Fix isinstance narrowing for unions with supertype members (#2169) #2222

jackulau · 2026-01-25T11:05:37Z

Summary

When narrowing a union type with isinstance, if a union member is a proper supertype of the isinstance target, we should
not narrow that member to the isinstance target with fabricated type arguments.

Before:

def test(arg: Mapping[str, int] | Iterable[tuple[str, int]]) -> None:                                                       
    if isinstance(arg, Mapping):                                                                                            
        reveal_type(arg)  # Mapping[str, int] | Mapping[tuple[str, int], Unknown]  ❌

After:
def test(arg: Mapping[str, int] | Iterable[tuple[str, int]]) -> None:
if isinstance(arg, Mapping):
reveal_type(arg) # Mapping[str, int] ✅

Problem

The issue occurs when:

The isinstance target has type parameters (e.g., Mapping[K, V])
A union member is a supertype of the isinstance target (e.g., Iterable is a supertype of Mapping)
Type variable unification causes is_subset_eq(Mapping[K, V], Iterable[tuple[str, int]]) to succeed by binding K =
tuple[str, int]

This resulted in fabricating Mapping[tuple[str, int], Unknown] from Iterable[tuple[str, int]], which is incorrect.

Solution

Added a check in narrow_isinstance to detect when a union member is a proper supertype of the isinstance target (with type
parameters). In this case, return Never instead of allowing the fabricated type through unification.

let is_supertype_in_union = !tparams.is_empty()
&& left.is_union()
&& self.is_subset_eq(&right, l)
&& !self.is_subset_eq(l, &right);

The condition checks:

isinstance target has type parameters (!tparams.is_empty())
We're processing a union (left.is_union())
isinstance target is a subtype of union member (is_subset_eq(&right, l))
Union member is NOT a subtype of isinstance target (!is_subset_eq(l, &right))

Test Plan

Added test case test_isinstance_mapping_iterable_union covering the issue
Verified edge cases:
Multiple Mapping types in union
MutableMapping (subtype of Mapping)
Non-generic isinstance targets
Reverse case (isinstance with Iterable on Mapping)
Non-union case preserves existing behavior

…2169)

jackulau · 2026-01-26T07:17:59Z

wip

yangdanny97 · 2026-01-26T15:04:40Z

thanks, the mypy primer diff looks promising, lmk when you want a review on this

rchen152 · 2026-01-26T18:51:49Z

@jackulau FYI you can convert the PR to a draft to indicate that it's in-progress and back to non-draft when it's ready for review: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/changing-the-stage-of-a-pull-request.

Added additional edge case tests for: - Subclass in union (dict with Mapping check) - Collection/Mapping hierarchy - Unrelated classes (Sequence/Mapping) - Superclass as isinstance target

github-actions · 2026-01-27T17:33:18Z

Diff from mypy_primer, showing the effect of this PR on open source code:

scrapy (https://github.com/scrapy/scrapy)
- ERROR scrapy/http/headers.py:37:15-63: `ItemsView[tuple[AnyStr, Any], Unknown] | ItemsView[AnyStr, Any] | Iterable[tuple[AnyStr, Any]]` is not assignable to variable `seq` with type `Iterable[tuple[AnyStr, Any]] | Mapping[AnyStr, Any]` [bad-assignment]
- ERROR scrapy/http/headers.py:40:41-44: `int | str | AnyStr` is not assignable to upper bound `bytes | str` of type variable `AnyStr` [bad-specialization]
- ERROR scrapy/utils/datatypes.py:90:15-63: `ItemsView[tuple[AnyStr, Any], Unknown] | ItemsView[AnyStr, Any] | Iterable[tuple[AnyStr, Any]]` is not assignable to variable `seq` with type `Iterable[tuple[AnyStr, Any]] | Mapping[AnyStr, Any]` [bad-assignment]
- ERROR scrapy/utils/datatypes.py:91:30-33: `int | str | AnyStr` is not assignable to upper bound `bytes | str` of type variable `AnyStr` [bad-specialization]
- ::error file=scrapy/http/headers.py,line=37,col=15,endLine=37,endColumn=63,title=Pyrefly bad-assignment::`ItemsView[tuple[AnyStr, Any], Unknown] | ItemsView[AnyStr, Any] | Iterable[tuple[AnyStr, Any]]` is not assignable to variable `seq` with type `Iterable[tuple[AnyStr, Any]] | Mapping[AnyStr, Any]`
- ::error file=scrapy/http/headers.py,line=40,col=41,endLine=40,endColumn=44,title=Pyrefly bad-specialization::`int | str | AnyStr` is not assignable to upper bound `bytes | str` of type variable `AnyStr`
- ::error file=scrapy/utils/datatypes.py,line=90,col=15,endLine=90,endColumn=63,title=Pyrefly bad-assignment::`ItemsView[tuple[AnyStr, Any], Unknown] | ItemsView[AnyStr, Any] | Iterable[tuple[AnyStr, Any]]` is not assignable to variable `seq` with type `Iterable[tuple[AnyStr, Any]] | Mapping[AnyStr, Any]`
- ::error file=scrapy/utils/datatypes.py,line=91,col=30,endLine=91,endColumn=33,title=Pyrefly bad-specialization::`int | str | AnyStr` is not assignable to upper bound `bytes | str` of type variable `AnyStr`

urllib3 (https://github.com/urllib3/urllib3)
- ERROR src/urllib3/_collections.py:357:26-29: Argument `str | tuple[str, str]` is not assignable to parameter `key` with type `str` in function `HTTPHeaderDict.add` [bad-argument-type]
- ::error file=src/urllib3/_collections.py,line=357,col=26,endLine=357,endColumn=29,title=Pyrefly bad-argument-type::Argument `str | tuple[str, str]` is not assignable to parameter `key` with type `str` in function `HTTPHeaderDict.add`

