overloads not recognised when self is typed as a Protocol #20091
Description
Bug Report
When subclassing a base class with overloads, and self is typed as a Protocol, only the first overload is recognised.
To Reproduce
from datetime import timedelta from typing import Generic, Protocol, TypeVar, overload, reveal_type T = TypeVar("T") T_CT = TypeVar("T_CT", contravariant=True) class Mixin(Generic[T]): @overload def d(self: Mixin[timedelta], other: float) -> Mixin[timedelta]: ... @overload def d(self: Mixin[timedelta], other: timedelta) -> Mixin[float]: ... reveal_type(Mixin[timedelta]().d(5.0)) # Mixin[timedelta], fine reveal_type(Mixin[timedelta]().d(timedelta(days=1))) # Mixin[float], fine class SupportsD(Protocol[T_CT, T]): def d(self, other: T_CT, /) -> Mixin[T]: ... class S(Mixin[T]): def div(self: SupportsD[T_CT, T], other: T_CT) -> S[T]: ... reveal_type(S[timedelta]().div(5.0)) # S[timedelta], fine reveal_type(S[timedelta]().div(timedelta(days=1))) # mypy arg-typeExpected Behavior
S[timedelta]().div(timedelta(days=1)) is revealed as S[float]
Actual Behavior
ttest.pyi:24: error: Argument 1 to "div" of "S" has incompatible type "timedelta"; expected "float" [arg-type] Your Environment
Mypy version used
1.18.2
Mypy command-line flags
none
Mypy configuration options from mypy.ini (and other config files):
[tool.mypy] # Import discovery namespace_packages = false explicit_package_bases = false ignore_missing_imports = true follow_imports = "normal" follow_imports_for_stubs = false no_site_packages = false no_silence_site_packages = false # Disallow dynamic typing disallow_any_unimported = false # TODO disallow_any_expr = false # TODO disallow_any_decorated = false # TODO disallow_any_explicit = false # TODO disallow_any_generics = false # TODO disallow_subclassing_any = false # TODO # Untyped definitions and calls disallow_untyped_calls = false # TODO disallow_untyped_defs = false # TODO disallow_incomplete_defs = false # TODO check_untyped_defs = true disallow_untyped_decorators = true # None and Optional handling no_implicit_optional = true strict_optional = true # Configuring warnings warn_redundant_casts = true warn_unused_ignores = true warn_no_return = true warn_return_any = false # TODO warn_unreachable = false # GH#27396 # Suppressing errors ignore_errors = false enable_error_code = "ignore-without-code" # same as in pandas # Miscellaneous strictness flags allow_untyped_globals = false allow_redefinition = false local_partial_types = false implicit_reexport = false # pyright behaves the same strict_equality = true # Configuring error messages show_error_context = false show_column_numbers = false show_error_codes = true Python version used:
3.12.10