Makes classes compatible with mypy 1.2

.github/workflows/test.yml

@@ -38,7 +38,8 @@ jobs:
     - name: Run tests
       run: |
         poetry run flake8 .
-        poetry run mypy classes ./tests/**/*.py
+        # TODO: Remove `no-warn-unused-ignores` flag once we drop support for Python 3.7 and 3.8
+        poetry run mypy --no-warn-unused-ignores classes ./tests/**/*.py
         poetry run codespell classes tests docs typesafety README.md CONTRIBUTING.md CHANGELOG.md
         poetry run pytest classes tests docs/pages README.md
         poetry run doc8 -q docs

CHANGELOG.md

@@ -2,6 +2,11 @@
 
 We follow Semantic Versions since the `0.1.0` release.
 
+## Version 0.5.0 WIP
+
+### Features
+
+- Now requires `mypy>=1.2`
 
 ## Version 0.4.1
 

classes/_typeclass.py

@@ -379,7 +379,7 @@ def __call__(
         ],
         *args,
         **kwargs,
-    ) -> _ReturnType:
+    ) -> _ReturnType:  # type: ignore[type-var]
         """
         We use this method to actually call a typeclass.
 

classes/contrib/mypy/typeops/call_signatures.py

@@ -6,10 +6,10 @@
 from mypy.typeops import get_type_vars, make_simplified_union
 from mypy.types import CallableType, Instance, ProperType
 from mypy.types import Type as MypyType
-from mypy.types import TypeVarType, union_items
+from mypy.types import TypeVarType
 from typing_extensions import Final, final
 
-from classes.contrib.mypy.typeops import type_loader
+from classes.contrib.mypy.typeops import type_loader, union
 
 _INCOMPATIBLE_TYPEVAR_MSG: Final = (
     'Argument 1 to {0} has incompatible type "{1}"; expected "{2}"'
@@ -61,7 +61,7 @@ def _infer_type_var(
         first_arg: TypeVarType,
         passed_type: MypyType,
     ) -> CallableType:
-        instance_types = union_items(self._instance_type)
+        instance_types = union.union_items(self._instance_type)
         if isinstance(self._associated_type, Instance):
             instance_types.append(_load_supports_type(
                 first_arg,

classes/contrib/mypy/typeops/mro.py

@@ -4,10 +4,10 @@
 from mypy.subtypes import is_equivalent
 from mypy.types import Instance
 from mypy.types import Type as MypyType
-from mypy.types import UnionType, union_items
+from mypy.types import UnionType
 from typing_extensions import final
 
-from classes.contrib.mypy.typeops import type_loader
+from classes.contrib.mypy.typeops import type_loader, union
 
 
 @final
@@ -78,7 +78,7 @@ def __init__(
         """
         self._associated_type = associated_type
         self._ctx = ctx
-        self._instance_types = union_items(instance_type)
+        self._instance_types = union.union_items(instance_type)
 
         # Why do we store added types in a mutable global state?
         # Because, these types are hard to replicate without the proper context.
@@ -181,7 +181,7 @@ def _remove_unified_type(
         base = instance_type.type.bases[index]
         union_types = [
             type_arg
-            for type_arg in union_items(base.args[0])
+            for type_arg in union.union_items(base.args[0])
             if type_arg not in supports_type.args
         ]
         instance_type.type.bases[index] = supports_type.copy_modified(

classes/contrib/mypy/typeops/type_loader.py

@@ -23,7 +23,7 @@ def load_supports_type(
         [arg_type],
     )
     assert supports_spec
-    supports_spec.type._promote = None  # noqa: WPS437
+    supports_spec.type._promote = []  # noqa: WPS437
     return supports_spec
 
 

classes/contrib/mypy/typeops/union.py

@@ -0,0 +1,13 @@
+from typing import List
+
+from mypy.types import ProperType
+from mypy.types import Type as MypyType
+from mypy.types import flatten_nested_unions, get_proper_type
+
+
+def union_items(typ: MypyType) -> List[ProperType]:
+    """Get and flat all union types."""
+    return [
+        get_proper_type(union_member)
+        for union_member in flatten_nested_unions([typ])
+    ]

classes/contrib/mypy/validation/validate_instance/validate_runtime.py

@@ -2,8 +2,7 @@
 
 from mypy.erasetype import erase_type
 from mypy.plugin import MethodContext
-from mypy.sametypes import is_same_type
-from mypy.subtypes import is_subtype
+from mypy.subtypes import is_same_type, is_subtype
 from mypy.types import Instance
 from mypy.types import Type as MypyType
 from mypy.types import TypedDictType

pyproject.toml

@@ -48,18 +48,18 @@ python = "^3.7"
 typing_extensions = ">=3.10,<5.0"
 
