test-data/unit/check-plugin-attrs.test

[case testAttrsSimple_no_empty]
import attr
@attr.s
class A:
    a = attr.ib()
    _b = attr.ib()
    c = attr.ib(18)
    _d = attr.ib(validator=None, default=18)
    E = 18

    def foo(self):
        return self.a
reveal_type(A)  # N: Revealed type is "def (a: Any, b: Any, c: Any =, d: Any =) -> __main__.A"
A(1, [2])
A(1, [2], '3', 4)
A(1, 2, 3, 4)
A(1, [2], '3', 4, 5)  # E: Too many arguments for "A"
[builtins fixtures/list.pyi]

[case testAttrsAnnotated]
import attr
from typing import List, ClassVar
@attr.s
class A:
    a: int = attr.ib()
    _b: List[int] = attr.ib()
    c: str = attr.ib('18')
    _d: int = attr.ib(validator=None, default=18)
    E = 7
    F: ClassVar[int] = 22
reveal_type(A)  # N: Revealed type is "def (a: builtins.int, b: builtins.list[builtins.int], c: builtins.str =, d: builtins.int =) -> __main__.A"
A(1, [2])
A(1, [2], '3', 4)
A(1, 2, 3, 4)  # E: Argument 2 to "A" has incompatible type "int"; expected "list[int]" # E: Argument 3 to "A" has incompatible type "int"; expected "str"
A(1, [2], '3', 4, 5)  # E: Too many arguments for "A"
[builtins fixtures/list.pyi]

[case testAttrsTypeComments]
import attr
from typing import List, ClassVar
@attr.s
class A:
    a = attr.ib()   # type: int
    _b = attr.ib()  # type: List[int]
    c = attr.ib('18') # type: str
    _d = attr.ib(validator=None, default=18) # type: int
    E = 7
    F: ClassVar[int] = 22
reveal_type(A)  # N: Revealed type is "def (a: builtins.int, b: builtins.list[builtins.int], c: builtins.str =, d: builtins.int =) -> __main__.A"
A(1, [2])
A(1, [2], '3', 4)
A(1, 2, 3, 4)  # E: Argument 2 to "A" has incompatible type "int"; expected "list[int]" # E: Argument 3 to "A" has incompatible type "int"; expected "str"
A(1, [2], '3', 4, 5)  # E: Too many arguments for "A"
[builtins fixtures/list.pyi]

[case testAttrsAutoAttribs]
import attr
from typing import List, ClassVar
@attr.s(auto_attribs=True)
class A:
    a: int
    _b: List[int]
    c: str = '18'
    _d: int = attr.ib(validator=None, default=18)
    E = 7
    F: ClassVar[int] = 22
reveal_type(A)  # N: Revealed type is "def (a: builtins.int, b: builtins.list[builtins.int], c: builtins.str =, d: builtins.int =) -> __main__.A"
A(1, [2])
A(1, [2], '3', 4)
A(1, 2, 3, 4)  # E: Argument 2 to "A" has incompatible type "int"; expected "list[int]" # E: Argument 3 to "A" has incompatible type "int"; expected "str"
A(1, [2], '3', 4, 5)  # E: Too many arguments for "A"
[builtins fixtures/list.pyi]

[case testAttrsUntypedNoUntypedDefs]
# flags: --disallow-untyped-defs
import attr
@attr.s
class A:
    a = attr.ib()  # E: Need type annotation for "a"
    _b = attr.ib()  # E: Need type annotation for "_b"
    c = attr.ib(18)  # E: Need type annotation for "c"
    _d = attr.ib(validator=None, default=18)   # E: Need type annotation for "_d"
    E = 18
[builtins fixtures/bool.pyi]

[case testAttrsWrongReturnValue]
import attr
@attr.s
class A:
    x: int = attr.ib(8)
    def foo(self) -> str:
        return self.x  # E: Incompatible return value type (got "int", expected "str")
@attr.s
class B:
    x = attr.ib(8)  # type: int
    def foo(self) -> str:
        return self.x  # E: Incompatible return value type (got "int", expected "str")
@attr.dataclass
class C:
    x: int = 8
    def foo(self) -> str:
        return self.x  # E: Incompatible return value type (got "int", expected "str")
@attr.s
class D:
    x = attr.ib(8, type=int)
    def foo(self) -> str:
        return self.x  # E: Incompatible return value type (got "int", expected "str")
[builtins fixtures/bool.pyi]

[case testAttrsSeriousNames]
from attr import attrib, attrs
from typing import List
@attrs(init=True)
class A:
    a = attrib()
    _b: List[int] = attrib()
    c = attrib(18)
    _d = attrib(validator=None, default=18)
    CLASS_VAR = 18
reveal_type(A)  # N: Revealed type is "def (a: Any, b: builtins.list[builtins.int], c: Any =, d: Any =) -> __main__.A"
A(1, [2])
A(1, [2], '3', 4)
A(1, 2, 3, 4)  # E: Argument 2 to "A" has incompatible type "int"; expected "list[int]"
A(1, [2], '3', 4, 5)  # E: Too many arguments for "A"
[builtins fixtures/list.pyi]

[case testAttrsDefaultErrors]
import attr
@attr.s
class A:
    x = attr.ib(default=17)
    y = attr.ib()  # E: Non-default attributes not allowed after default attributes.
@attr.s(auto_attribs=True)
class B:
    x: int = 17
    y: int # E: Non-default attributes not allowed after default attributes.
@attr.s(auto_attribs=True)
class C:
    x: int = attr.ib(default=17)
    y: int # E: Non-default attributes not allowed after default attributes.
@attr.s
class D:
    x = attr.ib()
    y = attr.ib() # E: Non-default attributes not allowed after default attributes.

    @x.default
    def foo(self):
        return 17
[builtins fixtures/bool.pyi]

[case testAttrsNotBooleans]
import attr
x = True
@attr.s(cmp=x)  # E: "cmp" argument must be a True, False, or None literal
class A:
    a = attr.ib(init=x)  # E: "init" argument must be a True or False literal
[builtins fixtures/bool.pyi]

[case testAttrsInitFalse]
from attr import attrib, attrs
@attrs(auto_attribs=True, init=False)
class A:
    a: int
    _b: int
    c: int = 18
    _d: int = attrib(validator=None, default=18)
reveal_type(A)  # N: Revealed type is "def () -> __main__.A"
A()
A(1, [2])  # E: Too many arguments for "A"
A(1, [2], '3', 4)  # E: Too many arguments for "A"
[builtins fixtures/list.pyi]

[case testAttrsInitAttribFalse]
from attr import attrib, attrs
@attrs
class A:
    a = attrib(init=False)
    b = attrib()
reveal_type(A)  # N: Revealed type is "def (b: Any) -> __main__.A"
[builtins fixtures/bool.pyi]

[case testAttrsCmpTrue]
from attr import attrib, attrs
@attrs(auto_attribs=True)
class A:
    a: int
reveal_type(A)  # N: Revealed type is "def (a: builtins.int) -> __main__.A"
reveal_type(A.__lt__)  # N: Revealed type is "def [_AT] (self: _AT`3, other: _AT`3) -> builtins.bool"
reveal_type(A.__le__)  # N: Revealed type is "def [_AT] (self: _AT`4, other: _AT`4) -> builtins.bool"
reveal_type(A.__gt__)  # N: Revealed type is "def [_AT] (self: _AT`5, other: _AT`5) -> builtins.bool"
reveal_type(A.__ge__)  # N: Revealed type is "def [_AT] (self: _AT`6, other: _AT`6) -> builtins.bool"

A(1) < A(2)
A(1) <= A(2)
A(1) > A(2)
A(1) >= A(2)
A(1) == A(2)
A(1) != A(2)

A(1) < 1  # E: Unsupported operand types for < ("A" and "int")
A(1) <= 1  # E: Unsupported operand types for <= ("A" and "int")
A(1) > 1  # E: Unsupported operand types for > ("A" and "int")
A(1) >= 1  # E: Unsupported operand types for >= ("A" and "int")
A(1) == 1
A(1) != 1

1 < A(1)  # E: Unsupported operand types for > ("A" and "int")
1 <= A(1)  # E: Unsupported operand types for >= ("A" and "int")
1 > A(1)  # E: Unsupported operand types for < ("A" and "int")
1 >= A(1)  # E: Unsupported operand types for <= ("A" and "int")
1 == A(1)
1 != A(1)
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsEqFalse]
from attr import attrib, attrs
@attrs(auto_attribs=True, eq=False)
class A:
    a: int
reveal_type(A)  # N: Revealed type is "def (a: builtins.int) -> __main__.A"
reveal_type(A.__eq__)  # N: Revealed type is "def (builtins.object, builtins.object) -> builtins.bool"
reveal_type(A.__ne__)  # N: Revealed type is "def (builtins.object, builtins.object) -> builtins.bool"

A(1) < A(2)  # E: Unsupported left operand type for < ("A")
A(1) <= A(2)  # E: Unsupported left operand type for <= ("A")
A(1) > A(2)  # E: Unsupported left operand type for > ("A")
A(1) >= A(2)  # E: Unsupported left operand type for >= ("A")
A(1) == A(2)
A(1) != A(2)

