From 8ea6d0d730bc4b74b5d1a9b08e01f0bf0346812c Mon Sep 17 00:00:00 2001
From: Robert Clipsham <robert@octarineparrot.com>
Date: Thu, 18 Apr 2019 10:36:06 +0100
Subject: [PATCH] Do not output private get/set for interfaces

Closes #270

# Conflicts:
#	ICSharpCode.CodeConverter/CSharp/NodesVisitor.cs
---
 ICSharpCode.CodeConverter/CSharp/NodesVisitor.cs | 13 ++++++++++---
 Tests/CSharp/MemberTests.cs                      | 16 +++++++++++++++-
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/ICSharpCode.CodeConverter/CSharp/NodesVisitor.cs b/ICSharpCode.CodeConverter/CSharp/NodesVisitor.cs
index 34632dd4b..6a6ab669a 100644
--- a/ICSharpCode.CodeConverter/CSharp/NodesVisitor.cs
+++ b/ICSharpCode.CodeConverter/CSharp/NodesVisitor.cs
@@ -455,6 +455,7 @@ public override CSharpSyntaxNode VisitPropertyStatement(VBSyntax.PropertyStateme
                 var modifiers = CommonConversions.ConvertModifiers(convertibleModifiers, GetMemberContext(node));
                 var isIndexer = node.Modifiers.Any(m => SyntaxTokenExtensions.IsKind(m, VBasic.SyntaxKind.DefaultKeyword));
                 var accessedThroughMyClass = IsAccessedThroughMyClass(node, node.Identifier, _semanticModel.GetDeclaredSymbol(node));
+                bool isInInterface = node.Ancestors().OfType<VBSyntax.InterfaceBlockSyntax>().FirstOrDefault() != null;
 
                 var initializer = (EqualsValueClauseSyntax)node.Initializer?.Accept(TriviaConvertingVisitor);
                 var rawType = (TypeSyntax)node.AsClause?.TypeSwitch(
@@ -476,9 +477,15 @@ public override CSharpSyntaxNode VisitPropertyStatement(VBSyntax.PropertyStateme
                     if (isReadonly) {
                         setAccessor = setAccessor.AddModifiers(SyntaxFactory.Token(SyntaxKind.PrivateKeyword));
                     }
-                    // In VB, there's a backing field which can always be read and written to even on ReadOnly/WriteOnly properties.
-                    // Our conversion will rewrite usages of that field to use the property accessors which therefore must exist and be private at minimum.
-                    accessors = SyntaxFactory.AccessorList(SyntaxFactory.List(new[] {getAccessor, setAccessor}));
+                    if (isInInterface && isReadonly) {
+                        accessors = SyntaxFactory.AccessorList(SyntaxFactory.List(new[] { getAccessor }));
+                    } else if (isInInterface && isWriteOnly) {
+                        accessors = SyntaxFactory.AccessorList(SyntaxFactory.List(new[] { setAccessor }));
+                    } else {
+                        // In VB, there's a backing field which can always be read and written to even on ReadOnly/WriteOnly properties.
+                        // Our conversion will rewrite usages of that field to use the property accessors which therefore must exist and be private at minimum.
+                        accessors = SyntaxFactory.AccessorList(SyntaxFactory.List(new[] { getAccessor, setAccessor }));
+                    }
                 } else {
                     accessors = SyntaxFactory.AccessorList(
                         SyntaxFactory.List(
diff --git a/Tests/CSharp/MemberTests.cs b/Tests/CSharp/MemberTests.cs
index b47aa3f87..d0c6cff8a 100644
--- a/Tests/CSharp/MemberTests.cs
+++ b/Tests/CSharp/MemberTests.cs
@@ -321,6 +321,20 @@ public int Test3
 }");
         }
 
+        [Fact]
+        public void TestReadWriteOnlyInterfaceProperty()
+        {
+            TestConversionVisualBasicToCSharpWithoutComments(
+@"Public Interface Foo
+    ReadOnly Property P1() As String
+    WriteOnly Property P2() As String
+End Interface", @"public interface Foo
+{
+    string P1 { get; }
+    string P2 { set; }
+}");
+        }
+
         [Fact]
         public void TestConstructor()
         {
@@ -1259,7 +1273,7 @@ public void TestWriteOnlyProperties()
     WriteOnly Property Items As Integer()
 End Interface", @"interface TestInterface
 {
-    int[] Items { private get; set; }
+    int[] Items { set; }
 }");
         }