 [tool.poetry.dev-dependencies]
-mypy = "^0.942"
+mypy = "^1.2.0"
 
 wemake-python-styleguide = "^0.17"
 flake8-pytest-style = "^1.6"
-nitpick = "^0.32"
+nitpick = "^0.33.1"
 
 safety = "^2.3"
 
 pytest = "^7.2"
 pytest-cov = "^4.0"
 pytest-randomly = "^3.12"
-pytest-mypy-plugins = "^1.9"
+pytest-mypy-plugins = "^1.10.1"
 
 sphinx = "^5.2"
 sphinx-autodoc-typehints = "^1.20"

setup.cfg

@@ -91,6 +91,8 @@ exclude_lines =
 plugins =
   classes.contrib.mypy.classes_plugin
 
+disable_error_code = empty-body
+
 allow_redefinition = false
 check_untyped_defs = true
 disallow_any_explicit = true

tests/test_associated_type/test_variadic_generic.py

@@ -31,6 +31,6 @@ def test_subtype_is_variadic():
     class Example(AssociatedType[_FirstType]):
         """Correct type."""
 
-    assert Example[int]
-    assert Example[int, int]  # type: ignore
-    assert Example[int, int, str]  # type: ignore
+    assert Example[int]  # type: ignore[truthy-function]
+    assert Example[int, int]  # type: ignore[misc]
+    assert Example[int, int, str]  # type: ignore[misc]

tests/test_supports.py

@@ -14,7 +14,7 @@ def __instancecheck__(cls, other) -> bool:
         )
 
 
-class _ListOfStr(List[str], metaclass=_ListOfStrMeta):
+class _ListOfStr(List[str], metaclass=_ListOfStrMeta):  # type: ignore[misc]
     """We use this for testing concrete type calls."""
 
 

tests/test_typeclass/test_call.py

@@ -14,7 +14,7 @@ def __instancecheck__(cls, other) -> bool:
         )
 
 
-class _ListOfStr(List[str], metaclass=_ListOfStrMeta):
+class _ListOfStr(List[str], metaclass=_ListOfStrMeta):  # type: ignore[misc]
     """We use this for testing concrete type calls."""
 
 

tests/test_typeclass/test_typed_dict.py

@@ -22,7 +22,7 @@ def __instancecheck__(cls, arg: object) -> bool:
 
     _Meta = type('_Meta', (_UserDictMeta, type(TypedDict)), {})
 
-    class UserDict(_User, metaclass=_Meta):
+    class UserDict(_User, metaclass=_Meta):  # type: ignore[misc]
         """We use this class to represent a typed dict with instance check."""
 
     @typeclass

typesafety/test_associated_type/test_validation/test_base_classes.yml

@@ -10,7 +10,7 @@
     def to_json(instance, verbose: bool = False) -> str:
         ...
   out: |
-    main:6: error: Single direct subclass of "classes._typeclass.AssociatedType" required; got "main.ToJson"
+    main:6: error: Single direct subclass of "classes._typeclass.AssociatedType" required; got "main.ToJson"  [misc]
 
 
 - case: typeclass_definied_by_multiple_parents
@@ -28,4 +28,4 @@
     def to_json(instance, verbose: bool = False) -> str:
         ...
   out: |
-    main:9: error: Single direct subclass of "classes._typeclass.AssociatedType" required; got "main.ToJson"
+    main:9: error: Single direct subclass of "classes._typeclass.AssociatedType" required; got "main.ToJson"  [misc]

typesafety/test_associated_type/test_validation/test_bodies.yml

@@ -11,7 +11,7 @@
     def compare(instance) -> int:
         ...
   out: |
-    main:7: error: Associated types must not have bodies
+    main:7: error: Associated types must not have bodies  [misc]
 
 
 - case: associated_type_with_attr
@@ -26,7 +26,7 @@
     def compare(instance) -> int:
         ...
   out: |
-    main:6: error: Associated types must not have bodies
+    main:6: error: Associated types must not have bodies  [misc]
 