A(1) < 1  # E: Unsupported left operand type for < ("A")
A(1) <= 1  # E: Unsupported left operand type for <= ("A")
A(1) > 1  # E: Unsupported left operand type for > ("A")
A(1) >= 1  # E: Unsupported left operand type for >= ("A")
A(1) == 1
A(1) != 1

1 < A(1)  # E: Unsupported left operand type for < ("int")
1 <= A(1)  # E: Unsupported left operand type for <= ("int")
1 > A(1)  # E: Unsupported left operand type for > ("int")
1 >= A(1)  # E: Unsupported left operand type for >= ("int")
1 == A(1)
1 != A(1)
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsOrderFalse]
from attr import attrib, attrs
@attrs(auto_attribs=True, order=False)
class A:
    a: int
reveal_type(A)  # N: Revealed type is "def (a: builtins.int) -> __main__.A"

A(1) < A(2)  # E: Unsupported left operand type for < ("A")
A(1) <= A(2)  # E: Unsupported left operand type for <= ("A")
A(1) > A(2)  # E: Unsupported left operand type for > ("A")
A(1) >= A(2)  # E: Unsupported left operand type for >= ("A")
A(1) == A(2)
A(1) != A(2)

A(1) < 1  # E: Unsupported left operand type for < ("A")
A(1) <= 1  # E: Unsupported left operand type for <= ("A")
A(1) > 1  # E: Unsupported left operand type for > ("A")
A(1) >= 1  # E: Unsupported left operand type for >= ("A")
A(1) == 1
A(1) != 1

1 < A(1)  # E: Unsupported left operand type for < ("int")
1 <= A(1)  # E: Unsupported left operand type for <= ("int")
1 > A(1)  # E: Unsupported left operand type for > ("int")
1 >= A(1)  # E: Unsupported left operand type for >= ("int")
1 == A(1)
1 != A(1)
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsCmpEqOrderValues]
from attr import attrib, attrs
@attrs(cmp=True)
class DeprecatedTrue:
   ...

@attrs(cmp=False)
class DeprecatedFalse:
   ...

@attrs(cmp=False, eq=True)  # E: Don't mix "cmp" with "eq" and "order"
class Mixed:
   ...

@attrs(order=True, eq=False)  # E: eq must be True if order is True
class Confused:
   ...
[builtins fixtures/plugin_attrs.pyi]


[case testAttrsInheritance]
import attr
@attr.s
class A:
    a: int = attr.ib()
@attr.s
class B:
    b: str = attr.ib()
@attr.s
class C(A, B):
    c: bool = attr.ib()
reveal_type(C)  # N: Revealed type is "def (a: builtins.int, b: builtins.str, c: builtins.bool) -> __main__.C"
[builtins fixtures/bool.pyi]

[case testAttrsNestedInClasses]
import attr
@attr.s
class C:
    y = attr.ib()
    @attr.s
    class D:
        x: int = attr.ib()
reveal_type(C)  # N: Revealed type is "def (y: Any) -> __main__.C"
reveal_type(C.D)  # N: Revealed type is "def (x: builtins.int) -> __main__.C.D"
[builtins fixtures/bool.pyi]

[case testAttrsInheritanceOverride]
import attr

@attr.s
class A:
    a: int = attr.ib()
    x: int = attr.ib()

@attr.s
class B(A):
    b: str = attr.ib()
    x: int = attr.ib(default=22)

@attr.s
class C(B):
    c: bool = attr.ib()  # No error here because the x below overwrites the x above.
    x: int = attr.ib()

reveal_type(A)  # N: Revealed type is "def (a: builtins.int, x: builtins.int) -> __main__.A"
reveal_type(B)  # N: Revealed type is "def (a: builtins.int, b: builtins.str, x: builtins.int =) -> __main__.B"
reveal_type(C)  # N: Revealed type is "def (a: builtins.int, b: builtins.str, c: builtins.bool, x: builtins.int) -> __main__.C"
[builtins fixtures/bool.pyi]

[case testAttrsTypeEquals]
import attr

@attr.s
class A:
    a = attr.ib(type=int)
    b = attr.ib(18, type=int)
reveal_type(A) # N: Revealed type is "def (a: builtins.int, b: builtins.int =) -> __main__.A"
[builtins fixtures/bool.pyi]

[case testAttrsFrozen]
import attr

@attr.s(frozen=True)
class A:
    a = attr.ib()

a = A(5)
a.a = 16  # E: Property "a" defined in "A" is read-only
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsNextGenFrozen]
from attr import frozen, field

@frozen
class A:
    a = field()

a = A(5)
a.a = 16  # E: Property "a" defined in "A" is read-only
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsNextGenDetect]
from attr import define, field

@define
class A:
    a = field()

@define
class B:
    a: int

@define
class C:
    a: int = field()
    b = field()

@define
class D:
    a: int
    b = field()

reveal_type(A)  # N: Revealed type is "def (a: Any) -> __main__.A"
reveal_type(B)  # N: Revealed type is "def (a: builtins.int) -> __main__.B"
reveal_type(C)  # N: Revealed type is "def (a: builtins.int, b: Any) -> __main__.C"
reveal_type(D)  # N: Revealed type is "def (b: Any) -> __main__.D"

[builtins fixtures/bool.pyi]

[case testAttrsOldPackage]
import attr
@attr.s(auto_attribs=True)
class A:
    a: int = attr.ib()
    b: bool

@attr.s(auto_attribs=True, frozen=True)
class B:
    a: bool
    b: int

@attr.s
class C:
    a = attr.ib(type=int)

reveal_type(A)  # N: Revealed type is "def (a: builtins.int, b: builtins.bool) -> __main__.A"
reveal_type(B)  # N: Revealed type is "def (a: builtins.bool, b: builtins.int) -> __main__.B"
reveal_type(C)  # N: Revealed type is "def (a: builtins.int) -> __main__.C"

[builtins fixtures/plugin_attrs.pyi]

[case testAttrsDataClass]
import attr
from typing import List, ClassVar
@attr.dataclass
class A:
    a: int
    _b: List[str]
    c: str = '18'
    _d: int = attr.ib(validator=None, default=18)
    E = 7
    F: ClassVar[int] = 22
reveal_type(A)  # N: Revealed type is "def (a: builtins.int, b: builtins.list[builtins.str], c: builtins.str =, d: builtins.int =) -> __main__.A"
A(1, ['2'])
[builtins fixtures/list.pyi]

[case testAttrsTypeAlias]
from typing import List
import attr
Alias = List[int]
@attr.s(auto_attribs=True)
class A:
    Alias2 = List[str]
    x: Alias
    y: Alias2 = attr.ib()
reveal_type(A) # N: Revealed type is "def (x: builtins.list[builtins.int], y: builtins.list[builtins.str]) -> __main__.A"
[builtins fixtures/list.pyi]

[case testAttrsGeneric]
from typing import TypeVar, Generic, List
import attr
T = TypeVar('T')
@attr.s(auto_attribs=True)
class A(Generic[T]):
    x: List[T]
    y: T = attr.ib()
    def foo(self) -> List[T]:
        return [self.y]
    def bar(self) -> T:
        return self.x[0]
    def problem(self) -> T:
        return self.x  # E: Incompatible return value type (got "list[T]", expected "T")
reveal_type(A) # N: Revealed type is "def [T] (x: builtins.list[T`1], y: T`1) -> __main__.A[T`1]"
a = A([1], 2)
reveal_type(a)  # N: Revealed type is "__main__.A[builtins.int]"
reveal_type(a.x)  # N: Revealed type is "builtins.list[builtins.int]"
reveal_type(a.y)  # N: Revealed type is "builtins.int"

A(['str'], 7)  # E: Cannot infer value of type parameter "T" of "A"
A([1], '2')  # E: Cannot infer value of type parameter "T" of "A"

[builtins fixtures/list.pyi]

[case testAttrsGenericWithConverter]
from typing import TypeVar, Generic, List, Iterable, Iterator, Callable
import attr
T = TypeVar('T')

def int_gen() -> Iterator[int]:
    yield 1

def list_converter(x: Iterable[T]) -> List[T]:
    return list(x)

@attr.s(auto_attribs=True)
class A(Generic[T]):
    x: List[T] = attr.ib(converter=list_converter)
    y: T = attr.ib()
    def foo(self) -> List[T]:
        return [self.y]
    def bar(self) -> T:
        return self.x[0]
    def problem(self) -> T:
        return self.x  # E: Incompatible return value type (got "list[T]", expected "T")
reveal_type(A) # N: Revealed type is "def [T] (x: typing.Iterable[T`1], y: T`1) -> __main__.A[T`1]"
a1 = A([1], 2)
reveal_type(a1)  # N: Revealed type is "__main__.A[builtins.int]"
reveal_type(a1.x)  # N: Revealed type is "builtins.list[builtins.int]"
reveal_type(a1.y)  # N: Revealed type is "builtins.int"

a2 = A(int_gen(), 2)
reveal_type(a2)  # N: Revealed type is "__main__.A[builtins.int]"
reveal_type(a2.x)  # N: Revealed type is "builtins.list[builtins.int]"
reveal_type(a2.y)  # N: Revealed type is "builtins.int"


def get_int() -> int:
    return 1

class Other(Generic[T]):
    def __init__(self, x: T) -> None:
        pass

@attr.s(auto_attribs=True)
class B(Generic[T]):
    x: Other[Callable[..., T]] = attr.ib(converter=Other[Callable[..., T]])

b1 = B(get_int)
reveal_type(b1)  # N: Revealed type is "__main__.B[builtins.int]"
reveal_type(b1.x)  # N: Revealed type is "__main__.Other[def (*Any, **Any) -> builtins.int]"

