Wiring import fixes numpy scipy (ets-labs#422)

* Add signature guards

* Fix flake8 errors and update changelog

* Fix slow numpy/scipy installs on pypy3

Author: rmk135

docs/main/changelog.rst

@@ -7,6 +7,12 @@ that were made in every particular version.
 From version 0.7.6 *Dependency Injector* framework strictly 
 follows `Semantic versioning`_
 
+Development version
+-------------------
+- Fix wiring to not crash on missing signatures.
+  See issue: `#420 <https://github.com/ets-labs/python-dependency-injector/issues/420>`_.
+  Thanks to `@Balthus1989 <https://github.com/Balthus1989>`_ for reporting the issue.
+
 4.29.1
 ------
 - Fix recursive copying issue in ``Delegate`` provider.

requirements-dev.txt

@@ -10,5 +10,7 @@ pyyaml
 httpx
 fastapi
 pydantic
+numpy
+scipy
 
 -r requirements-ext.txt

src/dependency_injector/wiring.py

@@ -298,6 +298,8 @@ def is_excluded(self, instance: object) -> bool:
             return True
         elif self._is_starlette_request_cls(instance):
             return True
+        elif self._is_builtin(instance):
+            return True
         else:
             return False
 
@@ -309,6 +311,9 @@ def _is_starlette_request_cls(self, instance: object) -> bool:
                and isinstance(instance, type) \
                and issubclass(instance, starlette.requests.Request)
 
+    def _is_builtin(self, instance: object) -> bool:
+        return inspect.isbuiltin(instance)
+
 
 def wire(  # noqa: C901
         container: Container,
@@ -476,7 +481,7 @@ def _unpatch_attribute(patched: PatchedAttribute) -> None:
     setattr(patched.member, patched.name, patched.marker)
 
 
-def _fetch_reference_injections(
+def _fetch_reference_injections(  # noqa: C901
         fn: Callable[..., Any],
 ) -> Tuple[Dict[str, Any], Dict[str, Any]]:
     # Hotfix, see:
@@ -488,7 +493,15 @@ def _fetch_reference_injections(
             )):
         fn = fn.__init__
 
-    signature = inspect.signature(fn)
+    try:
+        signature = inspect.signature(fn)
+    except ValueError as exception:
+        if 'no signature found' in str(exception):
+            return {}, {}
+        elif 'not supported by signature' in str(exception):
+            return {}, {}
+        else:
+            raise exception
 
     injections = {}
     closing = {}
@@ -874,9 +887,13 @@ def exec_module(self, module):
                 super().exec_module(module)
                 loader.wire_module(module)
 
+        class ExtensionFileLoader(importlib.machinery.ExtensionFileLoader):
+            ...
+
         loader_details = [
             (SourcelessFileLoader, importlib.machinery.BYTECODE_SUFFIXES),
             (SourceFileLoader, importlib.machinery.SOURCE_SUFFIXES),
+            (ExtensionFileLoader, importlib.machinery.EXTENSION_SUFFIXES),
         ]
 
         self._path_hook = importlib.machinery.FileFinder.path_hook(*loader_details)

tests/unit/samples/wiringsamples/module.py

@@ -1,6 +1,7 @@
 """Test module for wiring."""
 
 from decimal import Decimal
+import sys
 from typing import Callable
 
 from dependency_injector import providers
@@ -128,3 +129,16 @@ def test_class_decorator(service: Service = Provide[Container.service]):
 
 def test_container(container: Container = Provide[Container]):
     return container.service()
+
+
+# Import tests
+
+if 'pypy' not in sys.version.lower():
+    import numpy  # noqa
+    from numpy import *  # noqa
+
+    import scipy  # noqa
+    from scipy import *  # noqa
+
+    import builtins  # noqa
+    from builtins import *  # noqa

tox.ini

@@ -8,6 +8,8 @@ deps=
     typing_extensions
     httpx
     fastapi
+    numpy
+    scipy
 extras=
     yaml
     pydantic
@@ -62,6 +64,17 @@ extras=
 commands=
     python -m unittest discover -s tests/unit -p test_*_py2_py3.py
 
+[testenv:pypy3]
+deps=
+    httpx
+    fastapi
+extras=
+    yaml
+    flask
+commands=
+    python -m unittest discover -s tests/unit -p test_*_py2_py3.py
+
+
 [testenv:pylint]
 deps=
     pylint