Fixed #28241 -- Allowed module_has_submodule()'s module_name arg to be a dotted path.

1 files changed, 12 insertions, 0 deletions

diff --git a/tests/utils_tests/test_module_loading.py b/tests/utils_tests/test_module_loading.py
index 5362c2b06b..c114d84d88 100644
--- a/tests/utils_tests/test_module_loading.py
+++ b/tests/utils_tests/test_module_loading.py
@@ -48,6 +48,18 @@ class DefaultLoader(unittest.TestCase):
         with self.assertRaises(ImportError):
             import_module('utils_tests.test_no_submodule.anything')
 
+    def test_has_sumbodule_with_dotted_path(self):
+        """Nested module existence can be tested."""
+        test_module = import_module('utils_tests.test_module')
+        # A grandchild that exists.
+        self.assertIs(module_has_submodule(test_module, 'child_module.grandchild_module'), True)
+        # A grandchild that doesn't exist.
+        self.assertIs(module_has_submodule(test_module, 'child_module.no_such_module'), False)
+        # A grandchild whose parent doesn't exist.
+        self.assertIs(module_has_submodule(test_module, 'no_such_module.grandchild_module'), False)
+        # A grandchild whose parent is not a package.
+        self.assertIs(module_has_submodule(test_module, 'good_module.no_such_module'), False)
+
 
 class EggLoader(unittest.TestCase):
     def setUp(self):