[builtins fixtures/list.pyi]


[case testAttrsUntypedGenericInheritance]
from typing import Generic, TypeVar
import attr

T = TypeVar("T")

@attr.s(auto_attribs=True)
class Base(Generic[T]):
    attr: T

@attr.s(auto_attribs=True)
class Sub(Base):
    pass

sub = Sub(attr=1)
reveal_type(sub)  # N: Revealed type is "__main__.Sub"
reveal_type(sub.attr)  # N: Revealed type is "Any"

[builtins fixtures/bool.pyi]


[case testAttrsGenericInheritance]
from typing import Generic, TypeVar
import attr

S = TypeVar("S")
T = TypeVar("T")

@attr.s(auto_attribs=True)
class Base(Generic[T]):
    attr: T

@attr.s(auto_attribs=True)
class Sub(Base[S]):
    pass

sub_int = Sub[int](attr=1)
reveal_type(sub_int)  # N: Revealed type is "__main__.Sub[builtins.int]"
reveal_type(sub_int.attr)  # N: Revealed type is "builtins.int"

sub_str = Sub[str](attr='ok')
reveal_type(sub_str)  # N: Revealed type is "__main__.Sub[builtins.str]"
reveal_type(sub_str.attr)  # N: Revealed type is "builtins.str"

[builtins fixtures/bool.pyi]


[case testAttrsGenericInheritance2]
from typing import Generic, TypeVar
import attr

T1 = TypeVar("T1")
T2 = TypeVar("T2")
T3 = TypeVar("T3")

@attr.s(auto_attribs=True)
class Base(Generic[T1, T2, T3]):
    one: T1
    two: T2
    three: T3

@attr.s(auto_attribs=True)
class Sub(Base[int, str, float]):
    pass

sub = Sub(one=1, two='ok', three=3.14)
reveal_type(sub)  # N: Revealed type is "__main__.Sub"
reveal_type(sub.one)  # N: Revealed type is "builtins.int"
reveal_type(sub.two)  # N: Revealed type is "builtins.str"
reveal_type(sub.three)  # N: Revealed type is "builtins.float"

[builtins fixtures/bool.pyi]


[case testAttrsGenericInheritance3]
import attr
from typing import Any, Callable, Generic, TypeVar, List

T = TypeVar("T")
S = TypeVar("S")

@attr.s(auto_attribs=True)
class Parent(Generic[T]):
    f: Callable[[T], Any]

@attr.s(auto_attribs=True)
class Child(Parent[T]): ...

class A: ...
def func(obj: A) -> bool: ...

reveal_type(Child[A](func).f)  # N: Revealed type is "def (__main__.A) -> Any"

@attr.s(auto_attribs=True)
class Parent2(Generic[T]):
    a: List[T]

@attr.s(auto_attribs=True)
class Child2(Generic[T, S], Parent2[S]):
    b: List[T]

reveal_type(Child2([A()], [1]).a)  # N: Revealed type is "builtins.list[__main__.A]"
reveal_type(Child2[int, A]([A()], [1]).b)  # N: Revealed type is "builtins.list[builtins.int]"
[builtins fixtures/list.pyi]

[case testAttrsMultiGenericInheritance]
from typing import Generic, TypeVar
import attr

T = TypeVar("T")

@attr.s(auto_attribs=True, eq=False)
class Base(Generic[T]):
    base_attr: T

S = TypeVar("S")

@attr.s(auto_attribs=True, eq=False)
class Middle(Base[int], Generic[S]):
    middle_attr: S

@attr.s(auto_attribs=True, eq=False)
class Sub(Middle[str]):
    pass

sub = Sub(base_attr=1, middle_attr='ok')
reveal_type(sub)  # N: Revealed type is "__main__.Sub"
reveal_type(sub.base_attr)  # N: Revealed type is "builtins.int"
reveal_type(sub.middle_attr)  # N: Revealed type is "builtins.str"

[builtins fixtures/bool.pyi]


[case testAttrsGenericClassmethod]
from typing import TypeVar, Generic, Optional
import attr
T = TypeVar('T')
@attr.s(auto_attribs=True)
class A(Generic[T]):
    x: Optional[T]
    @classmethod
    def clsmeth(cls) -> None:
       reveal_type(cls)  # N: Revealed type is "type[__main__.A[T`1]]"

[builtins fixtures/classmethod.pyi]

[case testAttrsForwardReference]
# flags: --no-strict-optional
import attr
@attr.s(auto_attribs=True)
class A:
    parent: 'B'

@attr.s(auto_attribs=True)
class B:
    parent: A

reveal_type(A) # N: Revealed type is "def (parent: __main__.B) -> __main__.A"
reveal_type(B) # N: Revealed type is "def (parent: __main__.A) -> __main__.B"
A(B(None))
[builtins fixtures/list.pyi]

[case testAttrsForwardReferenceInClass]
# flags: --no-strict-optional
import attr
@attr.s(auto_attribs=True)
class A:
    parent: A.B

    @attr.s(auto_attribs=True)
    class B:
        parent: A

reveal_type(A) # N: Revealed type is "def (parent: __main__.A.B) -> __main__.A"
reveal_type(A.B) # N: Revealed type is "def (parent: __main__.A) -> __main__.A.B"
A(A.B(None))
[builtins fixtures/list.pyi]

[case testAttrsImporting]
from helper import A
reveal_type(A)  # N: Revealed type is "def (a: builtins.int, b: builtins.str) -> helper.A"
[file helper.py]
import attr
@attr.s(auto_attribs=True)
class A:
   a: int
   b: str = attr.ib()
[builtins fixtures/list.pyi]

[case testAttrsOtherMethods]
import attr
@attr.s(auto_attribs=True)
class A:
    a: int
    b: str = attr.ib()
    @classmethod
    def new(cls) -> A:
       reveal_type(cls)  # N: Revealed type is "type[__main__.A]"
       return cls(6, 'hello')
    @classmethod
    def bad(cls) -> A:
        return cls(17)  # E: Missing positional argument "b" in call to "A"
    def foo(self) -> int:
       return self.a
reveal_type(A)  # N: Revealed type is "def (a: builtins.int, b: builtins.str) -> __main__.A"
a = A.new()
reveal_type(a.foo) # N: Revealed type is "def () -> builtins.int"
[builtins fixtures/classmethod.pyi]

[case testAttrsOtherOverloads]
import attr
from typing import overload, Union

@attr.s
class A:
    a = attr.ib()
    b = attr.ib(default=3)

    @classmethod
    def other(cls) -> str:
        return "..."

    @overload
    @classmethod
    def foo(cls, x: int) -> int: ...

    @overload
    @classmethod
    def foo(cls, x: str) -> str: ...

    @classmethod
    def foo(cls, x: Union[int, str]) -> Union[int, str]:
        reveal_type(cls)            # N: Revealed type is "type[__main__.A]"
        reveal_type(cls.other())    # N: Revealed type is "builtins.str"
        return x

reveal_type(A.foo(3))      # N: Revealed type is "builtins.int"
reveal_type(A.foo("foo"))  # N: Revealed type is "builtins.str"

[builtins fixtures/classmethod.pyi]

[case testAttrsDefaultDecorator]
import attr
@attr.s
class C(object):
    x: int = attr.ib(default=1)
    y: int = attr.ib()
    @y.default
    def name_does_not_matter(self):
        return self.x + 1
C()
[builtins fixtures/list.pyi]

[case testAttrsValidatorDecorator]
import attr
@attr.s
class C(object):
    x = attr.ib()
    @x.validator
    def check(self, attribute, value):
        if value > 42:
            raise ValueError("x must be smaller or equal to 42")
C(42)
C(43)
[builtins fixtures/exception.pyi]

[case testAttrsLocalVariablesInClassMethod]
import attr
@attr.s(auto_attribs=True)
class A:
    a: int
    b: int = attr.ib()
    @classmethod
    def new(cls, foo: int) -> A:
       a = foo
       b = a
       return cls(a, b)
[builtins fixtures/classmethod.pyi]

[case testAttrsUnionForward]
import attr
from typing import Union, List

@attr.s(auto_attribs=True)
class A:
    frob: List['AOrB']

class B:
   pass

AOrB = Union[A, B]

reveal_type(A)  # N: Revealed type is "def (frob: builtins.list[__main__.A | __main__.B]) -> __main__.A"
reveal_type(B)  # N: Revealed type is "def () -> __main__.B"

A([B()])
[builtins fixtures/list.pyi]

[case testAttrsUsingConvert]
import attr

def convert(s:int) -> str:
    return 'hello'

@attr.s
class C:
    x: str = attr.ib(convert=convert)  # E: convert is deprecated, use converter

# Because of the convert the __init__ takes an int, but the variable is a str.
reveal_type(C)  # N: Revealed type is "def (x: builtins.int) -> __main__.C"
reveal_type(C(15).x)  # N: Revealed type is "builtins.str"
[builtins fixtures/list.pyi]

[case testAttrsUsingConverter]
import attr
import helper

def converter2(s:int) -> str:
    return 'hello'

@attr.s
class C:
    x: str = attr.ib(converter=helper.converter)
    y: str = attr.ib(converter=converter2)

# Because of the converter the __init__ takes an int, but the variable is a str.
reveal_type(C)  # N: Revealed type is "def (x: builtins.int, y: builtins.int) -> __main__.C"
reveal_type(C(15, 16).x)  # N: Revealed type is "builtins.str"
[file helper.py]
def converter(s:int) -> str:
    return 'hello'
[builtins fixtures/list.pyi]

[case testAttrsUsingConvertAndConverter]
import attr

def converter(s:int) -> str:
    return 'hello'

@attr.s
class C:
    x: str = attr.ib(converter=converter, convert=converter)  # E: Can't pass both "convert" and "converter".