hydra-zen (https://github.com/mit-ll-responsible-ai/hydra-zen)
- ERROR src/hydra_zen/structured_configs/_implementations.py:1205:30-1215:14: No matching overload found for function `BuildsFn.builds` called with arguments: (type[Zen], (...) -> Unknown, exclude=list[str], pre_call=Just[(Any) -> Any] | list[Just[(Any) -> Any]] | None, unpack_kwargs=bool, resolve_pre_call=bool, run_in_context=bool, instantiation_wrapper=((Unknown) -> Unknown) | None, populate_full_signature=Literal[True]) [no-matching-overload]
+ ERROR src/hydra_zen/structured_configs/_implementations.py:1205:30-1215:14: No matching overload found for function `BuildsFn.builds` called with arguments: (type, Never, exclude=list[@_], pre_call=list[Never] | None, unpack_kwargs=Never, resolve_pre_call=Never, run_in_context=Never, instantiation_wrapper=Never, populate_full_signature=Literal[True]) [no-matching-overload]
- ::error file=src/hydra_zen/structured_configs/_implementations.py,line=1205,col=30,endLine=1215,endColumn=14,title=Pyrefly no-matching-overload::No matching overload found for function `BuildsFn.builds` called with arguments: (type[Zen], (...) -> Unknown, exclude=list[str], pre_call=Just[(Any) -> Any] | list[Just[(Any) -> Any]] | None, unpack_kwargs=bool, resolve_pre_call=bool, run_in_context=bool, instantiation_wrapper=((Unknown) -> Unknown) | None, populate_full_signature=Literal[True])%0A  Possible overloads:%0A  (__hydra_target: type[BuildsWithSig[type[R], P]], *, zen_partial: Literal[False] | None = ..., populate_full_signature: Literal[True], zen_wrappers: ZenWrappers = ..., zen_meta: Mapping[str, SupportedPrimitive] | None = ..., hydra_recursive: bool | None = ..., hydra_convert: Literal['all', 'none', 'object', 'partial'] | None = ..., hydra_defaults: list[DataClass_ | Mapping[str, Sequence[str] | str | None] | str | type[DataClass_]] | None = ..., dataclass_name: str | None = ..., builds_bases: tuple[()] = ..., zen_dataclass: DataclassOptions | None = None, frozen: bool = ..., zen_convert: ZenConvert | None = ...) -> type[BuildsWithSig[type[R], P]]%0A  (__hydra_target: (ParamSpec(P)) -> R, *, zen_partial: Literal[False] | None = ..., populate_full_signature: Literal[True], zen_wrappers: ZenWrappers = ..., zen_meta: Mapping[str, SupportedPrimitive] | None = ..., hydra_recursive: bool | None = ..., hydra_convert: Literal['all', 'none', 'object', 'partial'] | None = ..., hydra_defaults: list[DataClass_ | Mapping[str, Sequence[str] | str | None] | str | type[DataClass_]] | None = ..., dataclass_name: str | None = ..., builds_bases: tuple[()] = ..., zen_dataclass: DataclassOptions | None = None, frozen: bool = ..., zen_convert: ZenConvert | None = ...) -> type[BuildsWithSig[type[R], P]]%0A  (__hydra_target: type[AnyBuilds], *pos_args: T, *, zen_partial: Literal[False] | None = ..., populate_full_signature: bool = ..., zen_wrappers: ZenWrappers = ..., zen_meta: Mapping[str, SupportedPrimitive] | None = ..., hydra_recursive: bool | None = ..., hydra_convert: Literal['all', 'none', 'object', 'partial'] | None = ..., hydra_defaults: list[DataClass_ | Mapping[str, Sequence[str] | str | None] | str | type[DataClass_]] | None = ..., dataclass_name: str | None = ..., builds_bases: tuple[type[DataClass_], ...] = ..., zen_dataclass: DataclassOptions | None = None, frozen: bool = ..., zen_convert: ZenConvert | None = ..., **kwargs_for_target: T) -> type[Builds[Importable]]%0A  (__hydra_target: Importable, *pos_args: T, *, zen_partial: Literal[False] | None = ..., populate_full_signature: bool = ..., zen_wrappers: ZenWrappers = ..., zen_meta: Mapping[str, SupportedPrimitive] | None = ..., hydra_recursive: bool | None = ..., hydra_convert: Literal['all', 'none', 'object', 'partial'] | None = ..., hydra_defaults: list[DataClass_ | Mapping[str, Sequence[str] | str | None] | str | type[DataClass_]] | None = ..., dataclass_name: str | None = ..., builds_bases: tuple[type[DataClass_], ...] = ..., zen_dataclass: DataclassOptions | None = None, frozen: bool = ..., zen_convert: ZenConvert | None = ..., **kwargs_for_target: T) -> type[Builds[Importable]] [closest match]%0A  (__hydra_target: type[AnyBuilds], *pos_args: T, *, zen_partial: Literal[True], populate_full_signature: bool = ..., zen_wrappers: ZenWrappers = ..., zen_meta: Mapping[str, SupportedPrimitive] | None = ..., hydra_recursive: bool | None = ..., hydra_convert: Literal['all', 'none', 'object', 'partial'] | None = ..., hydra_defaults: list[DataClass_ | Mapping[str, Sequence[str] | str | None] | str | type[DataClass_]] | None = ..., dataclass_name: str | None = ..., builds_bases: tuple[type[DataClass_], ...] = ..., zen_dataclass: DataclassOptions | None = None, frozen: bool = ..., zen_convert: ZenConvert | None = ..., **kwargs_for_target: T) -> type[PartialBuilds]%0A  (__hydra_target: Importable, *pos_args: T, *, zen_partial: Literal[True], populate_full_signature: bool = ..., zen_wrappers: ZenWrappers = ..., zen_meta: Mapping[str, SupportedPrimitive] | None = ..., hydra_recursive: bool | None = ..., hydra_convert: Literal['all', 'none', 'object', 'partial'] | None = ..., hydra_defaults: list[DataClass_ | Mapping[str, Sequence[str] | str | None] | str | type[DataClass_]] | None = ..., dataclass_name: str | None = ..., builds_bases: tuple[type[DataClass_], ...] = ..., zen_dataclass: DataclassOptions | None = None, frozen: bool = ..., zen_convert: ZenConvert | None = ..., **kwargs_for_target: T) -> type[PartialBuilds]%0A  (__hydra_target: type[AnyBuilds], *pos_args: T, *, zen_partial: bool | None = ..., populate_full_signature: Literal[False] = ..., zen_wrappers: ZenWrappers = ..., zen_meta: Mapping[str, SupportedPrimitive] | None = ..., hydra_recursive: bool | None = ..., hydra_convert: Literal['all', 'none', 'object', 'partial'] | None = ..., hydra_defaults: list[DataClass_ | Mapping[str, Sequence[str] | str | None] | str | type[DataClass_]] | None = ..., dataclass_name: str | None = ..., builds_bases: tuple[type[DataClass_], ...] = ..., zen_dataclass: DataclassOptions | None = None, frozen: bool = ..., zen_convert: ZenConvert | None = ..., **kwargs_for_target: T) -> type[PartialBuilds] | type[Builds[Importable]]%0A  (__hydra_target: Importable, *pos_args: T, *, zen_partial: bool | None = ..., populate_full_signature: Literal[False] = ..., zen_wrappers: ZenWrappers = ..., zen_meta: Mapping[str, SupportedPrimitive] | None = ..., hydra_recursive: bool | None = ..., hydra_convert: Literal['all', 'none', 'object', 'partial'] | None = ..., hydra_defaults: list[DataClass_ | Mapping[str, Sequence[str] | str | None] | str | type[DataClass_]] | None = ..., dataclass_name: str | None = ..., builds_bases: tuple[type[DataClass_], ...] = ..., zen_dataclass: DataclassOptions | None = None, frozen: bool = ..., zen_convert: ZenConvert | None = ..., **kwargs_for_target: T) -> type[PartialBuilds] | type[Builds[Importable]]%0A  (__hydra_target: ((ParamSpec(P)) -> R) | Importable | type[Builds[Importable]], *pos_args: T, *, zen_partial: bool | None, populate_full_signature: bool = ..., zen_wrappers: ZenWrappers = ..., zen_meta: Mapping[str, SupportedPrimitive] | None = ..., hydra_recursive: bool | None = ..., hydra_convert: Literal['all', 'none', 'object', 'partial'] | None = ..., hydra_defaults: list[DataClass_ | Mapping[str, Sequence[str] | str | None] | str | type[DataClass_]] | None = ..., dataclass_name: str | None = ..., builds_bases: tuple[type[DataClass_], ...] = ..., zen_dataclass: DataclassOptions | None = None, frozen: bool = ..., zen_convert: ZenConvert | None = ..., **kwargs_for_target: T) -> type[PartialBuilds] | type[Builds[Importable]] | type[BuildsWithSig[type[R], P]]
