - fixes #476

Author: GrahamTheCoder

CHANGELOG.md

@@ -14,6 +14,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 * Improve numeric casts [#580](https://github.com/icsharpcode/CodeConverter/issues/580)
 * Add ref to conversion of RaiseEvent where needed [#584](https://github.com/icsharpcode/CodeConverter/issues/584)
 * Rename clashing type memvers [#420](https://github.com/icsharpcode/CodeConverter/issues/420)
+* Fix conversion for string implicitly converted to enum [#476](https://github.com/icsharpcode/CodeConverter/issues/476)
 
 ### C# -> VB
 

CodeConverter/CSharp/TypeConversionAnalyzer.cs

@@ -82,6 +82,9 @@ public ExpressionSyntax AddExplicitConversion(Microsoft.CodeAnalysis.VisualBasic
         private ExpressionSyntax AddTypeConversion(VBSyntax.ExpressionSyntax vbNode, ExpressionSyntax csNode, TypeConversionKind conversionKind, bool addParenthesisIfNeeded, ITypeSymbol vbType, ITypeSymbol vbConvertedType)
         {
             switch (conversionKind) {
+                case TypeConversionKind.EnumConversionThenCast:
+                    csNode = AddTypeConversion(vbNode, csNode, TypeConversionKind.Conversion, addParenthesisIfNeeded, vbType, ((INamedTypeSymbol) vbConvertedType).EnumUnderlyingType);
+                    return AddTypeConversion(vbNode, csNode, TypeConversionKind.NonDestructiveCast, addParenthesisIfNeeded, vbType, vbConvertedType);
                 case TypeConversionKind.Unknown:
                 case TypeConversionKind.Identity:
                     return addParenthesisIfNeeded ? VbSyntaxNodeExtensions.ParenthesizeIfPrecedenceCouldChange(vbNode, csNode) : csNode;
@@ -186,7 +189,7 @@ private bool TryAnalyzeCsConversion(Microsoft.CodeAnalysis.VisualBasic.Syntax.Ex
                     return true;
                 }
                 if (isConvertToString || vbConversion.IsNarrowing) {
-                    typeConversionKind = TypeConversionKind.Conversion;
+                    typeConversionKind = vbConvertedType.IsEnumType() && !csConversion.Exists ? TypeConversionKind.EnumConversionThenCast : TypeConversionKind.Conversion;
                     return true;
                 }
             } else if (vbConversion.IsWidening && vbConversion.IsNumeric && csConversion.IsImplicit &&
@@ -309,6 +312,7 @@ public enum TypeConversionKind
             DestructiveCast,
             NonDestructiveCast,
             Conversion,
+            EnumConversionThenCast,
             NullableBool,
             StringToCharArray
         }

Tests/CSharp/TypeCastTests.cs

@@ -7,6 +7,26 @@ namespace ICSharpCode.CodeConverter.Tests.CSharp
 {
     public class TypeCastTests : ConverterTestBase
     {
+        [Fact]
+        public async Task NumericStringToEnumAsync()
+        {
+            await TestConversionVisualBasicToCSharpAsync(
+@"Public Class NumericStringToEnum
+    Public Shared Sub Main()
+        MsgBox(NameOf(Main), ""1"", True)
+    End Sub
+End Class" + Environment.NewLine, @"using Microsoft.VisualBasic; // Install-Package Microsoft.VisualBasic
+using Microsoft.VisualBasic.CompilerServices; // Install-Package Microsoft.VisualBasic
+
+public partial class NumericStringToEnum
+{
+    public static void Main()
+    {
+        Interaction.MsgBox(nameof(Main), (MsgBoxStyle)Conversions.ToInteger(""1""), true);
+    }
+}" + Environment.NewLine);
+        }
+
         [Fact]
         public async Task CIntObjectToIntegerAsync()
         {