fix: fix functools.wrapped functions (#28)

* fix: fix functools.wrapped functions

* test: add test for type resolution as well

src/in_n_out/_store.py

@@ -5,7 +5,7 @@
 import warnings
 import weakref
 from functools import cached_property, wraps
-from inspect import CO_VARARGS, isgeneratorfunction
+from inspect import CO_VARARGS, isgeneratorfunction, unwrap
 from types import CodeType
 from typing import (
     TYPE_CHECKING,
@@ -719,7 +719,7 @@ def _inner(func: Callable[P, R]) -> Callable[P, R]:
                 return self.inject_processors(func) if processors else func
 
             # bail if there aren't any annotations at all
-            code: Optional[CodeType] = getattr(func, "__code__", None)
+            code: Optional[CodeType] = getattr(unwrap(func), "__code__", None)
             if (code and not code.co_argcount) and "return" not in getattr(
                 func, "__annotations__", {}
             ):

tests/test_injection.py

@@ -1,3 +1,4 @@
+import functools
 from contextlib import nullcontext
 from inspect import isgeneratorfunction
 from typing import ContextManager, Generator, Optional
@@ -237,3 +238,22 @@ def generator_func() -> Generator:
 
     with pytest.raises(TypeError, match="generator function"):
         inject(generator_func, processors=True)
+
+
+def test_wrapped_functions():
+    def func(foo: Foo):
+        return foo
+
+    @functools.wraps(func)
+    def wrapper(*args, **kwargs):
+        return func(*args, **kwargs)
+
+    @functools.wraps(wrapper)
+    def wrapper2(*args, **kwargs):
+        return wrapper(*args, **kwargs)
+
+    injected = inject(wrapper2)
+
+    foo = Foo()
+    with register(providers={Foo: lambda: foo}):
+        assert injected() == foo

tests/test_type_resolution.py

@@ -98,3 +98,20 @@ def func2(x: int, y: str, z: list):
     ppf = pf(z=["hi"])
 
     assert resolve_type_hints(ppf) == {"x": int, "y": str, "z": list}
+
+
+def test_wrapped_resolution() -> None:
+    from functools import wraps
+
+    def func(x: int, y: str, z: list):
+        ...
+
+    @wraps(func)
+    def wrapper(*args, **kwargs):
+        return func(*args, **kwargs)
+
+    @wraps(wrapper)
+    def wrapper2(*args, **kwargs):
+        return wrapper(*args, **kwargs)
+
+    assert resolve_type_hints(wrapper2) == {"x": int, "y": str, "z": list}