VB -> C#: Qualify name in case of type promotion - fixes #179

Author: GrahamTheCoder

ICSharpCode.CodeConverter/CSharp/NodesVisitor.cs

@@ -1041,6 +1041,9 @@ public override CSharpSyntaxNode VisitMemberAccessExpression(VBSyntax.MemberAcce
                         return SyntaxFactory.MemberBindingExpression(simpleNameSyntax);
                     }
                     left = SyntaxFactory.IdentifierName(_withBlockTempVariableNames.Peek());
+                } else if (TryGetTypePromotedModuleSymbol(node, out var promotedModuleSymbol)) {
+                    left = SyntaxFactory.MemberAccessExpression(SyntaxKind.SimpleMemberAccessExpression, left,
+                        SyntaxFactory.IdentifierName(promotedModuleSymbol.Name));
                 }
 
                 if (node.Expression.IsKind(VBasic.SyntaxKind.GlobalName)) {
@@ -1056,6 +1059,22 @@ public override CSharpSyntaxNode VisitMemberAccessExpression(VBSyntax.MemberAcce
                 return memberAccessExpressionSyntax;
             }
 
+            /// <remarks>https://docs.microsoft.com/en-us/dotnet/visual-basic/programming-guide/language-features/declared-elements/type-promotion</remarks>
+            private bool TryGetTypePromotedModuleSymbol(VBSyntax.MemberAccessExpressionSyntax node, out INamedTypeSymbol moduleSymbol)
+            {
+                if (_semanticModel.GetSymbolInfo(node.Expression).ExtractBestMatch() is INamespaceSymbol
+                        expressionSymbol &&
+                    _semanticModel.GetSymbolInfo(node.Name).ExtractBestMatch().ContainingSymbol is INamedTypeSymbol
+                        nameContainingSymbol &&
+                    nameContainingSymbol.ContainingSymbol.Equals(expressionSymbol)) {
+                    moduleSymbol = nameContainingSymbol;
+                    return true;
+                }
+
+                moduleSymbol = null;
+                return false;
+            }
+
             private static bool IsSubPartOfConditionalAccess(VBSyntax.MemberAccessExpressionSyntax node)
             {
                 var firstPossiblyConditionalAncestor = node.Parent;

Tests/CSharp/ExpressionTests.cs

@@ -1169,6 +1169,39 @@ public void TestMethod(string dir)
     }
 }");
         }
+
+        [Fact]
+        public void TypePromotedModuleIsQualified()
+        {
+            TestConversionVisualBasicToCSharp(@"Namespace TestNamespace
+    Public Module TestModule
+        Public Sub ModuleFunction()
+        End Sub
+    End Module
+End Namespace
+
+Class TestClass
+    Public Sub TestMethod(dir As String)
+        TestNamespace.ModuleFunction()
+    End Sub
+End Class", @"namespace TestNamespace
+{
+    public static class TestModule
+    {
+        public static void ModuleFunction()
+        {
+        }
+    }
+}
+
+class TestClass
+{
+    public void TestMethod(string dir)
+    {
+        TestNamespace.TestModule.ModuleFunction();
+    }
+}");
+        }
 
         [Fact]
         public void NameQualifyingHandlesInheritance()