+ ::error file=src/hydra_zen/structured_configs/_implementations.py,line=1205,col=30,endLine=1215,endColumn=14,title=Pyrefly no-matching-overload::No matching overload found for function `BuildsFn.builds` called with arguments: (type, Never, exclude=list[@_], pre_call=list[Never] | None, unpack_kwargs=Never, resolve_pre_call=Never, run_in_context=Never, instantiation_wrapper=Never, populate_full_signature=Literal[True])%0A  Possible overloads:%0A  (__hydra_target: type[BuildsWithSig[type[R], P]], *, zen_partial: Literal[False] | None = ..., populate_full_signature: Literal[True], zen_wrappers: ZenWrappers = ..., zen_meta: Mapping[str, SupportedPrimitive] | None = ..., hydra_recursive: bool | None = ..., hydra_convert: Literal['all', 'none', 'object', 'partial'] | None = ..., hydra_defaults: list[DataClass_ | Mapping[str, Sequence[str] | str | None] | str | type[DataClass_]] | None = ..., dataclass_name: str | None = ..., builds_bases: tuple[()] = ..., zen_dataclass: DataclassOptions | None = None, frozen: bool = ..., zen_convert: ZenConvert | None = ...) -> type[BuildsWithSig[type[R], P]]%0A  (__hydra_target: (ParamSpec(P)) -> R, *, zen_partial: Literal[False] | None = ..., populate_full_signature: Literal[True], zen_wrappers: ZenWrappers = ..., zen_meta: Mapping[str, SupportedPrimitive] | None = ..., hydra_recursive: bool | None = ..., hydra_convert: Literal['all', 'none', 'object', 'partial'] | None = ..., hydra_defaults: list[DataClass_ | Mapping[str, Sequence[str] | str | None] | str | type[DataClass_]] | None = ..., dataclass_name: str | None = ..., builds_bases: tuple[()] = ..., zen_dataclass: DataclassOptions | None = None, frozen: bool = ..., zen_convert: ZenConvert | None = ...) -> type[BuildsWithSig[type[R], P]]%0A  (__hydra_target: type[AnyBuilds], *pos_args: T, *, zen_partial: Literal[False] | None = ..., populate_full_signature: bool = ..., zen_wrappers: ZenWrappers = ..., zen_meta: Mapping[str, SupportedPrimitive] | None = ..., hydra_recursive: bool | None = ..., hydra_convert: Literal['all', 'none', 'object', 'partial'] | None = ..., hydra_defaults: list[DataClass_ | Mapping[str, Sequence[str] | str | None] | str | type[DataClass_]] | None = ..., dataclass_name: str | None = ..., builds_bases: tuple[type[DataClass_], ...] = ..., zen_dataclass: DataclassOptions | None = None, frozen: bool = ..., zen_convert: ZenConvert | None = ..., **kwargs_for_target: T) -> type[Builds[Importable]] [closest match]%0A  (__hydra_target: Importable, *pos_args: T, *, zen_partial: Literal[False] | None = ..., populate_full_signature: bool = ..., zen_wrappers: ZenWrappers = ..., zen_meta: Mapping[str, SupportedPrimitive] | None = ..., hydra_recursive: bool | None = ..., hydra_convert: Literal['all', 'none', 'object', 'partial'] | None = ..., hydra_defaults: list[DataClass_ | Mapping[str, Sequence[str] | str | None] | str | type[DataClass_]] | None = ..., dataclass_name: str | None = ..., builds_bases: tuple[type[DataClass_], ...] = ..., zen_dataclass: DataclassOptions | None = None, frozen: bool = ..., zen_convert: ZenConvert | None = ..., **kwargs_for_target: T) -> type[Builds[Importable]]%0A  (__hydra_target: type[AnyBuilds], *pos_args: T, *, zen_partial: Literal[True], populate_full_signature: bool = ..., zen_wrappers: ZenWrappers = ..., zen_meta: Mapping[str, SupportedPrimitive] | None = ..., hydra_recursive: bool | None = ..., hydra_convert: Literal['all', 'none', 'object', 'partial'] | None = ..., hydra_defaults: list[DataClass_ | Mapping[str, Sequence[str] | str | None] | str | type[DataClass_]] | None = ..., dataclass_name: str | None = ..., builds_bases: tuple[type[DataClass_], ...] = ..., zen_dataclass: DataclassOptions | None = None, frozen: bool = ..., zen_convert: ZenConvert | None = ..., **kwargs_for_target: T) -> type[PartialBuilds]%0A  (__hydra_target: Importable, *pos_args: T, *, zen_partial: Literal[True], populate_full_signature: bool = ..., zen_wrappers: ZenWrappers = ..., zen_meta: Mapping[str, SupportedPrimitive] | None = ..., hydra_recursive: bool | None = ..., hydra_convert: Literal['all', 'none', 'object', 'partial'] | None = ..., hydra_defaults: list[DataClass_ | Mapping[str, Sequence[str] | str | None] | str | type[DataClass_]] | None = ..., dataclass_name: str | None = ..., builds_bases: tuple[type[DataClass_], ...] = ..., zen_dataclass: DataclassOptions | None = None, frozen: bool = ..., zen_convert: ZenConvert | None = ..., **kwargs_for_target: T) -> type[PartialBuilds]%0A  (__hydra_target: type[AnyBuilds], *pos_args: T, *, zen_partial: bool | None = ..., populate_full_signature: Literal[False] = ..., zen_wrappers: ZenWrappers = ..., zen_meta: Mapping[str, SupportedPrimitive] | None = ..., hydra_recursive: bool | None = ..., hydra_convert: Literal['all', 'none', 'object', 'partial'] | None = ..., hydra_defaults: list[DataClass_ | Mapping[str, Sequence[str] | str | None] | str | type[DataClass_]] | None = ..., dataclass_name: str | None = ..., builds_bases: tuple[type[DataClass_], ...] = ..., zen_dataclass: DataclassOptions | None = None, frozen: bool = ..., zen_convert: ZenConvert | None = ..., **kwargs_for_target: T) -> type[PartialBuilds] | type[Builds[Importable]]%0A  (__hydra_target: Importable, *pos_args: T, *, zen_partial: bool | None = ..., populate_full_signature: Literal[False] = ..., zen_wrappers: ZenWrappers = ..., zen_meta: Mapping[str, SupportedPrimitive] | None = ..., hydra_recursive: bool | None = ..., hydra_convert: Literal['all', 'none', 'object', 'partial'] | None = ..., hydra_defaults: list[DataClass_ | Mapping[str, Sequence[str] | str | None] | str | type[DataClass_]] | None = ..., dataclass_name: str | None = ..., builds_bases: tuple[type[DataClass_], ...] = ..., zen_dataclass: DataclassOptions | None = None, frozen: bool = ..., zen_convert: ZenConvert | None = ..., **kwargs_for_target: T) -> type[PartialBuilds] | type[Builds[Importable]]%0A  (__hydra_target: ((ParamSpec(P)) -> R) | Importable | type[Builds[Importable]], *pos_args: T, *, zen_partial: bool | None, populate_full_signature: bool = ..., zen_wrappers: ZenWrappers = ..., zen_meta: Mapping[str, SupportedPrimitive] | None = ..., hydra_recursive: bool | None = ..., hydra_convert: Literal['all', 'none', 'object', 'partial'] | None = ..., hydra_defaults: list[DataClass_ | Mapping[str, Sequence[str] | str | None] | str | type[DataClass_]] | None = ..., dataclass_name: str | None = ..., builds_bases: tuple[type[DataClass_], ...] = ..., zen_dataclass: DataclassOptions | None = None, frozen: bool = ..., zen_convert: ZenConvert | None = ..., **kwargs_for_target: T) -> type[PartialBuilds] | type[Builds[Importable]] | type[BuildsWithSig[type[R], P]]

