Update mypy from <1.18 to <1.21 (support through 1.20.1) (#2373)

* Fix typesafety test expectations for mypy 1.18 changes

- Update 'Cannot infer type argument N' → 'Cannot infer value of type parameter X'
- Remove no longer emitted '"Never" not callable' error
- Remove no longer emitted 'erased type of self' errors

Agent-Logs-Url: https://github.com/dry-python/returns/sessions/f332ee3a-c556-47ec-a276-8119a6a98aca

Co-authored-by: sobolevn <4660275+sobolevn@users.noreply.github.com>

* Update mypy support to 1.20.1 and fix all typesafety test expectations

- Update mypy version constraint from >=1.12,<1.18 to >=1.12,<1.21
- Fix builtins.X → X display changes in all typesafety YAML tests (mypy 1.20)
- Fix TypeVar backtick suffix removal in revealed types (mypy 1.20)
- Fix 'Cannot infer type argument N' → 'Cannot infer value of type parameter X' (mypy 1.18)
- Remove no longer emitted 'Never not callable' and 'erased type of self' errors (mypy 1.18)
- Remove no longer emitted 'defined here' note (mypy 1.20)
- Remove unused type: ignore comment in test_pickle.py (mypy 1.20 improvement)

Agent-Logs-Url: https://github.com/dry-python/returns/sessions/f332ee3a-c556-47ec-a276-8119a6a98aca

Co-authored-by: sobolevn <4660275+sobolevn@users.noreply.github.com>

* Bump mypy minimum to 1.19, regenerate lock file, clean up dead version checks

- Bump mypy version constraint from >=1.12,<1.21 to >=1.19,<1.21
- Regenerate poetry.lock to fix CI (lock file was out of sync)
- Remove dead version-check code for mypy < 1.16 in plugin
  (analyze_member_access msg parameter handling no longer needed)
- Remove unused imports (importlib.metadata.version, typing.Any)

Agent-Logs-Url: https://github.com/dry-python/returns/sessions/ec3a5de7-f5a3-49a4-a973-9265d6a4555e

Co-authored-by: sobolevn <4660275+sobolevn@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: sobolevn <4660275+sobolevn@users.noreply.github.com>

Author: Copilot

poetry.lock

@@ -35,7 +35,7 @@ dependencies.python = "^3.10"
 dependencies.typing-extensions = ">=4.0,<5.0"
 dependencies.pytest = { version = ">=8,<10", optional = true }
 dependencies.hypothesis = { version = "^6.151", optional = true }
-dependencies.mypy = { version = ">=1.12,<1.18", optional = true }
+dependencies.mypy = { version = ">=1.19,<1.21", optional = true }
 extras.compatible-mypy = [ "mypy" ]
 extras.check-laws = [ "pytest", "hypothesis" ]
 group.dev.dependencies.anyio = "^4.3"

pyproject.toml

@@ -1,7 +1,5 @@
 from collections.abc import Sequence
 from enum import Enum, unique
-from importlib.metadata import version
-from typing import Any
 
 from mypy.checkmember import analyze_member_access
 from mypy.plugin import (
@@ -63,13 +61,6 @@ def attribute_access(ctx: AttributeContext) -> MypyType:
     else:
         return ctx.default_attr_type
 
-    mypy_version_tuple = tuple(
-        map(int, version('mypy').partition('+')[0].split('.'))
-    )
-
-    extra_kwargs: dict[str, Any] = {}
-    if mypy_version_tuple < (1, 16):
-        extra_kwargs['msg'] = ctx.api.msg
     return analyze_member_access(
         ctx.context.name,  # type: ignore
         accessed,
@@ -80,7 +71,6 @@ def attribute_access(ctx: AttributeContext) -> MypyType:
         original_type=instance,
         chk=ctx.api,  # type: ignore
         in_literal_context=ctx.api.expr_checker.is_literal_context(),  # type: ignore
-        **extra_kwargs,
     )
 
 

returns/contrib/mypy/_features/kind.py

@@ -1,7 +1,6 @@
 from collections.abc import Sequence
-from importlib.metadata import version
 from types import MappingProxyType
-from typing import Any, Final, Literal, overload
+from typing import Final, Literal, overload
 
 from mypy.checkmember import analyze_member_access
 from mypy.nodes import ARG_NAMED, ARG_OPT
@@ -119,15 +118,6 @@ def translate_to_function(
     """
     checker = ctx.api.expr_checker  # type: ignore
 
