bpo-41780: Fix __dir__ of types.GenericAlias (GH-22262)

Automerge-Triggered-By: @gvanrossum

diff --git a/Lib/test/test_genericalias.py b/Lib/test/test_genericalias.py
index 1f24469471428afe6dba72203d7d360cdd497e54..643fffc073e82f3e2524d64c59f58bd2469848c8 100644 (file)
--- a/Lib/test/test_genericalias.py
+++ b/Lib/test/test_genericalias.py
@@ -287,6 +287,11 @@ class BaseTest(unittest.TestCase):
         self.assertEqual(a.__args__, (list[T], tuple[T, ...]))
         self.assertEqual(a.__parameters__, (T,))
 
+    def test_dir(self):
+        dir_of_gen_alias = set(dir(list[int]))
+        self.assertTrue(dir_of_gen_alias.issuperset(dir(list)))
+        for generic_alias_property in ("__origin__", "__args__", "__parameters__"):
+            self.assertIn(generic_alias_property, dir_of_gen_alias)
 
 if __name__ == "__main__":
     unittest.main()

diff --git a/Misc/NEWS.d/next/Core and Builtins/2020-09-15-23-29-49.bpo-41780.bOBUIH.rst b/Misc/NEWS.d/next/Core and Builtins/2020-09-15-23-29-49.bpo-41780.bOBUIH.rst
new file mode 100644 (file)
index 0000000..9a7594f
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2020-09-15-23-29-49.bpo-41780.bOBUIH.rst
@@ -0,0 +1,2 @@
+Fix :meth:`__dir__` of :class:`types.GenericAlias`. Patch by Batuhan
+Taskaya.

diff --git a/Objects/genericaliasobject.c b/Objects/genericaliasobject.c
index 87bd1ae5c1430b56ba6c0c5d04f3ac38b8785fe8..ab56e1c4bf1a860dba287147bce3c94d61a7fe95 100644 (file)
--- a/Objects/genericaliasobject.c
+++ b/Objects/genericaliasobject.c
@@ -487,11 +487,50 @@ ga_reduce(PyObject *self, PyObject *Py_UNUSED(ignored))
                          alias->origin, alias->args);
 }
 
+static PyObject *
+ga_dir(PyObject *self, PyObject *Py_UNUSED(ignored))
+{
+    gaobject *alias = (gaobject *)self;
+    PyObject *dir = PyObject_Dir(alias->origin);
+    if (dir == NULL) {
+        return NULL;
+    }
+
+    PyObject *dir_entry = NULL;
+    for (const char * const *p = attr_exceptions; ; p++) {
+        if (*p == NULL) {
+            break;
+        }
+        else {
+            dir_entry = PyUnicode_FromString(*p);
+            if (dir_entry == NULL) {
+                goto error;
+            }
+            int contains = PySequence_Contains(dir, dir_entry);
+            if (contains < 0) {
+                goto error;
+            }
+            if (contains == 0 && PyList_Append(dir, dir_entry) < 0) {
+                goto error;
+            }
+
+            Py_CLEAR(dir_entry);
+        }
+    }
+    return dir;
+
+error:
+    Py_DECREF(dir);
+    Py_XDECREF(dir_entry);
+    return NULL;
+}
+
 static PyMethodDef ga_methods[] = {
     {"__mro_entries__", ga_mro_entries, METH_O},
     {"__instancecheck__", ga_instancecheck, METH_O},
     {"__subclasscheck__", ga_subclasscheck, METH_O},
     {"__reduce__", ga_reduce, METH_NOARGS},
+    {"__dir__", ga_dir, METH_NOARGS},
     {0}
 };