[builtins fixtures/list.pyi]

[case testAttrsUsingBadConverter]
# flags: --no-strict-optional
import attr
from typing import overload
@overload
def bad_overloaded_converter(x: int, y: int) -> int:
    ...
@overload
def bad_overloaded_converter(x: str, y: str) -> str:
    ...
def bad_overloaded_converter(x, y=7):
    return x
def bad_converter() -> str:
    return ''
@attr.dataclass
class A:
    bad: str = attr.ib(converter=bad_converter)
    bad_overloaded: int = attr.ib(converter=bad_overloaded_converter)
reveal_type(A)
[out]
main:16: error: Cannot determine __init__ type from converter
main:16: error: Argument "converter" has incompatible type "Callable[[], str]"; expected "Callable[[Any], str]"
main:17: error: Cannot determine __init__ type from converter
main:17: error: Argument "converter" has incompatible type overloaded function; expected "Callable[[Any], int]"
main:18: note: Revealed type is "def (bad: Any, bad_overloaded: Any) -> __main__.A"
[builtins fixtures/list.pyi]

[case testAttrsUsingBadConverterReprocess]
# flags: --no-strict-optional
import attr
from typing import overload
forward: 'A'
@overload
def bad_overloaded_converter(x: int, y: int) -> int:
    ...
@overload
def bad_overloaded_converter(x: str, y: str) -> str:
    ...
def bad_overloaded_converter(x, y=7):
    return x
def bad_converter() -> str:
    return ''
@attr.dataclass
class A:
    bad: str = attr.ib(converter=bad_converter)
    bad_overloaded: int = attr.ib(converter=bad_overloaded_converter)
reveal_type(A)
[out]
main:17: error: Cannot determine __init__ type from converter
main:17: error: Argument "converter" has incompatible type "Callable[[], str]"; expected "Callable[[Any], str]"
main:18: error: Cannot determine __init__ type from converter
main:18: error: Argument "converter" has incompatible type overloaded function; expected "Callable[[Any], int]"
main:19: note: Revealed type is "def (bad: Any, bad_overloaded: Any) -> __main__.A"
[builtins fixtures/list.pyi]

[case testAttrsUsingUnsupportedConverter]
import attr
class Thing:
    def do_it(self, int) -> str:
        ...
thing = Thing()
def factory(default: int):
   ...
@attr.s
class C:
    x: str = attr.ib(converter=thing.do_it)  # E: Unsupported converter, only named functions, types and lambdas are currently supported
    y: str = attr.ib(converter=lambda x: x)
    z: str = attr.ib(converter=factory(8))   # E: Unsupported converter, only named functions, types and lambdas are currently supported
reveal_type(C)  # N: Revealed type is "def (x: Any, y: Any, z: Any) -> __main__.C"
[builtins fixtures/list.pyi]

[case testAttrsUsingConverterAndSubclass]
import attr

def converter(s:int) -> str:
    return 'hello'

@attr.s
class C:
    x: str = attr.ib(converter=converter)

@attr.s
class A(C):
    pass

# Because of the convert the __init__ takes an int, but the variable is a str.
reveal_type(A)  # N: Revealed type is "def (x: builtins.int) -> __main__.A"
reveal_type(A(15).x)  # N: Revealed type is "builtins.str"
[builtins fixtures/list.pyi]

[case testAttrsUsingConverterWithTypes]
from typing import overload
import attr

@attr.dataclass
class A:
    x: str

@attr.s
class C:
    x: complex = attr.ib(converter=complex)
    y: int = attr.ib(converter=int)
    z: A = attr.ib(converter=A)

o = C("1", "2", "3")
o = C(1, 2, "3")
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsCmpWithSubclasses]
import attr
@attr.s
class A: pass
@attr.s
class B: pass
@attr.s
class C(A, B): pass
@attr.s
class D(A): pass

reveal_type(A.__lt__)  # N: Revealed type is "def [_AT] (self: _AT`5, other: _AT`5) -> builtins.bool"
reveal_type(B.__lt__)  # N: Revealed type is "def [_AT] (self: _AT`6, other: _AT`6) -> builtins.bool"
reveal_type(C.__lt__)  # N: Revealed type is "def [_AT] (self: _AT`7, other: _AT`7) -> builtins.bool"
reveal_type(D.__lt__)  # N: Revealed type is "def [_AT] (self: _AT`8, other: _AT`8) -> builtins.bool"

A() < A()
B() < B()
A() < B() # E: Unsupported operand types for < ("A" and "B")

C() > A()
C() > B()
C() > C()
C() > D() # E: Unsupported operand types for > ("C" and "D")

D() >= A()
D() >= B()  # E: Unsupported operand types for >= ("D" and "B")
D() >= C()  # E: Unsupported operand types for >= ("D" and "C")
D() >= D()

A() <= 1  # E: Unsupported operand types for <= ("A" and "int")
B() <= 1  # E: Unsupported operand types for <= ("B" and "int")
C() <= 1  # E: Unsupported operand types for <= ("C" and "int")
D() <= 1  # E: Unsupported operand types for <= ("D" and "int")

[builtins fixtures/list.pyi]

[case testAttrsComplexSuperclass]
import attr
@attr.s
class C:
    x: int = attr.ib(default=1)
    y: int = attr.ib()
    @y.default
    def name_does_not_matter(self):
        return self.x + 1
@attr.s
class A(C):
    z: int = attr.ib(default=18)
reveal_type(C)  # N: Revealed type is "def (x: builtins.int =, y: builtins.int =) -> __main__.C"
reveal_type(A)  # N: Revealed type is "def (x: builtins.int =, y: builtins.int =, z: builtins.int =) -> __main__.A"
[builtins fixtures/list.pyi]

[case testAttrsMultiAssign]
import attr
@attr.s
class A:
   x, y, z = attr.ib(), attr.ib(type=int), attr.ib(default=17)
reveal_type(A) # N: Revealed type is "def (x: Any, y: builtins.int, z: Any =) -> __main__.A"
[builtins fixtures/list.pyi]

[case testAttrsMultiAssign2]
import attr
@attr.s
class A:
   x = y = z = attr.ib()  # E: Too many names for one attribute
[builtins fixtures/list.pyi]

[case testAttrsPrivateInit]
import attr
@attr.s
class C(object):
    _x = attr.ib(init=False, default=42)
C()
C(_x=42)  # E: Unexpected keyword argument "_x" for "C"
[builtins fixtures/list.pyi]

[case testAttrsAliasForInit]
from attrs import define, field

@define
class C1:
    _x: int = field(alias="x1")

c1 = C1(x1=42)
reveal_type(c1._x)  # N: Revealed type is "builtins.int"
c1.x1  # E: "C1" has no attribute "x1"
C1(_x=42)  # E: Unexpected keyword argument "_x" for "C1"

alias = "x2"
@define
class C2:
    _x: int = field(alias=alias)  # E: "alias" argument to attrs field must be a string literal

@define
class C3:
    _x: int = field(alias="_x")

c3 = C3(_x=1)
reveal_type(c3._x)  # N: Revealed type is "builtins.int"
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsAutoMustBeAll]
import attr
@attr.s(auto_attribs=True)
class A:
   a: int
   b = 17
   # The following forms are not allowed with auto_attribs=True
   c = attr.ib()  # E: Need type annotation for "c"
   d, e = attr.ib(), attr.ib() # E: Need type annotation for "d" # E: Need type annotation for "e"
   f = g = attr.ib()  # E: Need type annotation for "f" # E: Need type annotation for "g"
[builtins fixtures/bool.pyi]

[case testAttrsRepeatedName]
import attr
@attr.s
class A:
   a = attr.ib(default=8)
   b = attr.ib()
   a = attr.ib()
reveal_type(A)  # N: Revealed type is "def (b: Any, a: Any) -> __main__.A"
@attr.s
class B:
   a: int = attr.ib(default=8)
   b: int = attr.ib()
   a: int = attr.ib()  # E: Name "a" already defined on line 10
reveal_type(B)  # N: Revealed type is "def (b: builtins.int, a: builtins.int) -> __main__.B"
@attr.s(auto_attribs=True)
class C:
   a: int = 8
   b: int
   a: int = attr.ib()  # E: Name "a" already defined on line 16
reveal_type(C)  # N: Revealed type is "def (a: builtins.int, b: builtins.int) -> __main__.C"
[builtins fixtures/bool.pyi]