django-stubs (https://github.com/typeddjango/django-stubs)
+ ERROR mypy_django_plugin/transformers/fields.py:78:38-55: Expected class object, got `Never` [invalid-argument]
+ ::error file=mypy_django_plugin/transformers/fields.py,line=78,col=38,endLine=78,endColumn=55,title=Pyrefly invalid-argument::Expected class object, got `Never`

bidict (https://github.com/jab/bidict)
- ERROR bidict/_base.py:500:15-28: Argument `BidictBase[tuple[KT, VT], Unknown]` is not assignable to parameter `self` with type `BidictBase[tuple[tuple[KT, VT], Unknown], Unknown]` in function `BidictBase.inverse` [bad-argument-type]
- ERROR bidict/_iter.py:26:9-31: yield from value must be iterable, got `ItemsView[tuple[KT, VT], Unknown] | ItemsView[KT, VT]` [invalid-yield]
- ::error file=bidict/_base.py,line=500,col=15,endLine=500,endColumn=28,title=Pyrefly bad-argument-type::Argument `BidictBase[tuple[KT, VT], Unknown]` is not assignable to parameter `self` with type `BidictBase[tuple[tuple[KT, VT], Unknown], Unknown]` in function `BidictBase.inverse`
- ::error file=bidict/_iter.py,line=26,col=9,endLine=26,endColumn=31,title=Pyrefly invalid-yield::yield from value must be iterable, got `ItemsView[tuple[KT, VT], Unknown] | ItemsView[KT, VT]`

schemathesis (https://github.com/schemathesis/schemathesis)
- ERROR src/schemathesis/openapi/checks.py:144:42-59: Argument `Mapping[str, Any] | Unset | bool | dict[str, Any]` is not assignable to parameter `schema` with type `bool | dict[str, Any] | list[JsonSchema]` in function `schemathesis.core.jsonschema.bundler.unbundle` [bad-argument-type]
+ ERROR src/schemathesis/openapi/checks.py:144:42-59: Argument `Mapping[str, Any] | Unset | bool | dict[str, Never]` is not assignable to parameter `schema` with type `bool | dict[str, Any] | list[JsonSchema]` in function `schemathesis.core.jsonschema.bundler.unbundle` [bad-argument-type]
- ::error file=src/schemathesis/openapi/checks.py,line=144,col=42,endLine=144,endColumn=59,title=Pyrefly bad-argument-type::Argument `Mapping[str, Any] | Unset | bool | dict[str, Any]` is not assignable to parameter `schema` with type `bool | dict[str, Any] | list[JsonSchema]` in function `schemathesis.core.jsonschema.bundler.unbundle`
+ ::error file=src/schemathesis/openapi/checks.py,line=144,col=42,endLine=144,endColumn=59,title=Pyrefly bad-argument-type::Argument `Mapping[str, Any] | Unset | bool | dict[str, Never]` is not assignable to parameter `schema` with type `bool | dict[str, Any] | list[JsonSchema]` in function `schemathesis.core.jsonschema.bundler.unbundle`

