Fix to pythonas (#19)

Fix ToPythonAs<> so that it always returns an explicit interface
wrapper.

ToPythonAs opts into the converter's behavior that this fork doesn't use
by default, but it is still valid behavior when ToPythonAs is used

Author: koubaa

.gitignore

@@ -36,6 +36,7 @@ coverage.xml
 *.vcxproj.filters
 *.userprefs
 *.DotSettings.user
+.runsettings
 
 # Build results
 [Bb]in/

README.rst

@@ -3,5 +3,7 @@ Ansys fork of `pythonnet <https://github.com/pythonnet/pythonnet>`_.
 We will try to keep this up-to-date with pythonnet and upstream changes that might benefit the pythonnet community
 
 Changes relative to pythonnet:
-- Revert of `#1240 <https://github.com/pythonnet/pythonnet/pull/1240>`_.
-- Enum REPR `#2239 <https://github.com/pythonnet/pythonnet/pull/2239>` is included in this release of version 3.0.2, but is unreleased in pythonnet
+
+* Revert of `#1240 <https://github.com/pythonnet/pythonnet/pull/1240>`_.
+* Enum REPR `#2239 <https://github.com/pythonnet/pythonnet/pull/2239>` is included in this release of version 3.0.2, but is unreleased in pythonnet
+* Opt-into explicit interface wrapping, `#19 <https://github.com/ansys/ansys-pythonnet/pull/19>`. This opts into the behavior that became the default in #1240 if ToPythonAs<T> is explicitly used

src/runtime/Converter.cs

@@ -117,7 +117,9 @@ private static Func<object, bool> GetIsTransparentProxy()
 
         internal static NewReference ToPythonDetectType(object? value)
             => value is null ? new NewReference(Runtime.PyNone) : ToPython(value, value.GetType());
-        internal static NewReference ToPython(object? value, Type type)
+
+
+        internal static NewReference ToPython(object? value, Type type, bool wrapInterface = false)
         {
             if (value is PyObject pyObj)
             {
@@ -144,6 +146,12 @@ internal static NewReference ToPython(object? value, Type type)
                 return CLRObject.GetReference(value, type);
             }
 
+            if (wrapInterface && type.IsInterface)
+            {
+                var ifaceObj = (InterfaceObject)ClassManager.GetClassImpl(type);
+                return ifaceObj.TryWrapObject(value);
+            }
+
             // it the type is a python subclass of a managed type then return the
             // underlying python object rather than construct a new wrapper object.
             if (value is IPythonDerivedType pyderived)
@@ -979,7 +987,7 @@ public static PyObject ToPython(this object? o)
         public static PyObject ToPythonAs<T>(this T? o)
         {
             if (o is null) return Runtime.None;
-            return Converter.ToPython(o, typeof(T)).MoveToPyObject();
+            return Converter.ToPython(o, typeof(T), true).MoveToPyObject();
         }
     }
 }