typing

aio-libs · Oct 7, 2024 · 317aee9 · 317aee9
1 parent 1b06049
commit 317aee9
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Showing 3 changed files with 93 additions and 29 deletions.
diff --git a/src/propcache/_helpers_py.py b/src/propcache/_helpers_py.py
@@ -1,10 +1,28 @@
 """Various helper functions."""
 
+import sys
 from functools import cached_property
-from typing import Any, Callable, Dict, Generic, Optional, Protocol, Type, TypeVar
+from typing import (
+    Any,
+    Callable,
+    Dict,
+    Generic,
+    Optional,
+    Protocol,
+    Type,
+    TypeVar,
+    Union,
+    overload,
+)
 
 __all__ = ("under_cached_property", "cached_property")
 
+
+if sys.version_info >= (3, 11):
+    from typing import Self
+else:
+    Self = Any
+
 _T = TypeVar("_T")
 
 
@@ -27,7 +45,17 @@ def __init__(self, wrapped: Callable[..., _T]) -> None:
         self.__doc__ = wrapped.__doc__
         self.name = wrapped.__name__
 
-    def __get__(self, inst: _TSelf[_T], owner: Optional[Type[Any]] = None) -> _T:
+    @overload
+    def __get__(self, inst: None, owner: Optional[Type[Any]] = None) -> Self: ...
+
+    @overload
+    def __get__(self, inst: _TSelf[_T], owner: Optional[Type[Any]] = None) -> _T: ...
+
+    def __get__(
+        self, inst: Optional[_TSelf[_T]], owner: Optional[Type[Any]] = None
+    ) -> Union[_T, Self]:
+        if inst is None:
+            return self
         try:
             try:
                 return inst._cache[self.name]

diff --git a/tests/test_cached_property.py b/tests/test_cached_property.py
@@ -1,15 +1,22 @@
 from operator import not_
 from types import ModuleType
+from typing import Type
 
 import pytest
 
+from propcache.api import cached_property
+
+CPType = Type[cached_property]
+
 
 def test_cached_property(propcache_module: ModuleType) -> None:
+    cp: CPType = propcache_module.cached_property
+
     class A:
         def __init__(self) -> None:
             """Init."""
 
-        @propcache_module.cached_property
+        @cp
         def prop(self) -> int:
             return 1
 
@@ -18,12 +25,14 @@ def prop(self) -> int:
 
 
 def test_cached_property_class(propcache_module: ModuleType) -> None:
+    cp: CPType = propcache_module.cached_property
+
     class A:
         def __init__(self) -> None:
             """Init."""
             # self._cache not set because its never accessed in this test
 
-        @propcache_module.cached_property
+        @cp
         def prop(self) -> None:
             """Docstring."""
 
@@ -32,14 +41,16 @@ def prop(self) -> None:
 
 
 def test_cached_property_without_cache(propcache_module: ModuleType) -> None:
+    cp: CPType = propcache_module.cached_property
+
     class A:
 
         __slots__ = ()
 
         def __init__(self) -> None:
             pass
 
-        @propcache_module.cached_property
+        @cp
         def prop(self) -> None:
             """Mock property."""
 
@@ -50,14 +61,16 @@ def prop(self) -> None:
 
 
 def test_cached_property_check_without_cache(propcache_module: ModuleType) -> None:
+    cp: CPType = propcache_module.cached_property
+
     class A:
 
         __slots__ = ()
 
         def __init__(self) -> None:
             """Init."""
 
-        @propcache_module.cached_property
+        @cp
         def prop(self) -> None:
             """Mock property."""
 
@@ -67,40 +80,43 @@ def prop(self) -> None:
 
 
 def test_cached_property_caching(propcache_module: ModuleType) -> None:
+    cp: CPType = propcache_module.cached_property
 
     class A:
         def __init__(self) -> None:
             """Init."""
 
-        @propcache_module.cached_property
+        @cp
         def prop(self) -> int:
             """Docstring."""
             return 1
 
     a = A()
-    assert 1 == a.prop
+    assert a.prop == 1
 
 
 def test_cached_property_class_docstring(propcache_module: ModuleType) -> None:
+    cp: CPType = propcache_module.cached_property
 
     class A:
         def __init__(self) -> None:
             """Init."""
 
-        @propcache_module.cached_property
+        @cp
         def prop(self) -> None:
             """Docstring."""
 
-    assert isinstance(A.prop, propcache_module.cached_property)
+    assert isinstance(A.prop, cached_property)
     assert "Docstring." == A.prop.__doc__
 
 
 def test_set_name(propcache_module: ModuleType) -> None:
     """Test that the __set_name__ method is called and checked."""
+    cp: CPType = propcache_module.cached_property
 
     class A:
 
-        @propcache_module.cached_property
+        @cp
         def prop(self) -> None:
             """Docstring."""
 
@@ -113,12 +129,13 @@ def prop(self) -> None:
 
 def test_get_without_set_name(propcache_module: ModuleType) -> None:
     """Test that get without __set_name__ fails."""
-    cp = propcache_module.cached_property(not_)
+    cp: CPType = propcache_module.cached_property
+    cp_instance = cp(not_)
 
     class A:
         """A class."""
 
-    A.cp = cp  # type: ignore[attr-defined]
+    A.cp_instance = cp_instance  # type: ignore[attr-defined]
     match = r"Cannot use cached_property instance "
     with pytest.raises(TypeError, match=match):
         _ = A().cp  # type: ignore[attr-defined]
diff --git a/tests/test_under_cached_property.py b/tests/test_under_cached_property.py
@@ -1,15 +1,21 @@
 from types import ModuleType
-from typing import Any, Dict
+from typing import Any, Dict, Type
 
 import pytest
 
+from propcache.api import under_cached_property
+
+UCPType = Type[under_cached_property]
+
 
 def test_under_cached_property(propcache_module: ModuleType) -> None:
+    ucp: UCPType = propcache_module.under_cached_property
+
     class A:
         def __init__(self) -> None:
-            self._cache: Dict[str, Any] = {}
+            self._cache: Dict[str, int] = {}
 
-        @propcache_module.under_cached_property
+        @ucp
         def prop(self) -> int:
             return 1
 
@@ -18,25 +24,28 @@ def prop(self) -> int:
 
 
 def test_under_cached_property_class(propcache_module: ModuleType) -> None:
+    ucp: UCPType = propcache_module.under_cached_property
+
     class A:
         def __init__(self) -> None:
             """Init."""
-            # self._cache not set because its never accessed in this test
 
-        @propcache_module.under_cached_property
+        @ucp
         def prop(self) -> None:
             """Docstring."""
 
-    assert isinstance(A.prop, propcache_module.under_cached_property)
+    assert isinstance(A.prop, ucp)
     assert A.prop.__doc__ == "Docstring."
 
 
 def test_under_cached_property_assignment(propcache_module: ModuleType) -> None:
+    ucp: UCPType = propcache_module.under_cached_property
+
     class A:
         def __init__(self) -> None:
             self._cache: Dict[str, Any] = {}
 
-        @propcache_module.under_cached_property
+        @ucp
         def prop(self) -> None:
             """Mock property."""
 
@@ -47,11 +56,14 @@ def prop(self) -> None:
 
 
 def test_under_cached_property_without_cache(propcache_module: ModuleType) -> None:
+    ucp: UCPType = propcache_module.under_cached_property
+
     class A:
         def __init__(self) -> None:
             """Init."""
+            self._cache: Dict[str, int] = {}
 
-        @propcache_module.under_cached_property
+        @ucp
         def prop(self) -> None:
             """Mock property."""
 
@@ -64,42 +76,49 @@ def prop(self) -> None:
 def test_under_cached_property_check_without_cache(
     propcache_module: ModuleType,
 ) -> None:
+    ucp: UCPType = propcache_module.under_cached_property
+
     class A:
         def __init__(self) -> None:
             """Init."""
+            # Note that self._cache is intentionally missing
+            # here to verify AttributeError
 
-        @propcache_module.under_cached_property
+        @ucp
         def prop(self) -> None:
             """Mock property."""
 
     a = A()
     with pytest.raises(AttributeError):
-        assert a.prop == 1
+        _ = a.prop  # type: ignore[call-overload]
 
 
 def test_under_cached_property_caching(propcache_module: ModuleType) -> None:
+    ucp: UCPType = propcache_module.under_cached_property
 
     class A:
         def __init__(self) -> None:
-            self._cache: Dict[str, Any] = {}
+            self._cache: Dict[str, int] = {}
 
-        @propcache_module.under_cached_property
+        @ucp
         def prop(self) -> int:
             """Docstring."""
             return 1
 
     a = A()
-    assert 1 == a.prop
+    assert a.prop == 1
 
 
 def test_under_cached_property_class_docstring(propcache_module: ModuleType) -> None:
+    ucp: UCPType = propcache_module.under_cached_property
+
     class A:
         def __init__(self) -> None:
             """Init."""
 
-        @propcache_module.under_cached_property
-        def prop(self) -> None:
+        @ucp
+        def prop(self) -> Any:
             """Docstring."""
 
-    assert isinstance(A.prop, propcache_module.under_cached_property)
+    assert isinstance(A.prop, ucp)
     assert "Docstring." == A.prop.__doc__