Fixes bug with ABC instances, annotates tests

Author: sobolevn

.readthedocs.yml

@@ -1,7 +1,7 @@
 version: 2
 
 python:
-  version: 3.7
+  version: 3.8
   install:
     - requirements: docs/requirements.txt
 

classes/_registry.py

@@ -5,7 +5,7 @@
 
 
 def choose_registry(  # noqa: WPS211
-    # It has multiple argumnets, but I don't see an easy and performant way
+    # It has multiple arguments, but I don't see an easy and performant way
     # to refactor it: I don't want to create extra structures
     # and I don't want to create a class with methods.
     typ: type,
@@ -30,7 +30,7 @@ def choose_registry(  # noqa: WPS211
     if is_concrete:
         # This means that this type has `__instancecheck__` defined,
         # which allows dynamic checks of what `isinstance` of this type.
-        # That's why we also treat this type as a conrete.
+        # That's why we also treat this type as a concrete.
         return concretes
     return instances
 

classes/_typeclass.py

@@ -418,7 +418,7 @@ def __call__(
         And all typeclasses that match ``Callable[[int, int], int]`` signature
         will typecheck.
         """
-        # At first, we try all our conrete types,
+        # At first, we try all our concrete types,
         # we don't cache it, because we cannot.
         # We only have runtime type info: `type([1]) == type(['a'])`.
         # It might be slow!

classes/contrib/mypy/typeops/call_signatures.py

@@ -43,7 +43,7 @@ def __init__(
         ctx: MethodSigContext,
     ) -> None:
         """Context that we need."""
-        self._signature = signature
+        self._signature = signature.copy_modified()
         self._instance_type = instance_type
         self._associated_type = associated_type
         self._ctx = ctx

tests/conftest.py

@@ -1,13 +1,16 @@
 from contextlib import contextmanager
+from typing import Callable, ContextManager, Iterator
 
 import pytest
 
+from classes._typeclass import _TypeClass  # noqa: WPS450
+
 
 @pytest.fixture(scope='session')
-def clear_cache():
+def clear_cache() -> Callable[[_TypeClass], ContextManager]:
     """Fixture to clear typeclass'es cache before and after."""
     @contextmanager
-    def factory(typeclass):
+    def factory(typeclass: _TypeClass) -> Iterator[None]:
         typeclass._dispatch_cache.clear()  # noqa: WPS437
         yield
         typeclass._dispatch_cache.clear()  # noqa: WPS437

tests/test_suppots.py

@@ -9,7 +9,7 @@ class _ListOfStrMeta(type):
     def __instancecheck__(cls, other) -> bool:
         return (
             isinstance(other, list) and
-            len(other) and
+            bool(other) and
             all(isinstance(list_item, str) for list_item in other)
         )
 
@@ -48,7 +48,7 @@ def _my_len_list_str(instance: List[str]) -> int:
     (1, False),  # default impl
     (_MyList(), True),  # mro fallback
     (_ListOfStr(), True),  # mro fallback
-    (_ListOfStr([1, 2, 3]), True),  # mro fallback
+    (_ListOfStr(['a']), True),  # mro fallback
 ])
 def test_supports(data_type, expected: bool, clear_cache) -> None:
     """Ensures that ``.supports`` works correctly."""

tests/test_typeclass/test_cache.py

@@ -34,7 +34,7 @@ def _my_abc(instance: _MyABC) -> int:
     return instance.get_number()
 
 
-def test_cache_concrete(clear_cache):  # noqa: WPS218
+def test_cache_concrete(clear_cache) -> None:  # noqa: WPS218
     """Ensures that cache invalidation for ABC types work correctly."""
     with clear_cache(my_typeclass):
         assert not my_typeclass._dispatch_cache  # noqa: WPS437
@@ -50,7 +50,7 @@ def test_cache_concrete(clear_cache):  # noqa: WPS218
         assert not my_typeclass._dispatch_cache  # noqa: WPS437
 
 
-def test_cached_calls(clear_cache):
+def test_cached_calls(clear_cache) -> None:
     """Ensures that regular types trigger cache."""
     with clear_cache(my_typeclass):
         my_typeclass.instance(int)(_my_int)

tests/test_typeclass/test_call.py

@@ -9,7 +9,7 @@ class _ListOfStrMeta(type):
     def __instancecheck__(cls, other) -> bool:
         return (
             isinstance(other, list) and
-            len(other) and
+            bool(other) and
             all(isinstance(list_item, str) for list_item in other)
         )
 
@@ -47,7 +47,7 @@ def _my_len_object(instance: object) -> int:
 @pytest.mark.parametrize('check_supports', [True, False])
 @pytest.mark.parametrize('clear_supports_cache', [True, False])
 @pytest.mark.parametrize(('data_type', 'expected'), [
-    (['a', 'b'], 0),  # conrete type
+    (['a', 'b'], 0),  # concrete type
     ([], 1),  # direct list call
     ([1, 2, 3], 1),  # direct list call
     ('', 2),  # sized protocol

tests/test_typeclass/test_callback.py

@@ -20,7 +20,7 @@ def _callback(
     return callback(instance)
 
 
-def test_callback():
+def test_callback() -> None:
     """Tests that callback works."""
     assert _callback('a', example) == 1
     assert _callback('abcd', example) == 4

tests/test_typeclass/test_protocols.py

@@ -23,12 +23,12 @@ def __len__(self) -> int:
         return 2
 
 
-def test_sized_protocol():
+def test_sized_protocol() -> None:
     """Ensure that sized protocol works."""
     assert protocols(_CustomSized(), '1') == '21'
     assert protocols([1, 2, 3], '0') == '30'
 
 
-def test_type_takes_over():
+def test_type_takes_over() -> None:
     """Ensure that int protocol works."""
     assert protocols('a', 'b') == 'ab'

tests/test_typeclass/test_regular_types.py

@@ -18,7 +18,7 @@ def _example_int(instance: int) -> str:
     return 'a' * instance
 
 
-def test_regular_type():
+def test_regular_type() -> None:
     """Ensures that types correctly work."""
     assert example([1, 2, 3]) == '123'
     assert example(['a', 'b', 'c']) == 'abc'

tests/test_typeclass/test_repr.py

@@ -15,7 +15,7 @@ def my_typeclass(instance) -> str:
     """Docs."""
 
 
-def test_str():
+def test_str() -> None:
     """Ensures that ``str`` is correct."""
     assert str(my_typeclass) == '<typeclass "my_typeclass">'
     assert str(

typesafety/test_typeclass/test_generics/test_generics_regular.yml

@@ -272,3 +272,30 @@
         ...
   out: |
     main:10: error: Expected variadic tuple "Tuple[X`-1, ...]", got "Tuple[X`-1, X`-1]"
+
+
+- case: typeclass_regression259_mutated_signature
+  disable_cache: false
+  main: |
+    from abc import ABCMeta, abstractmethod
+    from classes import typeclass
+
+    @typeclass
+    def my_typeclass(instance) -> int:
+        ...
+
+    class _MyABC(object, metaclass=ABCMeta):
+        ...
+
+    class _MyConcrete(_MyABC):
+        ...
+
+    @my_typeclass.instance(_MyABC)
+    def _my_abc(instance: _MyABC) -> int:
+        ...
+
+    my_typeclass(_MyConcrete())
+
+    @my_typeclass.instance(int)
+    def _my_int(instance: int) -> int:
+        ...