Add test for enum-based overload resolution (issue #233) (#234)

Add test coverage to verify that overloaded methods with different
enum parameter types dispatch correctly. This confirms that the
existing scoped enum handling already supports overload resolution
via isinstance() type checks.

Changes:
- Add overloaded process(MyEnum) and process(MyEnum2) to enums.hpp
- Declare process methods in enums.pxd
- Add tests verifying correct dispatch and rejection of wrong enum types

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Opus 4.5 <[email protected]>

Author: timosachsenberg

tests/test_code_generator.py

@@ -110,6 +110,18 @@ def test_enums():
     with pytest.raises(AssertionError):
         foo.enumToInt(myenum2_a)
 
+    # Test 5: Overload resolution works correctly for different enum types
+    # The process() method is overloaded: process(MyEnum) and process(MyEnum2)
+    # Python should dispatch to the correct overload based on enum type
+    assert foo.process(mod.Foo.MyEnum.A) == b"MyEnum"
+    assert foo.process(mod.Foo.MyEnum.B) == b"MyEnum"
+    assert foo.process(mod.Foo.MyEnum2.A) == b"MyEnum2"
+    assert foo.process(mod.Foo.MyEnum2.C) == b"MyEnum2"
+
+    # Test 6: Overloaded method rejects wrong enum type from different namespace
+    with pytest.raises(Exception):
+        foo.process(mod.Foo2.MyEnum.A)
+
 
 def test_number_conv():
     target = os.path.join(test_files, "generated", "number_conv.pyx")

tests/test_files/enums.hpp

@@ -15,6 +15,8 @@
  * =============================================================================
  */
 
+#include <string>
+
 // Class with nested scoped enums
 class Foo
 {
@@ -43,6 +45,11 @@ class Foo
        }
        return 0; // unreachable, but silences compiler warning
     };
+
+    // Overloaded methods accepting different enum types - tests overload resolution
+    // Python should correctly dispatch based on the enum type passed
+    std::string process(MyEnum e) { return "MyEnum"; }
+    std::string process(MyEnum2 e) { return "MyEnum2"; }
 };
 
 // Separate namespace with an enum of the same name as Foo::MyEnum

tests/test_files/enums.pxd

@@ -1,4 +1,5 @@
 # cython: language_level=3
+from libcpp.string cimport string as libcpp_string
 #
 # =============================================================================
 # Example: Wrapping C++ Enums in Different Namespaces
@@ -44,6 +45,9 @@ cdef extern from "enums.hpp":
      cdef cppclass Foo:
         # Method accepts Foo_MyEnum (which maps to Foo::MyEnum in C++)
         int enumToInt(Foo_MyEnum e)
+        # Overloaded methods for testing enum-based overload resolution
+        libcpp_string process(Foo_MyEnum e)
+        libcpp_string process(Foo_MyEnum2 e)
 
 cdef extern from "enums.hpp":
      cdef cppclass Foo2: