Fill in missing type annotations in the public API

CHANGELOG.md

@@ -7,6 +7,10 @@ See [0Ver](https://0ver.org/).
 
 ## 0.31.0 WIP
 
+### Features
+
+- Adds missing type annotations
+
 ### Bugfixes
 
 - Fix `{Success, Failure}.swap` returning `Any`

returns/contrib/hypothesis/laws.py

@@ -177,7 +177,7 @@ def check_all_laws(
             )
 
 
-def pure_functions_factory(thing) -> st.SearchStrategy:
+def pure_functions_factory(thing: Any) -> st.SearchStrategy:
     """Factory to create pure functions."""
     like = (
         (lambda: None)

returns/contrib/pytest/plugin.py

@@ -42,18 +42,18 @@ def __init__(self, errors_handled: _ErrorsHandled) -> None:
 
     @staticmethod  # noqa: WPS602
     def assert_equal(  # noqa: WPS602
-        first,
-        second,
+        first: object,
+        second: object,
         *,
-        deps=None,
+        deps: object | None = None,
         backend: str = 'asyncio',
     ) -> None:
         """Can compare two containers even with extra calling and awaiting."""
         from returns.primitives.asserts import assert_equal  # noqa: PLC0415
 
         assert_equal(first, second, deps=deps, backend=backend)
 
-    def is_error_handled(self, container) -> bool:
+    def is_error_handled(self, container: 'ResultLikeN[Any, Any, Any]') -> bool:
         """Ensures that container has its error handled in the end."""
         return id(container) in self._errors_handled
 
@@ -131,7 +131,7 @@ class _DesiredFunctionFound(BaseException):  # noqa: WPS418
     """Exception to raise when expected function is found."""
 
 
-def pytest_configure(config) -> None:
+def pytest_configure(config: pytest.Config) -> None:
     """
     Hook to be executed on import.
 

returns/methods/cond.py

@@ -1,4 +1,4 @@
-from typing import TypeVar, overload
+from typing import Final, TypeVar, overload
 
 from returns.context import NoDeps
 from returns.interfaces.failable import DiverseFailableN, SingleFailableN
@@ -79,6 +79,6 @@ def internal_cond(
     return container_type.empty
 
 
-cond = kinded(internal_cond)
+cond: Final = kinded(internal_cond)
 """Kinded version of :func:`~internal_cond`,
 use it to infer real return type."""

returns/primitives/asserts.py

@@ -1,8 +1,8 @@
 def assert_equal(
-    first,
-    second,
+    first: object,
+    second: object,
     *,
-    deps=None,
+    deps: object | None = None,
     backend: str = 'asyncio',
 ) -> None:
     """

returns/primitives/container.py

@@ -29,7 +29,7 @@ class BaseContainer(Immutable, ABC):
     __slots__ = ('_inner_value',)
     _inner_value: Any
 
-    def __init__(self, inner_value) -> None:
+    def __init__(self, inner_value: object) -> None:
         """
         Wraps the given value in the Container.
 

returns/primitives/exceptions.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, Self
 
 if TYPE_CHECKING:
     from returns.interfaces.unwrappable import Unwrappable  # noqa: WPS433
@@ -11,6 +11,8 @@ class UnwrapFailedError(Exception):
 
     __slots__ = ('halted_container',)
 
+    halted_container: Unwrappable
+
     def __init__(self, container: Unwrappable) -> None:
         """
         Saves halted container in the inner state.
@@ -21,7 +23,7 @@ def __init__(self, container: Unwrappable) -> None:
         super().__init__()
         self.halted_container = container
 
-    def __reduce__(self):  # noqa: WPS603
+    def __reduce__(self) -> tuple[type[Self], tuple[Unwrappable]]:  # noqa: WPS603
         """Custom reduce method for pickle protocol.
 
         This helps properly reconstruct the exception during unpickling.

returns/primitives/hkt.py

@@ -88,7 +88,7 @@ def impossible(generic: T, value: V) -> T[V]:
 
     if TYPE_CHECKING:  # noqa: WPS604 # pragma: no cover
 
-        def __getattr__(self, attrname: str):
+        def __getattr__(self, attrname: str) -> Any:
             """
             This function is required for ``get_attribute_hook`` in mypy plugin.
 
@@ -214,7 +214,7 @@ class Kinded(Protocol[_FunctionDefType_co]):  # type: ignore
     def __get__(
         self,
         instance: _UpdatedType,
-        type_,
+        type_: type[Any] | None,
     ) -> Callable[..., _UpdatedType]:
         """Used to decorate and properly analyze method calls."""
 

returns/primitives/laws.py

@@ -1,5 +1,5 @@
 from collections.abc import Callable, Sequence
-from typing import ClassVar, Final, Generic, TypeVar, final
+from typing import Any, ClassVar, Final, Generic, TypeVar, final
 
 from returns.primitives.types import Immutable
 
@@ -25,10 +25,10 @@ class Law(Immutable):
 
     __slots__ = ('definition',)
 
-    definition: Callable
+    definition: Callable[..., Any]
     """Function used to define this law."""
 
-    def __init__(self, function) -> None:
+    def __init__(self, function: Callable[..., Any]) -> None:
         """Saves function to the inner state."""
         object.__setattr__(self, 'definition', function)
 

returns/trampolines.py

@@ -1,6 +1,6 @@
 from collections.abc import Callable
 from functools import wraps
-from typing import Generic, TypeVar, final
+from typing import Any, Generic, TypeVar, final
 
 from typing_extensions import ParamSpec
 
@@ -18,6 +18,10 @@ class Trampoline(Generic[_ReturnType]):
 
     __slots__ = ('args', 'func', 'kwargs')
 
+    func: Callable[..., _ReturnType]
+    args: tuple[Any, ...]
+    kwargs: dict[str, Any]
+
     def __init__(  # noqa: WPS451
         self,
         func: Callable[_FuncParams, _ReturnType],

typesafety/test_contrib/test_pytest/test_returns_asserts.yml

@@ -0,0 +1,7 @@
+- case: is_error_handled_non_container
+  disable_cache: false
+  main: |
+    from returns.contrib.pytest import ReturnsAsserts
+
+    def test(returns: ReturnsAsserts) -> None:
+        returns.is_error_handled(1)  # E: Argument 1 to "is_error_handled" of "ReturnsAsserts" has incompatible type "int"; expected "ResultLikeN[Any, Any, Any]"  [arg-type]

typesafety/test_methods/test_cond.yml

@@ -83,3 +83,11 @@
   out: |
     main:16: note: Revealed type is "main.MyOwn[str, float]"
     main:16: error: Only concrete class can be given where "type[MyOwn[Any, Any]]" is expected  [type-abstract]
+
+
+- case: cond_final
+  disable_cache: false
+  main: |
+    from returns.methods import cond
+
+    cond = cond  # E: Cannot assign to final name "cond"  [misc]

typesafety/test_trampolines/test_trampoline.yml

@@ -45,3 +45,14 @@
         return Trampoline(_accumulate, [1], 2)
 
     reveal_type(_accumulate([1, 2]))  # N: Revealed type is "int"
+
+
+- case: trampoline_attributes
+  disable_cache: false
+  main: |
+    from returns.trampolines import Trampoline
+
+    def test(t: Trampoline[int]) -> None:
+        reveal_type(t.func)  # N: Revealed type is "def (*Any, **Any) -> int"
+        reveal_type(t.args)  # N: Revealed type is "tuple[Any, ...]"
+        reveal_type(t.kwargs)  # N: Revealed type is "dict[str, Any]"