pwndbg (https://github.com/pwndbg/pwndbg)
- ERROR pwndbg/aglib/heap/ptmalloc.py:268:27-51: No matching overload found for function `int.__new__` called with arguments: (type[int], Value | Unknown | None) [no-matching-overload]
+ ERROR pwndbg/aglib/heap/ptmalloc.py:268:27-51: No matching overload found for function `int.__new__` called with arguments: (type[int], Value | None) [no-matching-overload]
+ ERROR pwndbg/aglib/heap/ptmalloc.py:512:39-88: `in` is not supported between `int` and `Generator[Never, None, None]` [unsupported-operation]
+ ERROR pwndbg/aglib/heap/ptmalloc.py:532:30-34: `None` is not assignable to attribute `arena` with type `Arena` [bad-assignment]
- ERROR pwndbg/aglib/heap/ptmalloc.py:515:45-71: Object of class `NoneType` has no attribute `sizeof` [missing-attribute]
- ERROR pwndbg/aglib/heap/ptmalloc.py:518:25-54: Object of class `NoneType` has no attribute `sizeof` [missing-attribute]
- ERROR pwndbg/aglib/heap/ptmalloc.py:525:18-43: Object of class `NoneType` has no attribute `non_contiguous` [missing-attribute]
- ERROR pwndbg/aglib/heap/ptmalloc.py:601:27-51: No matching overload found for function `int.__new__` called with arguments: (type[int], Value | Unknown | None) [no-matching-overload]
+ ERROR pwndbg/aglib/heap/ptmalloc.py:601:27-51: No matching overload found for function `int.__new__` called with arguments: (type[int], Value | None) [no-matching-overload]
- ERROR pwndbg/aglib/heap/ptmalloc.py:758:20-28: `not in` is not supported between `None` and `Page` [unsupported-operation]
- ERROR pwndbg/aglib/heap/ptmalloc.py:758:20-47: `not in` is not supported between `int` and `None` [not-iterable]
- ERROR pwndbg/aglib/heap/ptmalloc.py:758:20-47: `not in` is not supported between `None` and `None` [not-iterable]
- ERROR pwndbg/aglib/heap/ptmalloc.py:759:43-60: Object of class `NoneType` has no attribute `start` [missing-attribute]
- ERROR pwndbg/aglib/heap/ptmalloc.py:2000:40-81: Object of class `NoneType` has no attribute `next` [missing-attribute]
- ERROR pwndbg/commands/ptmalloc2.py:100:37-43: Argument `int | None` is not assignable to parameter `offset` with type `int` in function `pwndbg.chain.format` [bad-argument-type]
- ERROR pwndbg/commands/ptmalloc2.py:104:61-67: Argument `int | None` is not assignable to parameter `offset` with type `int` in function `pwndbg.chain.format` [bad-argument-type]
- ERROR pwndbg/commands/ptmalloc2.py:122:37-69: Argument `int | None` is not assignable to parameter `offset` with type `int` in function `pwndbg.chain.format` [bad-argument-type]
- ERROR pwndbg/commands/ptmalloc2.py:403:68-88: Object of class `NoneType` has no attribute `address` [missing-attribute]
- ERROR pwndbg/commands/ptmalloc2.py:404:11-47: Object of class `NoneType` has no attribute `value_to_human_readable` [missing-attribute]
- ERROR pwndbg/commands/ptmalloc2.py:507:40-55: Argument `int | None` is not assignable to parameter `size` with type `int` in function `pwndbg.aglib.heap.ptmalloc.Bins.contains_chunk` [bad-argument-type]
- ERROR pwndbg/commands/ptmalloc2.py:520:68-78: Argument `int | None` is not assignable to parameter `size` with type `int` in function `pwndbg.aglib.heap.ptmalloc.GlibcMemoryAllocator.chunk_flags` [bad-argument-type]
+ ERROR pwndbg/commands/ptmalloc2.py:1131:63-78: Argument `list[Unknown] | list[Never]` is not assignable to parameter `collections` with type `list[Bins | None]` in function `bin_labels_mapping` [bad-argument-type]
- ERROR pwndbg/commands/ptmalloc2.py:1444:41-77: `<` is not supported between `int` and `None` [unsupported-operation]
- ERROR pwndbg/commands/ptmalloc2.py:1449:31-61: Object of class `NoneType` has no attribute `address` [missing-attribute]
- ERROR pwndbg/commands/ptmalloc2.py:1464:26-45: `None` is not subscriptable [unsupported-operation]
- ERROR pwndbg/commands/ptmalloc2.py:1466:26-42: `None` is not subscriptable [unsupported-operation]
- ERROR pwndbg/commands/ptmalloc2.py:1479:8-56: `<=` is not supported between `int` and `None` [unsupported-operation]
- ERROR pwndbg/commands/ptmalloc2.py:1483:13-1484:18: Object of class `NoneType` has no attribute `bins` [missing-attribute]
- ERROR pwndbg/commands/ptmalloc2.py:1501:46-92: `>=` is not supported between `int` and `None` [unsupported-operation]
- ERROR pwndbg/commands/ptmalloc2.py:1558:32-46: Argument `int | None` is not assignable to parameter `addr` with type `int` in function `read_chunk` [bad-argument-type]
- ERROR pwndbg/commands/ptmalloc2.py:1562:13-44: `&` is not supported between `None` and `Literal[2]` [unsupported-operation]
- ERROR pwndbg/commands/ptmalloc2.py:1562:74-1564:10: `+` is not supported between `None` and `int` [unsupported-operation]
- ERROR pwndbg/commands/ptmalloc2.py:1568:34-94: `+` is not supported between `None` and `int` [unsupported-operation]
- ERROR pwndbg/commands/ptmalloc2.py:1590:46-81: `>=` is not supported between `int` and `None` [unsupported-operation]
- ERROR pwndbg/gdblib/ptmalloc2_tracking.py:359:45-57: Argument `int | None` is not assignable to parameter `size` with type `int` in function `pwndbg.aglib.heap.ptmalloc.Bins.contains_chunk` [bad-argument-type]
- ::error file=pwndbg/aglib/heap/ptmalloc.py,line=268,col=27,endLine=268,endColumn=51,title=Pyrefly no-matching-overload::No matching overload found for function `int.__new__` called with arguments: (type[int], Value | Unknown | None)%0A  Possible overloads:%0A  (cls: type[int], x: ConvertibleToInt = 0, /) -> int [closest match]%0A  (cls: type[int], x: bytearray | bytes | str, /, base: SupportsIndex) -> int
+ ::error file=pwndbg/aglib/heap/ptmalloc.py,line=268,col=27,endLine=268,endColumn=51,title=Pyrefly no-matching-overload::No matching overload found for function `int.__new__` called with arguments: (type[int], Value | None)%0A  Possible overloads:%0A  (cls: type[int], x: ConvertibleToInt = 0, /) -> int [closest match]%0A  (cls: type[int], x: bytearray | bytes | str, /, base: SupportsIndex) -> int
+ ::error file=pwndbg/aglib/heap/ptmalloc.py,line=512,col=39,endLine=512,endColumn=88,title=Pyrefly unsupported-operation::`in` is not supported between `int` and `Generator[Never, None, None]`%0A  `int` is not assignable to contained type `Never`
+ ::error file=pwndbg/aglib/heap/ptmalloc.py,line=532,col=30,endLine=532,endColumn=34,title=Pyrefly bad-assignment::`None` is not assignable to attribute `arena` with type `Arena`
- ::error file=pwndbg/aglib/heap/ptmalloc.py,line=515,col=45,endLine=515,endColumn=71,title=Pyrefly missing-attribute::Object of class `NoneType` has no attribute `sizeof`
- ::error file=pwndbg/aglib/heap/ptmalloc.py,line=518,col=25,endLine=518,endColumn=54,title=Pyrefly missing-attribute::Object of class `NoneType` has no attribute `sizeof`
- ::error file=pwndbg/aglib/heap/ptmalloc.py,line=525,col=18,endLine=525,endColumn=43,title=Pyrefly missing-attribute::Object of class `NoneType` has no attribute `non_contiguous`
- ::error file=pwndbg/aglib/heap/ptmalloc.py,line=601,col=27,endLine=601,endColumn=51,title=Pyrefly no-matching-overload::No matching overload found for function `int.__new__` called with arguments: (type[int], Value | Unknown | None)%0A  Possible overloads:%0A  (cls: type[int], x: ConvertibleToInt = 0, /) -> int [closest match]%0A  (cls: type[int], x: bytearray | bytes | str, /, base: SupportsIndex) -> int
+ ::error file=pwndbg/aglib/heap/ptmalloc.py,line=601,col=27,endLine=601,endColumn=51,title=Pyrefly no-matching-overload::No matching overload found for function `int.__new__` called with arguments: (type[int], Value | None)%0A  Possible overloads:%0A  (cls: type[int], x: ConvertibleToInt = 0, /) -> int [closest match]%0A  (cls: type[int], x: bytearray | bytes | str, /, base: SupportsIndex) -> int
- ::error file=pwndbg/aglib/heap/ptmalloc.py,line=758,col=20,endLine=758,endColumn=28,title=Pyrefly unsupported-operation::`not in` is not supported between `None` and `Page`%0A  Argument `None` is not assignable to parameter `addr` with type `int` in function `pwndbg.lib.memory.Page.__contains__`
- ::error file=pwndbg/aglib/heap/ptmalloc.py,line=758,col=20,endLine=758,endColumn=47,title=Pyrefly not-iterable::`not in` is not supported between `int` and `None`
- ::error file=pwndbg/aglib/heap/ptmalloc.py,line=758,col=20,endLine=758,endColumn=47,title=Pyrefly not-iterable::`not in` is not supported between `None` and `None`
- ::error file=pwndbg/aglib/heap/ptmalloc.py,line=759,col=43,endLine=759,endColumn=60,title=Pyrefly missing-attribute::Object of class `NoneType` has no attribute `start`
- ::error file=pwndbg/aglib/heap/ptmalloc.py,line=2000,col=40,endLine=2000,endColumn=81,title=Pyrefly missing-attribute::Object of class `NoneType` has no attribute `next`
- ::error file=pwndbg/commands/ptmalloc2.py,line=100,col=37,endLine=100,endColumn=43,title=Pyrefly bad-argument-type::Argument `int | None` is not assignable to parameter `offset` with type `int` in function `pwndbg.chain.format`
- ::error file=pwndbg/commands/ptmalloc2.py,line=104,col=61,endLine=104,endColumn=67,title=Pyrefly bad-argument-type::Argument `int | None` is not assignable to parameter `offset` with type `int` in function `pwndbg.chain.format`
- ::error file=pwndbg/commands/ptmalloc2.py,line=122,col=37,endLine=122,endColumn=69,title=Pyrefly bad-argument-type::Argument `int | None` is not assignable to parameter `offset` with type `int` in function `pwndbg.chain.format`
- ::error file=pwndbg/commands/ptmalloc2.py,line=403,col=68,endLine=403,endColumn=88,title=Pyrefly missing-attribute::Object of class `NoneType` has no attribute `address`
- ::error file=pwndbg/commands/ptmalloc2.py,line=404,col=11,endLine=404,endColumn=47,title=Pyrefly missing-attribute::Object of class `NoneType` has no attribute `value_to_human_readable`
- ::error file=pwndbg/commands/ptmalloc2.py,line=507,col=40,endLine=507,endColumn=55,title=Pyrefly bad-argument-type::Argument `int | None` is not assignable to parameter `size` with type `int` in function `pwndbg.aglib.heap.ptmalloc.Bins.contains_chunk`
- ::error file=pwndbg/commands/ptmalloc2.py,line=520,col=68,endLine=520,endColumn=78,title=Pyrefly bad-argument-type::Argument `int | None` is not assignable to parameter `size` with type `int` in function `pwndbg.aglib.heap.ptmalloc.GlibcMemoryAllocator.chunk_flags`
+ ::error file=pwndbg/commands/ptmalloc2.py,line=1131,col=63,endLine=1131,endColumn=78,title=Pyrefly bad-argument-type::Argument `list[Unknown] | list[Never]` is not assignable to parameter `collections` with type `list[Bins | None]` in function `bin_labels_mapping`
- ::error file=pwndbg/commands/ptmalloc2.py,line=1444,col=41,endLine=1444,endColumn=77,title=Pyrefly unsupported-operation::`<` is not supported between `int` and `None`%0A  Argument `None` is not assignable to parameter `value` with type `int` in function `int.__lt__`
- ::error file=pwndbg/commands/ptmalloc2.py,line=1449,col=31,endLine=1449,endColumn=61,title=Pyrefly missing-attribute::Object of class `NoneType` has no attribute `address`
- ::error file=pwndbg/commands/ptmalloc2.py,line=1464,col=26,endLine=1464,endColumn=45,title=Pyrefly unsupported-operation::`None` is not subscriptable
- ::error file=pwndbg/commands/ptmalloc2.py,line=1466,col=26,endLine=1466,endColumn=42,title=Pyrefly unsupported-operation::`None` is not subscriptable
- ::error file=pwndbg/commands/ptmalloc2.py,line=1479,col=8,endLine=1479,endColumn=56,title=Pyrefly unsupported-operation::`<=` is not supported between `int` and `None`%0A  Argument `None` is not assignable to parameter `value` with type `int` in function `int.__le__`
- ::error file=pwndbg/commands/ptmalloc2.py,line=1483,col=13,endLine=1484,endColumn=18,title=Pyrefly missing-attribute::Object of class `NoneType` has no attribute `bins`
- ::error file=pwndbg/commands/ptmalloc2.py,line=1501,col=46,endLine=1501,endColumn=92,title=Pyrefly unsupported-operation::`>=` is not supported between `int` and `None`%0A  Argument `None` is not assignable to parameter `value` with type `int` in function `int.__ge__`
- ::error file=pwndbg/commands/ptmalloc2.py,line=1558,col=32,endLine=1558,endColumn=46,title=Pyrefly bad-argument-type::Argument `int | None` is not assignable to parameter `addr` with type `int` in function `read_chunk`
- ::error file=pwndbg/commands/ptmalloc2.py,line=1562,col=13,endLine=1562,endColumn=44,title=Pyrefly unsupported-operation::`&` is not supported between `None` and `Literal[2]`%0A  Argument `None` is not assignable to parameter `value` with type `int` in function `int.__rand__`
- ::error file=pwndbg/commands/ptmalloc2.py,line=1562,col=74,endLine=1564,endColumn=10,title=Pyrefly unsupported-operation::`+` is not supported between `None` and `int`%0A  Argument `None` is not assignable to parameter `value` with type `int` in function `int.__radd__`
- ::error file=pwndbg/commands/ptmalloc2.py,line=1568,col=34,endLine=1568,endColumn=94,title=Pyrefly unsupported-operation::`+` is not supported between `None` and `int`%0A  Argument `None` is not assignable to parameter `value` with type `int` in function `int.__radd__`
- ::error file=pwndbg/commands/ptmalloc2.py,line=1590,col=46,endLine=1590,endColumn=81,title=Pyrefly unsupported-operation::`>=` is not supported between `int` and `None`%0A  Argument `None` is not assignable to parameter `value` with type `int` in function `int.__ge__`
- ::error file=pwndbg/gdblib/ptmalloc2_tracking.py,line=359,col=45,endLine=359,endColumn=57,title=Pyrefly bad-argument-type::Argument `int | None` is not assignable to parameter `size` with type `int` in function `pwndbg.aglib.heap.ptmalloc.Bins.contains_chunk`

