Merge branch 'release/4.10.3' into master

docs/main/changelog.rst

@@ -7,6 +7,13 @@ that were made in every particular version.
 From version 0.7.6 *Dependency Injector* framework strictly 
 follows `Semantic versioning`_
 
+4.10.3
+------
+- Fix a bug in the ``Configuration`` provider: strict mode didn't work when provider
+  is overridden by ``None``.
+  See issue: `#358#issuecomment-761607432 <https://github.com/ets-labs/python-dependency-injector/issues/358#issuecomment-761607432>`_.
+  Many thanks to `Stefano Frazzetto <https://github.com/StefanoFrazzetto>`_ for reporting the issue.
+
 4.10.2
 ------
 - Fix a bug in ``Resource`` that cause failure when async resource depends on

src/dependency_injector/__init__.py

@@ -1,6 +1,6 @@
 """Top-level package."""
 
-__version__ = '4.10.2'
+__version__ = '4.10.3'
 """Version number.
 
 :type: str

src/dependency_injector/providers.pyx

@@ -1471,12 +1471,14 @@ cdef class Configuration(Object):
         :return: Option value.
         :rtype: Any
         """
-        keys = selector.split('.')
         value = self.__call__()
 
         if value is None:
+            if self.__strict or required:
+                raise Error('Undefined configuration option "{0}.{1}"'.format(self.__name, selector))
             return None
 
+        keys = selector.split('.')
         while len(keys) > 0:
             key = keys.pop(0)
             value = value.get(key, self.UNDEFINED)
@@ -1500,9 +1502,9 @@ cdef class Configuration(Object):
         :return: Overriding context.
         :rtype: :py:class:`OverridingContext`
         """
-        keys = selector.split('.')
         original_value = current_value = deepcopy(self.__call__())
 
+        keys = selector.split('.')
         while len(keys) > 0:
             key = keys.pop(0)
             if len(keys) == 0:

tests/unit/providers/test_configuration_py2_py3.py

@@ -214,6 +214,12 @@ class ConfigTests(unittest.TestCase):
         with self.assertRaisesRegex(errors.Error, 'Undefined configuration option "config.a"'):
             self.config.a()
 
+    def test_value_of_undefined_option_with_root_none_in_strict_mode(self):
+        self.config = providers.Configuration(strict=True)
+        self.config.override(None)
+        with self.assertRaisesRegex(errors.Error, 'Undefined configuration option "config.a"'):
+            self.config.a()
+
     def test_value_of_defined_none_option_in_strict_mode(self):
         self.config = providers.Configuration(strict=True)
         self.config.from_dict({'a': None})