-    mypy_version = version('mypy')
-    mypy_version_tuple = tuple(
-        map(int, mypy_version.partition('+')[0].split('.'))
-    )
-
-    extra_kwargs: dict[str, Any] = {}
-    if mypy_version_tuple < (1, 16):
-        extra_kwargs['msg'] = checker.msg
-
     return get_proper_type(
         analyze_member_access(
             '__call__',
@@ -138,6 +128,5 @@ def translate_to_function(
             is_operator=True,
             original_type=function_def,
             chk=checker.chk,
-            **extra_kwargs,
         )
     )

returns/contrib/mypy/_typeops/analtype.py

@@ -14,7 +14,7 @@ def __init__(self, inner_value: Any) -> None:
     def __eq__(self, other: object) -> bool:
         return (
             type(other) is type(self)  # noqa: WPS516
-            and self.inner_value == other.inner_value  # type: ignore[attr-defined]
+            and self.inner_value == other.inner_value
         )
 
     def __hash__(self) -> int:

tests/test_primitives/test_container/test_base_container/test_pickle.py

@@ -11,15 +11,15 @@
   main: |
     from returns.context import RequiresContext
 
-    reveal_type(RequiresContext[int, str].ask())  # N: Revealed type is "returns.context.requires_context.RequiresContext[builtins.str, builtins.str]"
+    reveal_type(RequiresContext[int, str].ask())  # N: Revealed type is "returns.context.requires_context.RequiresContext[str, str]"
 
 
 - case: requires_context_from_value
   disable_cache: false
   main: |
     from returns.context import RequiresContext
 
-    reveal_type(RequiresContext.from_value(1))  # N: Revealed type is "returns.context.requires_context.RequiresContext[builtins.int, Any]"
+    reveal_type(RequiresContext.from_value(1))  # N: Revealed type is "returns.context.requires_context.RequiresContext[int, Any]"
 
 
 - case: requires_context_from_context
@@ -28,4 +28,4 @@
     from returns.context import RequiresContext
 
     x: RequiresContext[int, str]
-    reveal_type(RequiresContext.from_context(x))  # N: Revealed type is "returns.context.requires_context.RequiresContext[builtins.int, builtins.str]"
+    reveal_type(RequiresContext.from_context(x))  # N: Revealed type is "returns.context.requires_context.RequiresContext[int, str]"

typesafety/test_context/test_requires_context/test_context.yml

@@ -6,7 +6,7 @@
     first: RequiresContext[TypeError, int]  # we can only cast return type
     second: RequiresContext[Exception, int] = first
 
-    reveal_type(second)  # N: Revealed type is "returns.context.requires_context.RequiresContext[builtins.Exception, builtins.int]"
+    reveal_type(second)  # N: Revealed type is "returns.context.requires_context.RequiresContext[Exception, int]"
 
 
 - case: context_wrong_cast
@@ -46,7 +46,7 @@
     reveal_type(func().bind(second))
     reveal_type(func().bind(third))
   out: |
-    main:21: note: Revealed type is "returns.context.requires_context.RequiresContext[builtins.int, main.B]"
+    main:21: note: Revealed type is "returns.context.requires_context.RequiresContext[int, main.B]"
     main:21: error: Argument 1 to "bind" of "RequiresContext" has incompatible type "Callable[[int], RequiresContext[int, A]]"; expected "Callable[[int], KindN[RequiresContext[Any, Any], int, B, Any]]"  [arg-type]
-    main:22: note: Revealed type is "returns.context.requires_context.RequiresContext[builtins.int, main.B]"
+    main:22: note: Revealed type is "returns.context.requires_context.RequiresContext[int, main.B]"
     main:22: error: Argument 1 to "bind" of "RequiresContext" has incompatible type "Callable[[int], RequiresContext[int, C]]"; expected "Callable[[int], KindN[RequiresContext[Any, Any], int, B, Any]]"  [arg-type]

typesafety/test_context/test_requires_context/test_requires_context_cast.yml

@@ -5,7 +5,7 @@
 
     first: RequiresContext[str, int]
 
-    reveal_type(first(1))  # N: Revealed type is "builtins.str"
+    reveal_type(first(1))  # N: Revealed type is "str"
 
 
 - case: requires_context_getattr
@@ -24,7 +24,7 @@
 
     first: RequiresContext[str, int]
 