streamlit (https://github.com/streamlit/streamlit)
-  WARN lib/streamlit/dataframe_util.py:952:20-52: Redundant cast: `list[V_co]` is the same type as `list[V_co]` [redundant-cast]
- ::warning file=lib/streamlit/dataframe_util.py,line=952,col=20,endLine=952,endColumn=52,title=Pyrefly redundant-cast::Redundant cast: `list[V_co]` is the same type as `list[V_co]`

ibis (https://github.com/ibis-project/ibis)
- ERROR ibis/util.py:108:16-21: Returned type `list[dict[V, Unknown]]` is not assignable to declared return type `list[V]` [bad-return]
- ::error file=ibis/util.py,line=108,col=16,endLine=108,endColumn=21,title=Pyrefly bad-return::Returned type `list[dict[V, Unknown]]` is not assignable to declared return type `list[V]`

schema_salad (https://github.com/common-workflow-language/schema_salad)
- ERROR schema_salad/jsonld_context.py:234:33-38: No matching overload found for function `urllib.parse.urldefrag` called with arguments: (Iterable[str] | str | Unknown) [no-matching-overload]
+ ERROR schema_salad/jsonld_context.py:234:33-38: No matching overload found for function `urllib.parse.urldefrag` called with arguments: (Iterable[str] | str | Any) [no-matching-overload]
- ::error file=schema_salad/jsonld_context.py,line=234,col=33,endLine=234,endColumn=38,title=Pyrefly no-matching-overload::No matching overload found for function `urllib.parse.urldefrag` called with arguments: (Iterable[str] | str | Unknown)%0A  Possible overloads:%0A  (url: str) -> DefragResult [closest match]%0A  (url: bytearray | bytes | None) -> DefragResultBytes
+ ::error file=schema_salad/jsonld_context.py,line=234,col=33,endLine=234,endColumn=38,title=Pyrefly no-matching-overload::No matching overload found for function `urllib.parse.urldefrag` called with arguments: (Iterable[str] | str | Any)%0A  Possible overloads:%0A  (url: str) -> DefragResult [closest match]%0A  (url: bytearray | bytes | None) -> DefragResultBytes

aiohttp (https://github.com/aio-libs/aiohttp)
- ERROR aiohttp/cookiejar.py:230:23-38: `ItemsView[str, BaseCookie[str] | Morsel[Any] | str] | ItemsView[tuple[str, BaseCookie[str] | Morsel[Any] | str], Unknown] | dict_items[str, Morsel[str]]` is not assignable to variable `cookies` with type `BaseCookie[str] | Iterable[tuple[str, BaseCookie[str] | Morsel[Any] | str]] | Mapping[str, BaseCookie[str] | Morsel[Any] | str]` [bad-assignment]
- ::error file=aiohttp/cookiejar.py,line=230,col=23,endLine=230,endColumn=38,title=Pyrefly bad-assignment::`ItemsView[str, BaseCookie[str] | Morsel[Any] | str] | ItemsView[tuple[str, BaseCookie[str] | Morsel[Any] | str], Unknown] | dict_items[str, Morsel[str]]` is not assignable to variable `cookies` with type `BaseCookie[str] | Iterable[tuple[str, BaseCookie[str] | Morsel[Any] | str]] | Mapping[str, BaseCookie[str] | Morsel[Any] | str]`

nox (https://github.com/wntrblm/nox)
- ERROR nox/manifest.py:318:44-56: Argument `object | str` is not assignable to parameter `*args` with type `str` in function `_unique_list` [bad-argument-type]
+ ERROR nox/manifest.py:318:44-56: Argument `object` is not assignable to parameter `*args` with type `str` in function `_unique_list` [bad-argument-type]
- ERROR nox/manifest.py:337:38-44: `object | str` is not assignable to attribute `python` with type `Sequence[str] | bool | str | None` [bad-assignment]
+ ERROR nox/manifest.py:337:38-44: `object` is not assignable to attribute `python` with type `Sequence[str] | bool | str | None` [bad-assignment]
- ::error file=nox/manifest.py,line=318,col=44,endLine=318,endColumn=56,title=Pyrefly bad-argument-type::Argument `object | str` is not assignable to parameter `*args` with type `str` in function `_unique_list`
+ ::error file=nox/manifest.py,line=318,col=44,endLine=318,endColumn=56,title=Pyrefly bad-argument-type::Argument `object` is not assignable to parameter `*args` with type `str` in function `_unique_list`
- ::error file=nox/manifest.py,line=337,col=38,endLine=337,endColumn=44,title=Pyrefly bad-assignment::`object | str` is not assignable to attribute `python` with type `Sequence[str] | bool | str | None`
+ ::error file=nox/manifest.py,line=337,col=38,endLine=337,endColumn=44,title=Pyrefly bad-assignment::`object` is not assignable to attribute `python` with type `Sequence[str] | bool | str | None`

