Add tests for py3 enums

Author: aldanor

tests/conftest.py

@@ -200,6 +200,7 @@ def pytest_namespace():
     except ImportError:
         have_eigen = False
     pypy = platform.python_implementation() == "PyPy"
+    py3 = sys.version_info.major == 3
 
     skipif = pytest.mark.skipif
     return {
@@ -211,7 +212,8 @@ def pytest_namespace():
         'requires_eigen_and_scipy': skipif(not have_eigen or not scipy,
                                            reason="eigen and/or scipy are not installed"),
         'unsupported_on_pypy': skipif(pypy, reason="unsupported on PyPy"),
-        'gc_collect': gc_collect
+        'gc_collect': gc_collect,
+        'requires_py3': skipif(not py3, reason='requires Python 3')
     }
 
 

tests/test_enum.cpp

@@ -37,6 +37,23 @@ class ClassWithUnscopedEnum {
     }
 };
 
+enum Py3Enum {
+    A = -42,
+    B = 1,
+    C = 42,
+};
+
+enum class Py3EnumScoped : short {
+    X = 10,
+    Y = -1024,
+};
+
+enum class Py3EnumEmpty {};
+
+enum class Py3EnumNonUnique {
+    X = 1
+};
+
 std::string test_scoped_enum(ScopedEnum z) {
     return "ScopedEnum::" + std::string(z == ScopedEnum::Two ? "Two" : "Three");
 }
@@ -59,6 +76,33 @@ test_initializer enums([](py::module &m) {
         .value("Execute", Flags::Execute)
         .export_values();
 
+#if PY_VERSION_HEX >= 0x03000000
+    py::py3_enum<Py3EnumEmpty>(m, "Py3EnumEmpty");
+
+    py::py3_enum<Py3Enum>(m, "Py3Enum")
+        .value("A", Py3Enum::A)
+        .value("B", Py3Enum::B)
+        .value("C", Py3Enum::C);
+
+    py::py3_enum<Py3EnumScoped>(m, "Py3EnumScoped")
+        .value("X", Py3EnumScoped::X)
+        .value("Y", Py3EnumScoped::Y);
+
+    m.def("make_py3_enum", [](bool x) {
+        return x ? Py3EnumScoped::X : Py3EnumScoped::Y;
+    });
+
+    m.def("take_py3_enum", [](Py3EnumScoped x) {
+        return x == Py3EnumScoped::X;
+    });
+
+    m.def("non_unique_py3_enum", [=]() {
+        py::py3_enum<Py3EnumNonUnique>(m, "Py3EnumNonUnique")
+            .value("X", Py3EnumNonUnique::X)
+            .value("Y", Py3EnumNonUnique::X);
+    });
+#endif
+
     py::class_<ClassWithUnscopedEnum> exenum_class(m, "ClassWithUnscopedEnum");
     exenum_class.def_static("test_function", &ClassWithUnscopedEnum::test_function);
     py::enum_<ClassWithUnscopedEnum::EMode>(exenum_class, "EMode")

tests/test_enum.py

@@ -115,3 +115,33 @@ def test_binary_operators():
     state2 = ~state
     assert state2 == -7
     assert int(state ^ state2) == -1
+
+
+@pytest.requires_py3
+def test_py3_enum():
+    from pybind11_tests import (
+        Py3Enum, Py3EnumEmpty, Py3EnumScoped,
+        make_py3_enum, take_py3_enum, non_unique_py3_enum
+    )
+
+    from enum import IntEnum
+
+    expected = {
+        Py3Enum: [('A', -42), ('B', 1), ('C', 42)],
+        Py3EnumEmpty: [],
+        Py3EnumScoped: [('X', 10), ('Y', -1024)]
+    }
+
+    for tp, entries in expected.items():
+        assert issubclass(tp, IntEnum)
+        assert sorted(tp.__members__.items()) == entries
+
+    assert make_py3_enum(True) is Py3EnumScoped.X
+    assert make_py3_enum(False) is Py3EnumScoped.Y
+
+    assert take_py3_enum(Py3EnumScoped.X)
+    assert not take_py3_enum(Py3EnumScoped.Y)
+
+    with pytest.raises(ValueError) as excinfo:
+        non_unique_py3_enum()
+    assert 'duplicate values found' in str(excinfo.value)