[case testAttrsFrozenSubclass]
import attr

@attr.dataclass
class NonFrozenBase:
    a: int

@attr.dataclass(frozen=True)
class FrozenBase:
    a: int

@attr.dataclass(frozen=True)
class FrozenNonFrozen(NonFrozenBase):
    b: int

@attr.dataclass(frozen=True)
class FrozenFrozen(FrozenBase):
    b: int

@attr.dataclass
class NonFrozenFrozen(FrozenBase):
    b: int

# Make sure these are untouched
non_frozen_base = NonFrozenBase(1)
non_frozen_base.a = 17
frozen_base = FrozenBase(1)
frozen_base.a = 17  # E: Property "a" defined in "FrozenBase" is read-only

a = FrozenNonFrozen(1, 2)
a.a = 17  # E: Property "a" defined in "FrozenNonFrozen" is read-only
a.b = 17  # E: Property "b" defined in "FrozenNonFrozen" is read-only

b = FrozenFrozen(1, 2)
b.a = 17  # E: Property "a" defined in "FrozenFrozen" is read-only
b.b = 17  # E: Property "b" defined in "FrozenFrozen" is read-only

c = NonFrozenFrozen(1, 2)
c.a = 17  # E: Property "a" defined in "NonFrozenFrozen" is read-only
c.b = 17  # E: Property "b" defined in "NonFrozenFrozen" is read-only

[builtins fixtures/plugin_attrs.pyi]
[case testAttrsCallableAttributes]
from typing import Callable
import attr
def blah(a: int, b: int) -> bool:
    return True

@attr.s(auto_attribs=True)
class F:
    _cb: Callable[[int, int], bool] = blah
    def foo(self) -> bool:
        return self._cb(5, 6)

@attr.s
class G:
    _cb: Callable[[int, int], bool] = attr.ib(blah)
    def foo(self) -> bool:
        return self._cb(5, 6)

@attr.s(auto_attribs=True, frozen=True)
class FFrozen(F):
    def bar(self) -> bool:
        return self._cb(5, 6)
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsWithFactory]
from typing import List
import attr
def my_factory() -> int:
    return 7
@attr.s
class A:
    x: List[int] = attr.ib(factory=list)
    y: int = attr.ib(factory=my_factory)
A()
[builtins fixtures/list.pyi]

[case testAttrsFactoryAndDefault]
import attr
@attr.s
class A:
    x: int = attr.ib(factory=int, default=7)  # E: Can't pass both "default" and "factory".
[builtins fixtures/bool.pyi]

[case testAttrsFactoryBadReturn]
import attr
def my_factory() -> int:
    return 7
@attr.s
class A:
    x: int = attr.ib(factory=list)  # E: Incompatible types in assignment (expression has type "list[Never]", variable has type "int")
    y: str = attr.ib(factory=my_factory) # E: Incompatible types in assignment (expression has type "int", variable has type "str")
[builtins fixtures/list.pyi]

[case testAttrsDefaultAndInit]
import attr

@attr.s
class C:
   a = attr.ib(init=False, default=42)
   b = attr.ib()  # Ok because previous attribute is init=False
   c = attr.ib(default=44)
   d = attr.ib(init=False)  # Ok because this attribute is init=False
   e = attr.ib()  # E: Non-default attributes not allowed after default attributes.

[builtins fixtures/bool.pyi]

[case testAttrsOptionalConverter]
import attr
from attr.converters import optional
from typing import Optional

def converter(s:int) -> str:
    return 'hello'


@attr.s
class A:
    y: Optional[int] = attr.ib(converter=optional(int))
    z: Optional[str] = attr.ib(converter=optional(converter))


A(None, None)

[builtins fixtures/plugin_attrs.pyi]

[case testAttrsOptionalConverterNewPackage]
import attrs
from attrs.converters import optional
from typing import Optional

def converter(s:int) -> str:
    return 'hello'


@attrs.define
class A:
    y: Optional[int] = attrs.field(converter=optional(int))
    z: Optional[str] = attrs.field(converter=optional(converter))


A(None, None)

[builtins fixtures/plugin_attrs.pyi]


[case testAttrsTypeVarNoCollision]
from typing import TypeVar, Generic
import attr

T = TypeVar("T", bytes, str)

# Make sure the generated __le__ (and friends) don't use T for their arguments.
@attr.s(auto_attribs=True)
class A(Generic[T]):
    v: T
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsKwOnlyAttrib]
import attr
@attr.s
class A:
    a = attr.ib(kw_only=True)
A()  # E: Missing named argument "a" for "A"
A(15) # E: Too many positional arguments for "A"
A(a=15)
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsKwOnlyClass]
import attr
@attr.s(kw_only=True, auto_attribs=True)
class A:
    a: int
    b: bool
A()  # E: Missing named argument "a" for "A" # E: Missing named argument "b" for "A"
A(b=True, a=15)
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsKwOnlyClassNoInit]
import attr
@attr.s(kw_only=True)
class B:
    a = attr.ib(init=False)
    b = attr.ib()
B(b=True)
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsKwOnlyWithDefault]
import attr
@attr.s
class C:
    a = attr.ib(0)
    b = attr.ib(kw_only=True)
    c = attr.ib(16, kw_only=True)
C(b=17)
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsKwOnlyClassWithMixedDefaults]
import attr
@attr.s(kw_only=True)
class D:
    a = attr.ib(10)
    b = attr.ib()
    c = attr.ib(15)
D(b=17)
[builtins fixtures/plugin_attrs.pyi]


[case testAttrsKwOnlyClassAttributeFalse]
from attrs import define, field
@define(kw_only=True)
class A:
    a: int = field(kw_only=False)
    b: int = 1
A(0)
A(1, b=3)
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsKwOnlyClassAttributeFalseSubclass]
from attrs import define, field
@define(kw_only=True)
class A:
    a: int = field(kw_only=False)
    b: int = 1
@define(kw_only=True)
class B(A):
    c: int = field(kw_only=False)
    d: int = 3

B(0, 1)
B(0, 1, b=3, d=4)
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsKwOnlyClassAttributeFalseSubclassOnly]
from attrs import define, field
@define
class A:
    a: int
    b: int = field(kw_only=True, default=1)
@define(kw_only=True)
class B(A):
    c: int = field(kw_only=False)
    d: int = 3

B(0, 1)
B(0, 1, b=3, d=4)
[builtins fixtures/plugin_attrs.pyi]


[case testAttrsKwOnlySubclass]
import attr
@attr.s
class A2:
     a = attr.ib(default=0)
@attr.s
class B2(A2):
    b = attr.ib(kw_only=True)
B2(b=1)
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsNonKwOnlyAfterKwOnly]
import attr
@attr.s(kw_only=True)
class A:
     a = attr.ib(default=0)
@attr.s
class B(A):
    b = attr.ib()
@attr.s
class C:
    a = attr.ib(kw_only=True)
    b = attr.ib(15)

[builtins fixtures/plugin_attrs.pyi]

[case testAttrsDisallowUntypedWorksForward]
# flags: --disallow-untyped-defs
import attr
from typing import List

@attr.s
class B:
    x: C = attr.ib()

class C(List[C]):
    pass

reveal_type(B)  # N: Revealed type is "def (x: __main__.C) -> __main__.B"
[builtins fixtures/list.pyi]

[case testDisallowUntypedWorksForwardBad]
# flags: --disallow-untyped-defs
import attr

@attr.s
class B:
    x = attr.ib()  # E: Need type annotation for "x"

reveal_type(B)  # N: Revealed type is "def (x: Any) -> __main__.B"
[builtins fixtures/list.pyi]

[case testAttrsDefaultDecoratorDeferred]
defer: Yes

import attr
@attr.s
class C(object):
    x: int = attr.ib(default=1)
    y: int = attr.ib()
    @y.default
    def inc(self):
        return self.x + 1

class Yes: ...
[builtins fixtures/list.pyi]

[case testAttrsValidatorDecoratorDeferred]
defer: Yes

import attr
@attr.s
class C(object):
    x = attr.ib()
    @x.validator
    def check(self, attribute, value):
        if value > 42:
            raise ValueError("x must be smaller or equal to 42")
C(42)
C(43)

class Yes: ...
[builtins fixtures/exception.pyi]

[case testTypeInAttrUndefined]
import attr

@attr.s
class C:
    total = attr.ib(type=Bad)  # E: Name "Bad" is not defined
[builtins fixtures/bool.pyi]

[case testTypeInAttrForwardInRuntime]
import attr

@attr.s
class C:
    total = attr.ib(type=Forward)

reveal_type(C.total)  # N: Revealed type is "__main__.Forward"
C('no')  # E: Argument 1 to "C" has incompatible type "str"; expected "Forward"
class Forward: ...
[builtins fixtures/bool.pyi]

[case testDefaultInAttrForward]
import attr

@attr.s
class C:
    total = attr.ib(default=func())

def func() -> int: ...

