Add tests

Author: sergey-miryanov

Lib/test/test_capi/test_type.py

@@ -274,3 +274,10 @@ def test_extension_managed_dict_type(self):
         obj.__dict__ = {'bar': 3}
         self.assertEqual(obj.__dict__, {'bar': 3})
         self.assertEqual(obj.bar, 3)
+
+    def test_extension_managed_weakref_nogc_type(self):
+        msg = ("type _testcapi.ManagedWeakrefNoGCType "
+               "has the Py_TPFLAGS_MANAGED_WEAKREF "
+               "flag but not Py_TPFLAGS_HAVE_GC flag")
+        with self.assertRaisesRegex(SystemError, msg):
+            _testcapi.create_managed_weakref_nogc_type()

Modules/_testcapimodule.c

@@ -2562,6 +2562,39 @@ toggle_reftrace_printer(PyObject *ob, PyObject *arg)
     Py_RETURN_NONE;
 }
 
+
+typedef struct {
+    PyObject_HEAD
+} ManagedWeakrefNoGCObject;
+
+static void
+ManagedWeakrefNoGC_dealloc(PyObject *self)
+{
+    PyObject_ClearWeakRefs(self);
+    PyTypeObject *tp = Py_TYPE(self);
+    tp->tp_free(self);
+    Py_DECREF(tp);
+}
+
+static PyType_Slot ManagedWeakrefNoGC_slots[] = {
+    {Py_tp_dealloc, ManagedWeakrefNoGC_dealloc},
+    {0, 0}
+};
+
+static PyType_Spec ManagedWeakrefNoGC_spec = {
+    .name = "_testcapi.ManagedWeakrefNoGCType",
+    .basicsize = sizeof(ManagedWeakrefNoGCObject),
+    .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_MANAGED_WEAKREF),
+    .slots = ManagedWeakrefNoGC_slots,
+};
+
+static PyObject *
+test_create_managed_weakref_nogc_type(PyObject *self, PyObject *Py_UNUSED(args))
+{
+    return PyType_FromSpec(&ManagedWeakrefNoGC_spec);
+}
+
+
 static PyMethodDef TestMethods[] = {
     {"set_errno",               set_errno,                       METH_VARARGS},
     {"test_config",             test_config,                     METH_NOARGS},
@@ -2656,6 +2689,8 @@ static PyMethodDef TestMethods[] = {
     {"test_atexit", test_atexit, METH_NOARGS},
     {"code_offset_to_line", _PyCFunction_CAST(code_offset_to_line), METH_FASTCALL},
     {"toggle_reftrace_printer", toggle_reftrace_printer, METH_O},
+    {"create_managed_weakref_nogc_type",
+        test_create_managed_weakref_nogc_type, METH_NOARGS},
     {NULL, NULL} /* sentinel */
 };