fix(spy): match inspect.signature for staticmethods (#51)

Author: mcous

decoy/spy.py

@@ -3,7 +3,7 @@
 Classes in this module are heavily inspired by the
 [unittest.mock library](https://docs.python.org/3/library/unittest.mock.html).
 """
-from inspect import isclass, iscoroutinefunction, isfunction, signature
+from inspect import getattr_static, isclass, iscoroutinefunction, isfunction, signature
 from functools import partial
 from typing import get_type_hints, Any, Callable, Dict, NamedTuple, Optional
 
@@ -105,15 +105,19 @@ def __getattr__(self, name: str) -> Any:
             except Exception:
                 child_hint = None
 
-            child_spec = getattr(self._spec, name, child_hint)
+            child_spec = getattr_static(self._spec, name, child_hint)
 
         if isinstance(child_spec, property):
             child_spec = _get_type_hints(child_spec.fget).get("return")
 
+        if isinstance(child_spec, staticmethod):
+            child_spec = child_spec.__func__
+
         elif isclass(self._spec) and isfunction(child_spec):
             # `iscoroutinefunction` does not work for `partial` on Python < 3.8
             # check before we wrap it
             child_is_async = iscoroutinefunction(child_spec)
+
             # consume the `self` argument of the method to ensure proper
             # signature reporting by wrapping it in a partial
             child_spec = partial(child_spec, None)  # type: ignore[arg-type]

mkdocs.yml

@@ -31,12 +31,14 @@ theme:
         - media: "(prefers-color-scheme: light)"
           scheme: default
           primary: black
+          accent: indigo
           toggle:
               icon: material/weather-sunny
               name: Switch to dark mode
         - media: "(prefers-color-scheme: dark)"
           scheme: slate
           primary: amber
+          accent: yellow
           toggle:
               icon: material/weather-night
               name: Switch to light mode

tests/test_spy.py

@@ -4,7 +4,7 @@
 from typing import Any
 
 from decoy.spy_calls import SpyCall
-from decoy.spy import create_spy, AsyncSpy, SpyConfig
+from decoy.spy import create_spy, AsyncSpy, Spy, SpyConfig
 
 from .common import (
     noop,
@@ -349,6 +349,27 @@ def test_spy_matches_signature() -> None:
     )
 
 
+def test_spy_matches_static_signature() -> None:
+    """It should pass `inspect.signature` checks on static methods."""
+
+    class _StaticClass:
+        @staticmethod
+        def foo(bar: int) -> float:
+            raise NotImplementedError()
+
+        @staticmethod
+        async def bar(baz: str) -> float:
+            raise NotImplementedError()
+
+    class_spy = create_spy(SpyConfig(spec=_StaticClass, handle_call=noop))
+    actual_instance = _StaticClass()
+
+    assert inspect.signature(class_spy.foo) == inspect.signature(actual_instance.foo)
+    assert inspect.signature(class_spy.bar) == inspect.signature(actual_instance.bar)
+    assert isinstance(class_spy.foo, Spy)
+    assert isinstance(class_spy.bar, AsyncSpy)
+
+
 def test_spy_repr() -> None:
     """It should have an informative repr."""
     class_spy = create_spy(SpyConfig(spec=SomeClass, handle_call=noop))