-    reveal_type(first.map(lambda char: float(char)))  # N: Revealed type is "returns.context.requires_context.RequiresContext[builtins.float, builtins.int]"
+    reveal_type(first.map(lambda char: float(char)))  # N: Revealed type is "returns.context.requires_context.RequiresContext[float, int]"
 
 
 - case: requires_context_apply_correct
@@ -36,7 +36,7 @@
     first: RequiresContext[str, int]
     second: RequiresContext[Callable[[str], float], int]
 
-    reveal_type(first.apply(second))  # N: Revealed type is "returns.context.requires_context.RequiresContext[builtins.float, builtins.int]"
+    reveal_type(first.apply(second))  # N: Revealed type is "returns.context.requires_context.RequiresContext[float, int]"
 
 
 - case: requires_context_bind_correct
@@ -49,7 +49,7 @@
     def function(arg: str) -> RequiresContext[float, int]:
         return RequiresContext.from_value(1.5)
 
-    reveal_type(first.bind(function))  # N: Revealed type is "returns.context.requires_context.RequiresContext[builtins.float, builtins.int]"
+    reveal_type(first.bind(function))  # N: Revealed type is "returns.context.requires_context.RequiresContext[float, int]"
 
 
 - case: requires_context_bind_context_correct
@@ -62,7 +62,7 @@
     def function(arg: str) -> RequiresContext[float, int]:
         return RequiresContext.from_value(1.5)
 
-    reveal_type(first.bind_context(function))  # N: Revealed type is "returns.context.requires_context.RequiresContext[builtins.float, builtins.int]"
+    reveal_type(first.bind_context(function))  # N: Revealed type is "returns.context.requires_context.RequiresContext[float, int]"
 
 
 - case: requires_context_modify_env
@@ -71,7 +71,7 @@
     from returns.context import RequiresContext
 
     first: RequiresContext[float, int]
-    reveal_type(first.modify_env(int)('1'))  # N: Revealed type is "builtins.float"
+    reveal_type(first.modify_env(int)('1'))  # N: Revealed type is "float"
 
 
 - case: requires_context_call_wrong

typesafety/test_context/test_requires_context/test_requires_context_type.yml

@@ -6,7 +6,7 @@
 
     x: RequiresContextIOResult[int, float, str]
 
-    reveal_type(RequiresContext.from_requires_context_ioresult(x))  # N: Revealed type is "returns.context.requires_context.RequiresContext[returns.io.IOResult[builtins.int, builtins.float], builtins.str]"
+    reveal_type(RequiresContext.from_requires_context_ioresult(x))  # N: Revealed type is "returns.context.requires_context.RequiresContext[returns.io.IOResult[int, float], str]"
 
 
 - case: requires_context_from_requires_context_result
@@ -17,7 +17,7 @@
 
     x: RequiresContextResult[int, float, str]
 
-    reveal_type(RequiresContext.from_requires_context_result(x))  # N: Revealed type is "returns.context.requires_context.RequiresContext[returns.result.Result[builtins.int, builtins.float], builtins.str]"
+    reveal_type(RequiresContext.from_requires_context_result(x))  # N: Revealed type is "returns.context.requires_context.RequiresContext[returns.result.Result[int, float], str]"
 
 
 - case: requires_context_from_requires_context_future_result
@@ -28,4 +28,4 @@
 
     x: RequiresContextFutureResult[int, float, str]
 
-    reveal_type(RequiresContext.from_requires_context_future_result(x))  # N: Revealed type is "returns.context.requires_context.RequiresContext[returns.future.FutureResult[builtins.int, builtins.float], builtins.str]"
+    reveal_type(RequiresContext.from_requires_context_future_result(x))  # N: Revealed type is "returns.context.requires_context.RequiresContext[returns.future.FutureResult[int, float], str]"

typesafety/test_context/test_requires_context/test_requires_context_typecast.yml

@@ -11,4 +11,4 @@
   main: |
     from returns.context import RequiresContextFutureResult
 
-    reveal_type(RequiresContextFutureResult[int, bool, str].ask())  # N: Revealed type is "returns.context.requires_context_future_result.RequiresContextFutureResult[builtins.str, builtins.bool, builtins.str]"
+    reveal_type(RequiresContextFutureResult[int, bool, str].ask())  # N: Revealed type is "returns.context.requires_context_future_result.RequiresContextFutureResult[str, bool, str]"