C()
C(1)
C(1, 2)  # E: Too many arguments for "C"
[builtins fixtures/bool.pyi]

[case testTypeInAttrUndefinedFrozen]
import attr

@attr.s(frozen=True)
class C:
    total = attr.ib(type=Bad)  # E: Name "Bad" is not defined

C(0).total = 1  # E: Property "total" defined in "C" is read-only
[builtins fixtures/plugin_attrs.pyi]

[case testTypeInAttrDeferredStar]
import lib
[file lib.py]
import attr
MYPY = False
if MYPY:  # Force deferral
    from other import *

@attr.s
class C:
    total = attr.ib(type=int)

C()  # E: Missing positional argument "total" in call to "C"
C('no')  # E: Argument 1 to "C" has incompatible type "str"; expected "int"
[file other.py]
import lib
[builtins fixtures/bool.pyi]

[case testAttrsDefaultsMroOtherFile]
import a

[file a.py]
import attr
from b import A1, A2

@attr.s
class Asdf(A1, A2):  # E: Non-default attributes not allowed after default attributes.
    pass

[file b.py]
import attr

@attr.s
class A1:
    a: str = attr.ib('test')

@attr.s
class A2:
    b: int = attr.ib()

[builtins fixtures/list.pyi]

[case testAttrsInheritanceNoAnnotation]
import attr

@attr.s
class A:
    foo = attr.ib()  # type: int

x = 0
@attr.s
class B(A):
    foo = x

reveal_type(B)  # N: Revealed type is "def (foo: builtins.int) -> __main__.B"
[builtins fixtures/bool.pyi]

[case testAttrsClassHasMagicAttribute]
import attr

@attr.s
class A:
    b: int = attr.ib()
    c: str = attr.ib()

reveal_type(A.__attrs_attrs__)  # N: Revealed type is "tuple[attr.Attribute[builtins.int], attr.Attribute[builtins.str], fallback=__main__.A.____main___A_AttrsAttributes__]"
reveal_type(A.__attrs_attrs__[0])  # N: Revealed type is "attr.Attribute[builtins.int]"
reveal_type(A.__attrs_attrs__.b)  # N: Revealed type is "attr.Attribute[builtins.int]"
A.__attrs_attrs__.x  # E: "____main___A_AttrsAttributes__" has no attribute "x"

[builtins fixtures/plugin_attrs.pyi]

[case testAttrsBareClassHasMagicAttribute]
import attr

@attr.s
class A:
    b = attr.ib()
    c = attr.ib()

reveal_type(A.__attrs_attrs__)  # N: Revealed type is "tuple[attr.Attribute[Any], attr.Attribute[Any], fallback=__main__.A.____main___A_AttrsAttributes__]"
reveal_type(A.__attrs_attrs__[0])  # N: Revealed type is "attr.Attribute[Any]"
reveal_type(A.__attrs_attrs__.b)  # N: Revealed type is "attr.Attribute[Any]"
A.__attrs_attrs__.x  # E: "____main___A_AttrsAttributes__" has no attribute "x"

[builtins fixtures/plugin_attrs.pyi]

[case testAttrsNGClassHasMagicAttribute]
import attr

@attr.define
class A:
    b: int
    c: str

reveal_type(A.__attrs_attrs__)  # N: Revealed type is "tuple[attr.Attribute[builtins.int], attr.Attribute[builtins.str], fallback=__main__.A.____main___A_AttrsAttributes__]"
reveal_type(A.__attrs_attrs__[0])  # N: Revealed type is "attr.Attribute[builtins.int]"
reveal_type(A.__attrs_attrs__.b)  # N: Revealed type is "attr.Attribute[builtins.int]"
A.__attrs_attrs__.x  # E: "____main___A_AttrsAttributes__" has no attribute "x"

[builtins fixtures/plugin_attrs.pyi]

[case testAttrsMagicAttributeProtocol]
import attr
from typing import Any, Protocol, Type, ClassVar

class AttrsInstance(Protocol):
    __attrs_attrs__: ClassVar[Any]

@attr.define
class A:
    b: int
    c: str

def takes_attrs_cls(cls: Type[AttrsInstance]) -> None:
    pass

def takes_attrs_instance(inst: AttrsInstance) -> None:
    pass

takes_attrs_cls(A)
takes_attrs_instance(A(1, ""))

takes_attrs_cls(A(1, ""))  # E: Argument 1 to "takes_attrs_cls" has incompatible type "A"; expected "type[AttrsInstance]"
takes_attrs_instance(A)  # E: Argument 1 to "takes_attrs_instance" has incompatible type "type[A]"; expected "AttrsInstance" # N: ClassVar protocol member AttrsInstance.__attrs_attrs__ can never be matched by a class object
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsFields]
import attr
from attrs import fields as f  # Common usage.

@attr.define
class A:
    b: int
    c: str

reveal_type(f(A))  # N: Revealed type is "tuple[attr.Attribute[builtins.int], attr.Attribute[builtins.str], fallback=__main__.A.____main___A_AttrsAttributes__]"
reveal_type(f(A)[0])  # N: Revealed type is "attr.Attribute[builtins.int]"
reveal_type(f(A).b)  # N: Revealed type is "attr.Attribute[builtins.int]"
f(A).x  # E: "____main___A_AttrsAttributes__" has no attribute "x"

for ff in f(A):
    reveal_type(ff)  # N: Revealed type is "attr.Attribute[Any]"

[builtins fixtures/plugin_attrs.pyi]

[case testAttrsGenericFields]
from typing import TypeVar

import attr
from attrs import fields

@attr.define
class A:
    b: int
    c: str

TA = TypeVar('TA', bound=A)

def f(t: TA) -> None:
    reveal_type(fields(t))  # N: Revealed type is "tuple[attr.Attribute[builtins.int], attr.Attribute[builtins.str], fallback=__main__.A.____main___A_AttrsAttributes__]"
    reveal_type(fields(t)[0])  # N: Revealed type is "attr.Attribute[builtins.int]"
    reveal_type(fields(t).b)  # N: Revealed type is "attr.Attribute[builtins.int]"
    fields(t).x  # E: "____main___A_AttrsAttributes__" has no attribute "x"


[builtins fixtures/plugin_attrs.pyi]

[case testNonattrsFields]
from typing import Any, cast, Type
from attrs import fields, has

class A:
    b: int
    c: str

if has(A):
    fields(A)
else:
    fields(A)  # E: Argument 1 to "fields" has incompatible type "type[A]"; expected "type[AttrsInstance]"
fields(None)  # E: Argument 1 to "fields" has incompatible type "None"; expected "type[AttrsInstance]"
fields(cast(Any, 42))
fields(cast(Type[Any], 43))

[builtins fixtures/plugin_attrs.pyi]

[case testAttrsInitMethodAlwaysGenerates]
from typing import Tuple
import attr

@attr.define(init=False)
class A:
    b: int
    c: str
    def __init__(self, bc: Tuple[int, str]) -> None:
        b, c = bc
        self.__attrs_init__(b, c)

reveal_type(A)  # N: Revealed type is "def (bc: tuple[builtins.int, builtins.str]) -> __main__.A"
reveal_type(A.__init__)  # N: Revealed type is "def (self: __main__.A, bc: tuple[builtins.int, builtins.str])"
reveal_type(A.__attrs_init__)  # N: Revealed type is "def (self: __main__.A, b: builtins.int, c: builtins.str)"

[builtins fixtures/plugin_attrs.pyi]

[case testAttrsClassWithSlots]
import attr

@attr.define
class Define:
    b: int = attr.ib()

    def __attrs_post_init__(self) -> None:
        self.b = 1
        self.c = 2  # E: Trying to assign name "c" that is not in "__slots__" of type "__main__.Define"


@attr.define(slots=False)
class DefineSlotsFalse:
    b: int = attr.ib()

    def __attrs_post_init__(self) -> None:
        self.b = 1
        self.c = 2


@attr.s(slots=True)
class A:
    b: int = attr.ib()

    def __attrs_post_init__(self) -> None:
        self.b = 1
        self.c = 2  # E: Trying to assign name "c" that is not in "__slots__" of type "__main__.A"

@attr.dataclass(slots=True)
class B:
    __slots__ = ()  # would be replaced
    b: int

    def __attrs_post_init__(self) -> None:
        self.b = 1
        self.c = 2  # E: Trying to assign name "c" that is not in "__slots__" of type "__main__.B"

@attr.dataclass(slots=False)
class C:
    __slots__ = ()  # would not be replaced
    b: int

    def __attrs_post_init__(self) -> None:
        self.b = 1  # E: Trying to assign name "b" that is not in "__slots__" of type "__main__.C"
        self.c = 2  # E: Trying to assign name "c" that is not in "__slots__" of type "__main__.C"
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsClassWithSlotsDerivedFromNonSlots]
import attrs

class A:
    pass

@attrs.define(slots=True)
class B(A):
    x: int

    def __attrs_post_init__(self) -> None:
        self.y = 42

[builtins fixtures/plugin_attrs.pyi]

[case testRuntimeSlotsAttr]
from attr import dataclass

@dataclass(slots=True)
class Some:
    x: int
    y: str
    z: bool

reveal_type(Some.__slots__)  # N: Revealed type is "tuple[builtins.str, builtins.str, builtins.str]"

@dataclass(slots=True)
class Other:
    x: int
    y: str

reveal_type(Other.__slots__)  # N: Revealed type is "tuple[builtins.str, builtins.str]"


@dataclass
class NoSlots:
    x: int
    y: str

NoSlots.__slots__  # E: "type[NoSlots]" has no attribute "__slots__"
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsWithMatchArgs]
import attr

@attr.s(match_args=True, auto_attribs=True)
class ToMatch:
    x: int
    y: int
    # Not included:
    z: int = attr.field(kw_only=True)
    i: int = attr.field(init=False)

reveal_type(ToMatch(x=1, y=2, z=3).__match_args__)  # N: Revealed type is "tuple[Literal['x']?, Literal['y']?]"
reveal_type(ToMatch(1, 2, z=3).__match_args__)      # N: Revealed type is "tuple[Literal['x']?, Literal['y']?]"
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsWithMatchArgsDefaultCase]
import attr

@attr.s(auto_attribs=True)
class ToMatch1:
    x: int
    y: int

t1: ToMatch1
reveal_type(t1.__match_args__)  # N: Revealed type is "tuple[Literal['x']?, Literal['y']?]"

