gh-102251: add missing cleanups for test_import

Lib/test/libregrtest/main.py

@@ -213,6 +213,13 @@ def parse_args(self, kwargs):
         if ns.tempdir:
             ns.tempdir = os.path.expanduser(ns.tempdir)
 
+        # introduce a way to skip the ref leak tests
+        if ns.huntrleaks:
+            if ns.ignore_tests is None:
+                ns.ignore_tests = ["*skip_ref_leak_test"]
+            else:
+                ns.ignore_tests.append("*skip_ref_leak_test")
+
         self.ns = ns
 
     def find_tests(self, tests):

Lib/test/test_import/__init__.py

@@ -1980,10 +1980,6 @@ class SinglephaseInitTests(unittest.TestCase):
 
     @classmethod
     def setUpClass(cls):
-        if '-R' in sys.argv or '--huntrleaks' in sys.argv:
-            # https://github.com/python/cpython/issues/102251
-            raise unittest.SkipTest('unresolved refleaks (see gh-102251)')
-
         spec = importlib.util.find_spec(cls.NAME)
         from importlib.machinery import ExtensionFileLoader
         cls.FILE = spec.origin
@@ -2330,6 +2326,8 @@ def test_variants(self):
             self.assertIs(basic.look_up_self(), basic_lookedup)
             self.assertEqual(basic.initialized_count(), expected_init_count)
 
+            loaded.module._clear_module_state()
+
     def test_basic_reloaded(self):
         # m_copy is copied into the existing module object.
         # Global state is not changed.
@@ -2413,6 +2411,11 @@ def test_with_reinit_reloaded(self):
 
                 self.assertIs(reloaded.snapshot.cached, reloaded.module)
 
+                if hasattr(loaded.module, '_clear_module_state'):
+                    loaded.module._clear_module_state()
+                if hasattr(reloaded.module, '_clear_module_state'):
+                    reloaded.module._clear_module_state()
+
     # Currently, for every single-phrase init module loaded
     # in multiple interpreters, those interpreters share a
     # PyModuleDef for that object, which can be a problem.
@@ -2488,7 +2491,7 @@ def test_basic_multiple_interpreters_main_no_reset(self):
         #  * module's global state was updated, not reset
 
     @requires_subinterpreters
-    def test_basic_multiple_interpreters_deleted_no_reset(self):
+    def test_basic_multiple_interpreters_deleted_no_reset_skip_ref_leak_test(self):
         # without resetting; already loaded in a deleted interpreter
 
         # At this point:

Modules/_testsinglephase.c

@@ -248,6 +248,24 @@ basic__clear_globals(PyObject *self, PyObject *Py_UNUSED(ignored))
      basic__clear_globals_doc}
 
 
+PyDoc_STRVAR(basic__clear_module_state_doc, "_clear_module_state()\n\
+\n\
+Free the module state and set it to uninitialized.");
+
+static PyObject*
+basic__clear_module_state(PyObject *self, PyObject *Py_UNUSED(ignored)) {
+    module_state *state = get_module_state(self);
+    if (state != NULL) {
+        clear_state(state);
+    }
+    Py_RETURN_NONE;
+}
+
+#define _CLEAR_MODULE_STATE_METHODDEF \
+    {"_clear_module_state", basic__clear_module_state, METH_NOARGS, \
+     basic__clear_module_state_doc}
+
+
 /*********************************************/
 /* the _testsinglephase module (and aliases) */
 /*********************************************/
@@ -408,7 +426,7 @@ PyInit__testsinglephase_with_reinit(void)
 /* the _testsinglephase_with_state module */
 /******************************************/
 
-/* This ia less typical of legacy extensions in the wild:
+/* This is a less typical of legacy extensions in the wild:
    - single-phase init  (same as _testsinglephase above)
    - has some module state
    - supports repeated initialization
@@ -424,6 +442,7 @@ static PyMethodDef TestMethods_WithState[] = {
     LOOK_UP_SELF_METHODDEF,
     SUM_METHODDEF,
     STATE_INITIALIZED_METHODDEF,
+    _CLEAR_MODULE_STATE_METHODDEF,
     {NULL, NULL}           /* sentinel */
 };