vision (https://github.com/pytorch/vision)
- ERROR torchvision/transforms/transforms.py:2154:40-50: Argument `Sequence[Unknown] | list[float | object | Unknown] | list[float]` is not assignable to parameter `alpha` with type `list[float]` in function `ElasticTransform.get_params` [bad-argument-type]
+ ERROR torchvision/transforms/transforms.py:2154:40-50: Argument `Sequence[Unknown] | list[float | object] | list[float]` is not assignable to parameter `alpha` with type `list[float]` in function `ElasticTransform.get_params` [bad-argument-type]
- ERROR torchvision/transforms/transforms.py:2154:52-62: Argument `Sequence[Unknown] | list[float | object | Unknown] | list[float]` is not assignable to parameter `sigma` with type `list[float]` in function `ElasticTransform.get_params` [bad-argument-type]
+ ERROR torchvision/transforms/transforms.py:2154:52-62: Argument `Sequence[Unknown] | list[float | object] | list[float]` is not assignable to parameter `sigma` with type `list[float]` in function `ElasticTransform.get_params` [bad-argument-type]
- ::error file=torchvision/transforms/transforms.py,line=2154,col=40,endLine=2154,endColumn=50,title=Pyrefly bad-argument-type::Argument `Sequence[Unknown] | list[float | object | Unknown] | list[float]` is not assignable to parameter `alpha` with type `list[float]` in function `ElasticTransform.get_params`
+ ::error file=torchvision/transforms/transforms.py,line=2154,col=40,endLine=2154,endColumn=50,title=Pyrefly bad-argument-type::Argument `Sequence[Unknown] | list[float | object] | list[float]` is not assignable to parameter `alpha` with type `list[float]` in function `ElasticTransform.get_params`
- ::error file=torchvision/transforms/transforms.py,line=2154,col=52,endLine=2154,endColumn=62,title=Pyrefly bad-argument-type::Argument `Sequence[Unknown] | list[float | object | Unknown] | list[float]` is not assignable to parameter `sigma` with type `list[float]` in function `ElasticTransform.get_params`
+ ::error file=torchvision/transforms/transforms.py,line=2154,col=52,endLine=2154,endColumn=62,title=Pyrefly bad-argument-type::Argument `Sequence[Unknown] | list[float | object] | list[float]` is not assignable to parameter `sigma` with type `list[float]` in function `ElasticTransform.get_params`

cwltool (https://github.com/common-workflow-language/cwltool)
- ERROR cwltool/process.py:318:51-58: Argument `MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None` is not assignable to parameter `obj` with type `MutableMapping[str, MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None] | MutableSequence[MutableMapping[str, MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None]] | None` in function `_collectDirEntries` [bad-argument-type]
- ERROR tests/test_examples.py:327:12-28: Cannot index into `bool` [bad-index]
- ERROR tests/test_examples.py:327:12-28: Cannot index into `float` [bad-index]
- ERROR tests/test_examples.py:327:12-28: Cannot index into `int` [bad-index]
- ERROR tests/test_examples.py:327:12-28: `None` is not subscriptable [unsupported-operation]
- ERROR tests/test_examples.py:327:12-40: Cannot index into `str` [bad-index]
- ERROR tests/test_examples.py:327:26-27: Cannot index into `MutableMapping[str, Unknown]` [bad-index]
- ERROR tests/test_examples.py:328:12-28: Cannot index into `bool` [bad-index]
- ERROR tests/test_examples.py:328:12-28: Cannot index into `float` [bad-index]
- ERROR tests/test_examples.py:328:12-28: Cannot index into `int` [bad-index]
- ERROR tests/test_examples.py:328:12-28: `None` is not subscriptable [unsupported-operation]
- ERROR tests/test_examples.py:328:26-27: Cannot index into `MutableMapping[str, Unknown]` [bad-index]
- ERROR tests/test_examples.py:329:12-28: Cannot index into `bool` [bad-index]
- ERROR tests/test_examples.py:329:12-28: Cannot index into `float` [bad-index]
- ERROR tests/test_examples.py:329:12-28: Cannot index into `int` [bad-index]
- ERROR tests/test_examples.py:329:12-28: `None` is not subscriptable [unsupported-operation]
- ERROR tests/test_examples.py:329:26-27: Cannot index into `MutableMapping[str, Unknown]` [bad-index]
- ERROR tests/test_examples.py:342:12-38: Cannot index into `MutableSequence[Unknown]` [bad-index]
- ERROR tests/test_examples.py:342:12-38: Cannot index into `bool` [bad-index]
- ERROR tests/test_examples.py:342:12-38: Cannot index into `float` [bad-index]
- ERROR tests/test_examples.py:342:12-38: Cannot index into `int` [bad-index]
- ERROR tests/test_examples.py:342:12-38: Cannot index into `str` [bad-index]
- ERROR tests/test_examples.py:342:12-38: `None` is not subscriptable [unsupported-operation]
- ERROR tests/test_examples.py:1674:28-47: Cannot index into `str` [bad-index]
- ERROR tests/test_examples.py:1674:63-79: Type `bool` is not iterable [not-iterable]
- ERROR tests/test_examples.py:1674:63-79: Type `float` is not iterable [not-iterable]
- ERROR tests/test_examples.py:1674:63-79: Type `int` is not iterable [not-iterable]
- ERROR tests/test_examples.py:1674:63-79: Type `None` is not iterable [not-iterable]
- ::error file=cwltool/process.py,line=318,col=51,endLine=318,endColumn=58,title=Pyrefly bad-argument-type::Argument `MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None` is not assignable to parameter `obj` with type `MutableMapping[str, MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None] | MutableSequence[MutableMapping[str, MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None]] | None` in function `_collectDirEntries`
- ::error file=tests/test_examples.py,line=327,col=12,endLine=327,endColumn=28,title=Pyrefly bad-index::Cannot index into `bool`%0A  Object of class `bool` has no attribute `__getitem__`
- ::error file=tests/test_examples.py,line=327,col=12,endLine=327,endColumn=28,title=Pyrefly bad-index::Cannot index into `float`%0A  Object of class `float` has no attribute `__getitem__`
- ::error file=tests/test_examples.py,line=327,col=12,endLine=327,endColumn=28,title=Pyrefly bad-index::Cannot index into `int`%0A  Object of class `int` has no attribute `__getitem__`
- ::error file=tests/test_examples.py,line=327,col=12,endLine=327,endColumn=28,title=Pyrefly unsupported-operation::`None` is not subscriptable
- ::error file=tests/test_examples.py,line=327,col=12,endLine=327,endColumn=40,title=Pyrefly bad-index::Cannot index into `str`%0A  No matching overload found for function `str.__getitem__` called with arguments: (Literal['checksum'])%0A  Possible overloads:%0A  (key: SupportsIndex | slice[Any, Any, Any], /) -> LiteralString%0A  (key: SupportsIndex | slice[Any, Any, Any], /) -> str [closest match]
- ::error file=tests/test_examples.py,line=327,col=26,endLine=327,endColumn=27,title=Pyrefly bad-index::Cannot index into `MutableMapping[str, Unknown]`%0A  Argument `Literal[0]` is not assignable to parameter `key` with type `str` in function `typing.Mapping.__getitem__`
- ::error file=tests/test_examples.py,line=328,col=12,endLine=328,endColumn=28,title=Pyrefly bad-index::Cannot index into `bool`%0A  Object of class `bool` has no attribute `__getitem__`
- ::error file=tests/test_examples.py,line=328,col=12,endLine=328,endColumn=28,title=Pyrefly bad-index::Cannot index into `float`%0A  Object of class `float` has no attribute `__getitem__`
- ::error file=tests/test_examples.py,line=328,col=12,endLine=328,endColumn=28,title=Pyrefly bad-index::Cannot index into `int`%0A  Object of class `int` has no attribute `__getitem__`
- ::error file=tests/test_examples.py,line=328,col=12,endLine=328,endColumn=28,title=Pyrefly unsupported-operation::`None` is not subscriptable
- ::error file=tests/test_examples.py,line=328,col=26,endLine=328,endColumn=27,title=Pyrefly bad-index::Cannot index into `MutableMapping[str, Unknown]`%0A  Argument `Literal[1]` is not assignable to parameter `key` with type `str` in function `typing.Mapping.__getitem__`
- ::error file=tests/test_examples.py,line=329,col=12,endLine=329,endColumn=28,title=Pyrefly bad-index::Cannot index into `bool`%0A  Object of class `bool` has no attribute `__getitem__`
- ::error file=tests/test_examples.py,line=329,col=12,endLine=329,endColumn=28,title=Pyrefly bad-index::Cannot index into `float`%0A  Object of class `float` has no attribute `__getitem__`
- ::error file=tests/test_examples.py,line=329,col=12,endLine=329,endColumn=28,title=Pyrefly bad-index::Cannot index into `int`%0A  Object of class `int` has no attribute `__getitem__`
- ::error file=tests/test_examples.py,line=329,col=12,endLine=329,endColumn=28,title=Pyrefly unsupported-operation::`None` is not subscriptable
- ::error file=tests/test_examples.py,line=329,col=26,endLine=329,endColumn=27,title=Pyrefly bad-index::Cannot index into `MutableMapping[str, Unknown]`%0A  Argument `Literal[2]` is not assignable to parameter `key` with type `str` in function `typing.Mapping.__getitem__`
- ::error file=tests/test_examples.py,line=342,col=12,endLine=342,endColumn=38,title=Pyrefly bad-index::Cannot index into `MutableSequence[Unknown]`%0A  No matching overload found for function `typing.MutableSequence.__getitem__` called with arguments: (Literal['checksum'])%0A  Possible overloads:%0A  (index: int) -> Unknown [closest match]%0A  (index: slice[Any, Any, Any]) -> MutableSequence[Unknown]
- ::error file=tests/test_examples.py,line=342,col=12,endLine=342,endColumn=38,title=Pyrefly bad-index::Cannot index into `bool`%0A  Object of class `bool` has no attribute `__getitem__`
- ::error file=tests/test_examples.py,line=342,col=12,endLine=342,endColumn=38,title=Pyrefly bad-index::Cannot index into `float`%0A  Object of class `float` has no attribute `__getitem__`
- ::error file=tests/test_examples.py,line=342,col=12,endLine=342,endColumn=38,title=Pyrefly bad-index::Cannot index into `int`%0A  Object of class `int` has no attribute `__getitem__`
- ::error file=tests/test_examples.py,line=342,col=12,endLine=342,endColumn=38,title=Pyrefly bad-index::Cannot index into `str`%0A  No matching overload found for function `str.__getitem__` called with arguments: (Literal['checksum'])%0A  Possible overloads:%0A  (key: SupportsIndex | slice[Any, Any, Any], /) -> LiteralString%0A  (key: SupportsIndex | slice[Any, Any, Any], /) -> str [closest match]
- ::error file=tests/test_examples.py,line=342,col=12,endLine=342,endColumn=38,title=Pyrefly unsupported-operation::`None` is not subscriptable
- ::error file=tests/test_examples.py,line=1674,col=28,endLine=1674,endColumn=47,title=Pyrefly bad-index::Cannot index into `str`%0A  No matching overload found for function `str.__getitem__` called with arguments: (Literal['location'])%0A  Possible overloads:%0A  (key: SupportsIndex | slice[Any, Any, Any], /) -> LiteralString%0A  (key: SupportsIndex | slice[Any, Any, Any], /) -> str [closest match]
- ::error file=tests/test_examples.py,line=1674,col=63,endLine=1674,endColumn=79,title=Pyrefly not-iterable::Type `bool` is not iterable
- ::error file=tests/test_examples.py,line=1674,col=63,endLine=1674,endColumn=79,title=Pyrefly not-iterable::Type `float` is not iterable
- ::error file=tests/test_examples.py,line=1674,col=63,endLine=1674,endColumn=79,title=Pyrefly not-iterable::Type `int` is not iterable
- ::error file=tests/test_examples.py,line=1674,col=63,endLine=1674,endColumn=79,title=Pyrefly not-iterable::Type `None` is not iterable

