Copying providers with sys stream injections (#211)

* Add fix + tests

* Update changelog

docs/main/changelog.rst

@@ -7,6 +7,11 @@ that were made in every particular version.
 From version 0.7.6 *Dependency Injector* framework strictly 
 follows `Semantic versioning`_
 
+Development version
+-------------------
+- Fix issue with copying providers that have  system streams injections
+  (``sys.stdin``, ``sys.stdout`` and ``sys.stderr``).
+
 3.14.2
 ------
 - Set Cython ``language_level=2``.

src/dependency_injector/providers.pyx

@@ -2075,4 +2075,19 @@ cpdef str represent_provider(object provider, object provides):
 
 cpdef object deepcopy(object instance, dict memo=None):
     """Return full copy of provider or container with providers."""
+    if memo is None:
+        memo = dict()
+
+    __add_sys_streams(memo)
+
     return copy.deepcopy(instance, memo)
+
+def __add_sys_streams(memo):
+    """Add system streams to memo dictionary.
+
+    This helps to avoid copying of system streams while making a deepcopy of
+    objects graph.
+    """
+    memo[id(sys.stdin)] = sys.stdin
+    memo[id(sys.stdout)] = sys.stdout
+    memo[id(sys.stderr)] = sys.stderr

tests/unit/providers/test_callables_py2_py3.py

@@ -1,5 +1,7 @@
 """Dependency injector callable providers unit tests."""
 
+import sys
+
 import unittest2 as unittest
 
 from dependency_injector import (
@@ -167,6 +169,18 @@ class CallableTests(unittest.TestCase):
         self.assertIsNot(object_provider, object_provider_copy)
         self.assertIsInstance(object_provider_copy, providers.Object)
 
+    def test_deepcopy_with_sys_streams(self):
+        provider = providers.Callable(_example)
+        provider.add_args(sys.stdin)
+        provider.add_kwargs(a2=sys.stdout)
+
+        provider_copy = providers.deepcopy(provider)
+
+        self.assertIsNot(provider, provider_copy)
+        self.assertIsInstance(provider_copy, providers.Callable)
+        self.assertIs(provider.args[0], sys.stdin)
+        self.assertIs(provider.kwargs['a2'], sys.stdout)
+
     def test_repr(self):
         provider = providers.Callable(_example)
 

tests/unit/providers/test_factories_py2_py3.py

@@ -1,5 +1,7 @@
 """Dependency injector factory providers unit tests."""
 
+import sys
+
 import unittest2 as unittest
 
 from dependency_injector import (
@@ -321,6 +323,20 @@ class FactoryTests(unittest.TestCase):
         self.assertIsNot(object_provider, object_provider_copy)
         self.assertIsInstance(object_provider_copy, providers.Object)
 
+    def test_deepcopy_with_sys_streams(self):
+        provider = providers.Factory(Example)
+        provider.add_args(sys.stdin)
+        provider.add_kwargs(a2=sys.stdout)
+        provider.add_attributes(a3=sys.stderr)
+
+        provider_copy = providers.deepcopy(provider)
+
+        self.assertIsNot(provider, provider_copy)
+        self.assertIsInstance(provider_copy, providers.Factory)
+        self.assertIs(provider.args[0], sys.stdin)
+        self.assertIs(provider.kwargs['a2'], sys.stdout)
+        self.assertIs(provider.attributes['a3'], sys.stderr)
+
     def test_repr(self):
         provider = providers.Factory(Example)
 

tests/unit/providers/test_singletons_py2_py3.py

@@ -1,5 +1,7 @@
 """Dependency injector singleton providers unit tests."""
 
+import sys
+
 import unittest2 as unittest
 
 from dependency_injector import (
@@ -322,6 +324,20 @@ class _BaseSingletonTestCase(object):
         self.assertIsNot(object_provider, object_provider_copy)
         self.assertIsInstance(object_provider_copy, providers.Object)
 
+    def test_deepcopy_with_sys_streams(self):
+        provider = providers.Singleton(Example)
+        provider.add_args(sys.stdin)
+        provider.add_kwargs(a2=sys.stdout)
+        provider.add_attributes(a3=sys.stderr)
+
+        provider_copy = providers.deepcopy(provider)
+
+        self.assertIsNot(provider, provider_copy)
+        self.assertIsInstance(provider_copy, providers.Singleton)
+        self.assertIs(provider.args[0], sys.stdin)
+        self.assertIs(provider.kwargs['a2'], sys.stdout)
+        self.assertIs(provider.attributes['a3'], sys.stderr)
+
     def test_reset(self):
         provider = self.singleton_cls(object)