 
 - case: associated_type_with_pass

typesafety/test_associated_type/test_validation/test_generic_missmatch.yml

@@ -14,4 +14,4 @@
     def compare(instance: List[X]) -> X:
         ...
   out: |
-    main:10: error: Generic type "main.Compare" with "0" type arguments does not match generic instance declaration "builtins.list[X`-1]" with "1" type arguments
+    main:10: error: Generic type "main.Compare" with "0" type arguments does not match generic instance declaration "builtins.list[X`-1]" with "1" type arguments  [misc]

typesafety/test_associated_type/test_validation/test_reuse.yml

@@ -14,4 +14,4 @@
     def from_json(instance) -> str:
         ...
   out: |
-    main:10: error: AssociatedType "main.ToJson" must not be reused, originally associated with "main.from_json"
+    main:10: error: AssociatedType "main.ToJson" must not be reused, originally associated with "main.from_json"  [misc]

typesafety/test_associated_type/test_variadic.yml

@@ -21,5 +21,5 @@
     One[int, str]
     Two[int]
   out: |
-    main:18: error: Type application has too many types (1 expected)
-    main:19: error: Type application has too few types (2 expected)
+    main:18: error: Type application has too many types (1 expected)  [misc]
+    main:19: error: Type application has too few types (2 expected)  [misc]

typesafety/test_supports_type/test_generic.yml

@@ -20,8 +20,8 @@
 
     x: Supports[Some[int]] = [1, 2, 3]
     y = {1, 2, 3}
-    reveal_type(some(x))  # N: Revealed type is "builtins.int*"
-    reveal_type(some(y))  # N: Revealed type is "builtins.int*"
+    reveal_type(some(x))  # N: Revealed type is "builtins.int"
+    reveal_type(some(y))  # N: Revealed type is "builtins.int"
 
 
 - case: supports_generic_correct2
@@ -47,8 +47,8 @@
 
     x: Supports[Some[int, str]] = {1: 'a'}
 
-    reveal_type(some(x, 1, 'a'))  # N: Revealed type is "builtins.str*"
-    reveal_type(some({'a': 1}, 'a', 1))  # N: Revealed type is "builtins.int*"
+    reveal_type(some(x, 1, 'a'))  # N: Revealed type is "builtins.str"
+    reveal_type(some({'a': 1}, 'a', 1))  # N: Revealed type is "builtins.int"
 
 
 - case: supports_generic_wrong1
@@ -73,8 +73,8 @@
     x: Supports[Some[int]] = {1, 2, 3}
     some({1, 2, 3})
   out: |
-    main:17: error: Incompatible types in assignment (expression has type "Set[int]", variable has type "Supports[Some[int]]")
-    main:18: error: Argument 1 to "some" has incompatible type "Set[int]"; expected "Supports[Some[<nothing>]]"
+    main:17: error: Incompatible types in assignment (expression has type "Set[int]", variable has type "Supports[Some[int]]")  [assignment]
+    main:18: error: Argument 1 to "some" has incompatible type "Set[int]"; expected "Supports[Some[<nothing>]]"  [arg-type]
 
 
 - case: supports_generic_wrong2
@@ -105,11 +105,11 @@
     y: Supports[Some[int]] = {1, 2, 3}
     z: Supports[Some[int]] = 1
   out: |
-    main:17: error: Found different typeclass ".instance" calls, use only "main.some"
-    main:17: error: Instance "Union[builtins.list[X`-1], builtins.set[X`-1]]" does not match inferred type "builtins.set[_T`1]"
-    main:22: error: Incompatible types in assignment (expression has type "List[int]", variable has type "Supports[Some[int]]")
-    main:23: error: Incompatible types in assignment (expression has type "Set[int]", variable has type "Supports[Some[int]]")
-    main:24: error: Incompatible types in assignment (expression has type "int", variable has type "Supports[Some[int]]")
+    main:17: error: Found different typeclass ".instance" calls, use only "main.some"  [misc]
+    main:17: error: Instance "Union[builtins.list[X`-1], builtins.set[X`-1]]" does not match inferred type "builtins.set[_T`1]"  [misc]
+    main:22: error: Incompatible types in assignment (expression has type "List[int]", variable has type "Supports[Some[int]]")  [assignment]
+    main:23: error: Incompatible types in assignment (expression has type "Set[int]", variable has type "Supports[Some[int]]")  [assignment]
+    main:24: error: Incompatible types in assignment (expression has type "int", variable has type "Supports[Some[int]]")  [assignment]
 
 
 - case: supports_multiple_one_generic_one_regular
@@ -177,5 +177,5 @@
         ...
 
     a: Supports[Some[str], Other[int]]
-    reveal_type(some(a))  # N: Revealed type is "builtins.str*"
-    reveal_type(other(a))  # N: Revealed type is "builtins.int*"
+    reveal_type(some(a))  # N: Revealed type is "builtins.str"
+    reveal_type(other(a))  # N: Revealed type is "builtins.int"

typesafety/test_supports_type/test_regular.yml

@@ -23,7 +23,7 @@
 
     convert_to_json(1)
     convert_to_json('a')
-    convert_to_json(None)  # E: Argument 1 to "convert_to_json" has incompatible type "None"; expected "Supports[ToJson]"
+    convert_to_json(None)  # E: Argument 1 to "convert_to_json" has incompatible type "None"; expected "Supports[ToJson]"  [arg-type]
 