@attr.define
class ToMatch2:
    x: int
    y: int

t2: ToMatch2
reveal_type(t2.__match_args__)  # N: Revealed type is "tuple[Literal['x']?, Literal['y']?]"
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsWithMatchArgsOverrideExisting]
import attr
from typing import Final

@attr.s(match_args=True, auto_attribs=True)
class ToMatch:
    __match_args__: Final = ('a', 'b')
    x: int
    y: int

# It works the same way runtime does:
reveal_type(ToMatch(x=1, y=2).__match_args__)  # N: Revealed type is "tuple[Literal['a']?, Literal['b']?]"

@attr.s(auto_attribs=True)
class WithoutMatch:
    __match_args__: Final = ('a', 'b')
    x: int
    y: int

reveal_type(WithoutMatch(x=1, y=2).__match_args__)  # N: Revealed type is "tuple[Literal['a']?, Literal['b']?]"
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsMultipleInheritance]
import attr

@attr.s
class A:
    x = attr.ib(type=int)

@attr.s
class B:
    y = attr.ib(type=int)

class AB(A, B):
    pass
[builtins fixtures/plugin_attrs.pyi]
[typing fixtures/typing-full.pyi]

[case testAttrsForwardReferenceInTypeVarBound]
from typing import TypeVar, Generic
import attr

T = TypeVar("T", bound="C")

@attr.define
class D(Generic[T]):
    x: int

class C:
    pass
[builtins fixtures/plugin_attrs.pyi]

[case testComplexTypeInAttrIb]
import a

[file a.py]
import attr
import b
from typing import Callable

@attr.s
class C:
    a = attr.ib(type=Lst[int])  # E: Name "Lst" is not defined
    # Note that for this test, the 'Value of type "int" is not indexable' errors are silly,
    # and a consequence of Callable etc. being set to an int in the test stub.
    b = attr.ib(type=Callable[[], C])  # E: Value of type "int" is not indexable
[file b.py]
import attr
import a
from typing import List as Lst, Optional

@attr.s
class D:
    a = attr.ib(type=Lst[int])
    b = attr.ib(type=Optional[int])  # E: Value of type "int" is not indexable
[builtins fixtures/list.pyi]

[case testAttrsGenericInheritanceSpecialCase1]
import attr
from typing import Generic, TypeVar, List

T = TypeVar("T")

@attr.define
class Parent(Generic[T]):
    x: List[T]

@attr.define
class Child1(Parent["Child2"]): ...

@attr.define
class Child2(Parent["Child1"]): ...

def f(c: Child2) -> None:
    reveal_type(Child1([c]).x)  # N: Revealed type is "builtins.list[__main__.Child2]"

def g(c: Child1) -> None:
    reveal_type(Child2([c]).x)  # N: Revealed type is "builtins.list[__main__.Child1]"
[builtins fixtures/list.pyi]

[case testAttrsGenericInheritanceSpecialCase2]
import attr
from typing import Generic, TypeVar

T = TypeVar("T")

# A subclass might be analyzed before base in import cycles.  They are
# defined here in reversed order to simulate this.

@attr.define
class Child1(Parent["Child2"]):
    x: int

@attr.define
class Child2(Parent["Child1"]):
    y: int

@attr.define
class Parent(Generic[T]):
    key: str

Child1(x=1, key='')
Child2(y=1, key='')
[builtins fixtures/list.pyi]

[case testAttrsUnsupportedConverterWithDisallowUntypedDefs]
# flags: --disallow-untyped-defs
import attr
from typing import Mapping, Any, Union

def default_if_none(factory: Any) -> Any: pass

@attr.s(slots=True, frozen=True)
class C:
    name: Union[str, None] = attr.ib(default=None)
    options: Mapping[str, Mapping[str, Any]] = attr.ib(
        default=None, converter=default_if_none(factory=dict) \
        # E: Unsupported converter, only named functions, types and lambdas are currently supported
    )
[builtins fixtures/plugin_attrs.pyi]

[case testAttrsUnannotatedConverter]
import attr

def foo(value):
    return value.split()

@attr.s
class Bar:
    field = attr.ib(default=None, converter=foo)

reveal_type(Bar)  # N: Revealed type is "def (field: Any =) -> __main__.Bar"
bar = Bar("Hello")
reveal_type(bar.field)  # N: Revealed type is "Any"

[builtins fixtures/tuple.pyi]

[case testAttrsLambdaConverter]
import attr

@attr.s
class Bar:
    name: str = attr.ib(converter=lambda s: s.lower())

reveal_type(Bar)  # N: Revealed type is "def (name: Any) -> __main__.Bar"
bar = Bar("Hello")
reveal_type(bar.name)  # N: Revealed type is "builtins.str"

[builtins fixtures/tuple.pyi]

[case testAttrsNestedClass]
from typing import List
import attr

@attr.s
class C:
    @attr.s
    class D:
        pass
    x = attr.ib(type=List[D])

c = C(x=[C.D()])
reveal_type(c.x)  # N: Revealed type is "builtins.list[__main__.C.D]"
[builtins fixtures/list.pyi]

[case testRedefinitionInFrozenClassNoCrash]
import attr

@attr.s
class MyData:
    is_foo: bool = attr.ib()

    @staticmethod  # E: Name "is_foo" already defined on line 5
    def is_foo(string: str) -> bool: ...
[builtins fixtures/classmethod.pyi]

[case testOverrideWithPropertyInFrozenClassNoCrash]
from attrs import frozen

@frozen(kw_only=True)
class Base:
    name: str

@frozen(kw_only=True)
class Sub(Base):
    first_name: str
    last_name: str

    @property
    def name(self) -> str: ...
[builtins fixtures/plugin_attrs.pyi]

[case testOverrideWithPropertyInFrozenClassChecked]
from attrs import frozen

@frozen(kw_only=True)
class Base:
    name: str

@frozen(kw_only=True)
class Sub(Base):
    first_name: str
    last_name: str

    @property
    def name(self) -> int: ...  # E: Signature of "name" incompatible with supertype "Base" \
                                # N:      Superclass: \
                                # N:          str \
                                # N:      Subclass: \
                                # N:          int

# This matches runtime semantics
reveal_type(Sub)  # N: Revealed type is "def (*, name: builtins.str, first_name: builtins.str, last_name: builtins.str) -> __main__.Sub"
[builtins fixtures/plugin_attrs.pyi]

[case testFinalInstanceAttribute]
from attrs import define
from typing import Final

@define
class C:
    a: Final[int]

reveal_type(C) # N: Revealed type is "def (a: builtins.int) -> __main__.C"

C(1).a = 2 # E: Cannot assign to final attribute "a"

[builtins fixtures/property.pyi]

[case testFinalInstanceAttributeInheritance]
from attrs import define
from typing import Final

@define
class C:
    a: Final[int]

@define
class D(C):
    b: Final[str]

reveal_type(D) # N: Revealed type is "def (a: builtins.int, b: builtins.str) -> __main__.D"

D(1, "").a = 2 # E: Cannot assign to final attribute "a"
D(1, "").b = "2" # E: Cannot assign to final attribute "b"

[builtins fixtures/property.pyi]

[case testEvolve]
import attr

class Base:
    pass

class Derived(Base):
    pass

class Other:
    pass

@attr.s(auto_attribs=True)
class C:
    name: str
    b: Base

c = C(name='foo', b=Derived())
c = attr.evolve(c)
c = attr.evolve(c, name='foo')
c = attr.evolve(c, 'foo')  # E: Too many positional arguments for "evolve" of "C"
c = attr.evolve(c, b=Derived())
c = attr.evolve(c, b=Base())
c = attr.evolve(c, b=Other())  # E: Argument "b" to "evolve" of "C" has incompatible type "Other"; expected "Base"
c = attr.evolve(c, name=42)  # E: Argument "name" to "evolve" of "C" has incompatible type "int"; expected "str"
c = attr.evolve(c, foobar=42)  # E: Unexpected keyword argument "foobar" for "evolve" of "C"

# test passing instance as 'inst' kw
c = attr.evolve(inst=c, name='foo')
c = attr.evolve(not_inst=c, name='foo')  # E: Missing positional argument "inst" in call to "evolve"

# test determining type of first argument's expression from something that's not NameExpr
def f() -> C:
    return c

c = attr.evolve(f(), name='foo')

[builtins fixtures/plugin_attrs.pyi]

[case testEvolveFromNonAttrs]
import attr

attr.evolve(42, name='foo')  # E: Argument 1 to "evolve" has incompatible type "int"; expected an attrs class
attr.evolve(None, name='foo')  # E: Argument 1 to "evolve" has incompatible type "None"; expected an attrs class
[case testEvolveFromAny]
from typing import Any
import attr

any: Any = 42
ret = attr.evolve(any, name='foo')
reveal_type(ret)  # N: Revealed type is "Any"