mongo-python-driver (https://github.com/mongodb/mongo-python-driver)
- ERROR pymongo/asynchronous/cursor.py:686:25-31: No matching overload found for function `dict.__init__` called with arguments: (list[str | tuple[str, Mapping[str, Any] | int | str]] | tuple[*Sequence[str | tuple[str, Mapping[str, Any] | int | str]]]) [no-matching-overload]
+ ERROR pymongo/asynchronous/cursor.py:686:25-31: No matching overload found for function `dict.__init__` called with arguments: (tuple[*Sequence[str | tuple[str, Mapping[str, Any] | int | str]]]) [no-matching-overload]
- ERROR pymongo/asynchronous/cursor.py:708:25-31: No matching overload found for function `dict.__init__` called with arguments: (list[str | tuple[str, Mapping[str, Any] | int | str]] | tuple[*Sequence[str | tuple[str, Mapping[str, Any] | int | str]]]) [no-matching-overload]
+ ERROR pymongo/asynchronous/cursor.py:708:25-31: No matching overload found for function `dict.__init__` called with arguments: (tuple[*Sequence[str | tuple[str, Mapping[str, Any] | int | str]]]) [no-matching-overload]
- ERROR pymongo/synchronous/cursor.py:684:25-31: No matching overload found for function `dict.__init__` called with arguments: (list[str | tuple[str, Mapping[str, Any] | int | str]] | tuple[*Sequence[str | tuple[str, Mapping[str, Any] | int | str]]]) [no-matching-overload]

... (truncated 69 lines) ...```

jackulau and others added 6 commits January 13, 2026 18:59

Add inlay hints for tuple unpacking variables (facebook#2096)

31503b6

Merge branch 'facebook:main' into main

f39a52d

Merge branch 'facebook:main' into main

0edc18b

Merge branch 'facebook:main' into main

3f0559a

Merge branch 'facebook:main' into main

37438f9

Fix isinstance narrowing for unions with supertype members (facebook#…

4865e96

…2169)

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jackulau marked this pull request as draft January 26, 2026 19:13

Fix isinstance narrowing to use class hierarchy check (facebook#2169)

c019fb0

Added additional edge case tests for: - Subclass in union (dict with Mapping check) - Collection/Mapping hierarchy - Unrelated classes (Sequence/Mapping) - Superclass as isinstance target

jackulau marked this pull request as ready for review January 27, 2026 18:39

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Fix isinstance narrowing for unions with supertype members (#2169) #2222

Fix isinstance narrowing for unions with supertype members (#2169) #2222

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jackulau commented Jan 26, 2026

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yangdanny97 commented Jan 26, 2026 •

edited

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Fix isinstance narrowing for unions with supertype members (#2169) #2222

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Fix isinstance narrowing for unions with supertype members (#2169) #2222

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jackulau commented Jan 25, 2026

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yangdanny97 commented Jan 26, 2026 •

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