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Fix self-types in access to overloaded class methods on instances #7937

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Merged
merged 1 commit into from
Nov 12, 2019
Merged

Fix self-types in access to overloaded class methods on instances #7937

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10 changes: 5 additions & 5 deletions mypy/checkmember.py
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Original file line number Diff line number Diff line change
Expand Up @@ -204,9 +204,9 @@ def analyze_instance_member_access(name: str,
# TODO: use proper treatment of special methods on unions instead
# of this hack here and below (i.e. mx.self_type).
dispatched_type = meet.meet_types(mx.original_type, typ)
signature = check_self_arg(signature, dispatched_type, False, mx.context,
name, mx.msg)
signature = bind_self(signature, mx.self_type)
signature = check_self_arg(signature, dispatched_type, method.is_class,
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Oops.

mx.context, name, mx.msg)
signature = bind_self(signature, mx.self_type, is_classmethod=method.is_class)
typ = map_instance_to_supertype(typ, method.info)
member_type = expand_type_by_instance(signature, typ)
freeze_type_vars(member_type)
Expand Down Expand Up @@ -623,6 +623,8 @@ def f(self: S) -> T: ...
if not items:
return functype
new_items = []
if is_classmethod:
dispatched_arg_type = TypeType.make_normalized(dispatched_arg_type)
for item in items:
if not item.arg_types or item.arg_kinds[0] not in (ARG_POS, ARG_STAR):
# No positional first (self) argument (*args is okay).
Expand All @@ -632,8 +634,6 @@ def f(self: S) -> T: ...
return functype
else:
selfarg = item.arg_types[0]
if is_classmethod:
dispatched_arg_type = TypeType.make_normalized(dispatched_arg_type)
if subtypes.is_subtype(dispatched_arg_type, erase_typevars(erase_to_bound(selfarg))):
new_items.append(item)
if not new_items:
Expand Down
32 changes: 32 additions & 0 deletions test-data/unit/check-selftype.test
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Expand Up @@ -937,3 +937,35 @@ t: Type[Union[B, C]]
x = t.meth()[0]
reveal_type(x) # N: Revealed type is 'Union[__main__.B*, __main__.C*]'
[builtins fixtures/isinstancelist.pyi]

[case testSelfTypeClassMethodOverloadedOnInstance]
from typing import Optional, Type, TypeVar, overload, Union

Id = int

A = TypeVar("A", bound=AClass)

class AClass:
@overload
@classmethod
def delete(cls: Type[A], id: Id, id2: Id) -> Optional[int]: ...

@overload
@classmethod
def delete(cls: Type[A], id: A, id2: None = None) -> Optional[int]: ...

@classmethod
def delete(cls: Type[A], id: Union[A, Id], id2: Optional[Id] = None) -> Optional[int]:
...

def foo(x: Type[AClass]) -> None:
reveal_type(x.delete) # N: Revealed type is 'Overload(def (id: builtins.int, id2: builtins.int) -> builtins.int, def (id: __main__.AClass*, id2: None =) -> builtins.int)'
y = x()
reveal_type(y.delete) # N: Revealed type is 'Overload(def (id: builtins.int, id2: builtins.int) -> builtins.int, def (id: __main__.AClass*, id2: None =) -> builtins.int)'
y.delete(10, 20)
y.delete(y)

def bar(x: AClass) -> None:
reveal_type(x.delete) # N: Revealed type is 'Overload(def (id: builtins.int, id2: builtins.int) -> builtins.int, def (id: __main__.AClass*, id2: None =) -> builtins.int)'
x.delete(10, 20)
[builtins fixtures/classmethod.pyi]