Move pybind11-utils to own folder. Add tests for shared_cpp_owner.

tests/python/test_shared_cpp_owner.py

@@ -0,0 +1,77 @@
+from re import A
+
+import pytest
+from PyQt6.QtCore import QDateTime, Qt
+
+m = pytest.importorskip("mobase_tests.shared_cpp_owner")
+
+
+class PyBase(m.Base):
+    def __init__(self, name: str, value: int):
+        super().__init__(name)
+        self.value = value
+
+    def fn(self):
+        return f"PyBase.fn({self.value})"
+
+
+def test_shared_cpp_owner_1():
+    # create from C++, owned by Python
+
+    # create from C++
+    p = m.create("tmp")
+    assert m.is_alive("tmp")
+
+    # should delete since it's not owner by C++
+    del p
+    assert not m.is_alive("tmp")
+
+
+def test_shared_cpp_owner_2():
+    # create from C++, owned by C++ (and Python)
+
+    # create from C++
+    p = m.create_and_store("tmp")
+    assert m.is_alive("tmp")
+
+    # should not delete since it's owned by both C++ and Python
+    del p
+    assert m.is_alive("tmp")
+
+    # clear from C++ should free it
+    m.clear()
+    assert not m.is_alive("tmp")
+
+
+def test_shared_cpp_owner_3():
+    # create from Python, owned by Python
+
+    p = PyBase("foo", 1)
+    assert m.is_alive("foo")
+    assert m.call_fn("foo") == "PyBase.fn(1)"
+
+    del p
+    assert not m.is_alive("foo")
+
+
+def test_shared_cpp_owner_3():
+    # create from Python, owned by C++
+
+    p = PyBase("foo", 2)
+    assert m.is_alive("foo")
+
+    # send to C++
+    m.store(p)
+    assert m.is_alive("foo")
+    assert m.call_fn("foo") == "PyBase.fn(2)"
+
+    # delete in Python, should still be alived
+    del p
+    assert m.is_alive("foo")
+
+    # should still be able to call fn()
+    assert m.call_fn("foo") == "PyBase.fn(2)"
+
+    # clear in C++, should kill Python
+    m.clear()
+    assert not m.is_alive("foo")