 
 - case: typeclass_supports_type_restriction
@@ -74,7 +74,7 @@
 
     convert_to_json(to_json, 1)
     convert_to_json(to_json, 'a')
-    convert_to_json(to_json, None)  # E: Argument 2 to "convert_to_json" has incompatible type "None"; expected "Supports[ToJson]"
+    convert_to_json(to_json, None)  # E: Argument 2 to "convert_to_json" has incompatible type "None"; expected "Supports[ToJson]"  [arg-type]
 
 
 - case: typeclass_supports_with_function
@@ -97,7 +97,7 @@
     def convert_to_json(instance: Supports[to_json]) -> str:
        ...
   out: |
-    main:15: error: Function "main.to_json" is not valid as a type
+    main:15: error: Function "main.to_json" is not valid as a type  [valid-type]
     main:15: note: Perhaps you need "Callable[...]" or a callback protocol?
 
 
@@ -119,7 +119,7 @@
     def convert_to_json(instance: Supports[Other]) -> str:
         return to_json(instance)
   out: |
-    main:14: error: Argument 1 to "to_json" has incompatible type "Supports[Other]"; expected "Supports[ToJson]"
+    main:14: error: Argument 1 to "to_json" has incompatible type "Supports[Other]"; expected "Supports[ToJson]"  [arg-type]
 
 
 - case: supports_annotation
@@ -139,20 +139,20 @@
         return str(instance)
 
     a: Supports[ToJson] = 1
-    b: Supports[ToJson] = 'a'  # E: Incompatible types in assignment (expression has type "str", variable has type "Supports[ToJson]")
+    b: Supports[ToJson] = 'a'  # E: Incompatible types in assignment (expression has type "str", variable has type "Supports[ToJson]")  [assignment]
 
 
 - case: supports_type_bound
   disable_cache: false
   main: |
     from classes import Supports, AssociatedType
 
-    a: Supports[int]  # E: Type argument "builtins.int" of "Supports" must be a subtype of "classes._typeclass.AssociatedType"
+    a: Supports[int]  # E: Type argument "builtins.int" of "Supports" must be a subtype of "classes._typeclass.AssociatedType"  [misc]
 
     class A(AssociatedType):
         ...
 
-    b: Supports[A, int]  # E: Type argument "builtins.int" of "Supports" must be a subtype of "classes._typeclass.AssociatedType"
+    b: Supports[A, int]  # E: Type argument "builtins.int" of "Supports" must be a subtype of "classes._typeclass.AssociatedType"  [misc]
 
 
 - case: supports_multiple_types
@@ -261,5 +261,5 @@
     a: Supports[ToJson] = 'a'
     b: Supports[FromJson] = 'a'  # error
   out: |
-    main:21: error: Instance callback is incompatible "def (instance: builtins.str, other: Any) -> builtins.str"; expected "def (instance: builtins.str) -> builtins.str"
-    main:26: error: Incompatible types in assignment (expression has type "str", variable has type "Supports[FromJson]")
+    main:21: error: Instance callback is incompatible "def (instance: builtins.str, other: Any) -> builtins.str"; expected "def (instance: builtins.str) -> builtins.str"  [misc]
+    main:26: error: Incompatible types in assignment (expression has type "str", variable has type "Supports[FromJson]")  [assignment]

typesafety/test_typeclass/test__call__.yml

@@ -63,7 +63,7 @@
     some(B())  # ok
     some(C())  # ok
   out: |
-    main:20: error: Argument 1 to "some" has incompatible type "A"; expected "B"
+    main:20: error: Argument 1 to "some" has incompatible type "A"; expected "B"  [arg-type]
 
 
 - case: typeclass_call_generic_instance_variance
@@ -98,7 +98,7 @@
     some(b)  # ok
     some(c)  # ok
   out: |
-    main:26: error: Argument 1 to "some" has incompatible type "A[int]"; expected "B[<nothing>]"
+    main:26: error: Argument 1 to "some" has incompatible type "A[int]"; expected "B[<nothing>]"  [arg-type]
 
 
 - case: typeclass_call_variance_union1
@@ -129,7 +129,7 @@
     some(B())  # ok
     some(C())  # ok
   out: |
-    main:22: error: Argument 1 to "some" has incompatible type "A"; expected "B"
+    main:22: error: Argument 1 to "some" has incompatible type "A"; expected "B"  [arg-type]
 
 
 - case: typeclass_call_variance_union2
@@ -238,4 +238,4 @@
     def some(instance) -> int:
         ...
 
-    some()  # E: Missing positional argument "instance" in call to "__call__" of "_TypeClass"
+    some()  # E: Missing positional argument "instance" in call to "__call__" of "_TypeClass"  [call-arg]