[typing fixtures/typing-medium.pyi]

[case testEvolveGeneric]
import attrs
from typing import Generic, TypeVar

T = TypeVar('T')

@attrs.define
class A(Generic[T]):
    x: T


a = A(x=42)
reveal_type(a)  # N: Revealed type is "__main__.A[builtins.int]"
a2 = attrs.evolve(a, x=42)
reveal_type(a2)  # N: Revealed type is "__main__.A[builtins.int]"
a2 = attrs.evolve(a, x='42')  # E: Argument "x" to "evolve" of "A[int]" has incompatible type "str"; expected "int"
reveal_type(a2)  # N: Revealed type is "__main__.A[builtins.int]"

[builtins fixtures/plugin_attrs.pyi]

[case testEvolveUnion]
from typing import Generic, TypeVar
import attrs

T = TypeVar('T')


@attrs.define
class A(Generic[T]):
    x: T  # exercises meet(T=int, int) = int
    y: bool  # exercises meet(bool, int) = bool
    z: str  # exercises meet(str, bytes) = Never
    w: dict  # exercises meet(dict, Never) = Never


@attrs.define
class B:
    x: int
    y: bool
    z: bytes


a_or_b: A[int] | B
a2 = attrs.evolve(a_or_b, x=42, y=True)
a2 = attrs.evolve(a_or_b, x=42, y=True, z='42')  # E: Argument "z" to "evolve" of "A[int] | B" has incompatible type "str"; expected "Never"
a2 = attrs.evolve(a_or_b, x=42, y=True, w={})  # E: Argument "w" to "evolve" of "A[int] | B" has incompatible type "dict[Never, Never]"; expected "Never"

[builtins fixtures/plugin_attrs.pyi]

[case testEvolveUnionOfTypeVar]
import attrs
from typing import TypeVar

@attrs.define
class A:
    x: int
    y: int
    z: str
    w: dict


class B:
    pass

TA = TypeVar('TA', bound=A)
TB = TypeVar('TB', bound=B)

def f(b_or_t: TA | TB | int) -> None:
    a2 = attrs.evolve(b_or_t)  # E: Argument 1 to "evolve" has type "TA | TB | int" whose item "TB" is not bound to an attrs class \
                               # E: Argument 1 to "evolve" has incompatible type "TA | TB | int" whose item "int" is not an attrs class


[builtins fixtures/plugin_attrs.pyi]

[case testEvolveTypeVarBound]
import attrs
from typing import TypeVar

@attrs.define
class A:
    x: int

@attrs.define
class B(A):
    pass

TA = TypeVar('TA', bound=A)

def f(t: TA) -> TA:
    t2 = attrs.evolve(t, x=42)
    reveal_type(t2)  # N: Revealed type is "TA`-1"
    t3 = attrs.evolve(t, x='42')  # E: Argument "x" to "evolve" of "TA" has incompatible type "str"; expected "int"
    return t2

f(A(x=42))
f(B(x=42))

[builtins fixtures/plugin_attrs.pyi]

[case testEvolveTypeVarBoundNonAttrs]
import attrs
from typing import Union, TypeVar

TInt = TypeVar('TInt', bound=int)
TAny = TypeVar('TAny')
TNone = TypeVar('TNone', bound=None)
TUnion = TypeVar('TUnion', bound=Union[str, int])

def f(t: TInt) -> None:
    _ = attrs.evolve(t, x=42)  # E: Argument 1 to "evolve" has a variable type "TInt" not bound to an attrs class

def g(t: TAny) -> None:
    _ = attrs.evolve(t, x=42)  # E: Argument 1 to "evolve" has a variable type "TAny" not bound to an attrs class

def h(t: TNone) -> None:
    _ = attrs.evolve(t, x=42)  # E: Argument 1 to "evolve" has a variable type "TNone" not bound to an attrs class

def x(t: TUnion) -> None:
    _ = attrs.evolve(t, x=42)  # E: Argument 1 to "evolve" has incompatible type "TUnion" whose item "str" is not an attrs class \
                               # E: Argument 1 to "evolve" has incompatible type "TUnion" whose item "int" is not an attrs class

[builtins fixtures/plugin_attrs.pyi]

[case testEvolveTypeVarConstrained]
import attrs
from typing import TypeVar

@attrs.define
class A:
    x: int

@attrs.define
class B:
    x: str  # conflicting with A.x

T = TypeVar('T', A, B)

def f(t: T) -> T:
    t2 = attrs.evolve(t, x=42)  # E: Argument "x" to "evolve" of "B" has incompatible type "int"; expected "str"
    reveal_type(t2)  # N: Revealed type is "__main__.A"  # N: Revealed type is "__main__.B"
    t2 = attrs.evolve(t, x='42')  # E: Argument "x" to "evolve" of "A" has incompatible type "str"; expected "int"
    return t2

f(A(x=42))
f(B(x='42'))

[builtins fixtures/plugin_attrs.pyi]

[case testEvolveVariants]
from typing import Any
import attr
import attrs


@attr.s(auto_attribs=True)
class C:
    name: str

c = C(name='foo')

c = attr.assoc(c, name='test')
c = attr.assoc(c, name=42)  # E: Argument "name" to "assoc" of "C" has incompatible type "int"; expected "str"

c = attrs.evolve(c, name='test')
c = attrs.evolve(c, name=42)  # E: Argument "name" to "evolve" of "C" has incompatible type "int"; expected "str"

c = attrs.assoc(c, name='test')
c = attrs.assoc(c, name=42)  # E: Argument "name" to "assoc" of "C" has incompatible type "int"; expected "str"

[builtins fixtures/plugin_attrs.pyi]
[typing fixtures/typing-medium.pyi]

[case testFrozenInheritFromGeneric]
from typing import Generic, TypeVar
from attrs import field, frozen

T = TypeVar('T')

def f(s: str) -> int:
    ...

@frozen
class A(Generic[T]):
    x: T
    y: int = field(converter=f)

@frozen
class B(A[int]):
    pass

b = B(42, 'spam')
reveal_type(b.x)  # N: Revealed type is "builtins.int"
reveal_type(b.y)  # N: Revealed type is "builtins.int"

[builtins fixtures/plugin_attrs.pyi]

[case testDefaultHashability]
from attrs import define

@define
class A:
    a: int

reveal_type(A.__hash__)  # N: Revealed type is "None"

[builtins fixtures/plugin_attrs.pyi]

[case testFrozenHashability]
from attrs import frozen

@frozen
class A:
    a: int

reveal_type(A.__hash__)  # N: Revealed type is "def (self: builtins.object) -> builtins.int"

[builtins fixtures/plugin_attrs.pyi]

[case testManualHashHashability]
from attrs import define

@define(hash=True)
class A:
    a: int

reveal_type(A.__hash__)  # N: Revealed type is "def (self: builtins.object) -> builtins.int"

[builtins fixtures/plugin_attrs.pyi]

[case testManualUnsafeHashHashability]
from attrs import define

@define(unsafe_hash=True)
class A:
    a: int

reveal_type(A.__hash__)  # N: Revealed type is "def (self: builtins.object) -> builtins.int"

[builtins fixtures/plugin_attrs.pyi]

[case testSubclassingHashability]
from attrs import define

@define(unsafe_hash=True)
class A:
    a: int

@define
class B(A):
    pass

reveal_type(B.__hash__)  # N: Revealed type is "None"

[builtins fixtures/plugin_attrs.pyi]

[case testManualOwnHashability]
from attrs import define, frozen

@define
class A:
    a: int
    def __hash__(self) -> int:
        ...

reveal_type(A.__hash__)  # N: Revealed type is "def (self: __main__.A) -> builtins.int"

[builtins fixtures/plugin_attrs.pyi]

[case testSubclassDefaultLosesHashability]
from attrs import define, frozen

@define
class A:
    a: int
    def __hash__(self) -> int:
        ...

@define
class B(A):
    pass

reveal_type(B.__hash__)  # N: Revealed type is "None"

[builtins fixtures/plugin_attrs.pyi]

[case testSubclassEqFalseKeepsHashability]
from attrs import define, frozen

@define
class A:
    a: int
    def __hash__(self) -> int:
        ...

@define(eq=False)
class B(A):
    pass

reveal_type(B.__hash__)  # N: Revealed type is "def (self: __main__.A) -> builtins.int"

[builtins fixtures/plugin_attrs.pyi]

[case testSubclassingFrozenHashability]
from attrs import define, frozen

@define
class A:
    a: int

@frozen
class B(A):
    pass

reveal_type(B.__hash__)  # N: Revealed type is "def (self: builtins.object) -> builtins.int"

[builtins fixtures/plugin_attrs.pyi]

[case testSubclassingFrozenHashOffHashability]
from attrs import define, frozen

@define
class A:
    a: int
    def __hash__(self) -> int:
        ...

@frozen(unsafe_hash=False)
class B(A):
    pass

reveal_type(B.__hash__)  # N: Revealed type is "None"

[builtins fixtures/plugin_attrs.pyi]

[case testUnsafeHashPrecedence]
from attrs import define, frozen

@define(unsafe_hash=True, hash=False)
class A:
    pass
reveal_type(A.__hash__)  # N: Revealed type is "def (self: builtins.object) -> builtins.int"

@define(unsafe_hash=False, hash=True)
class B:
    pass
reveal_type(B.__hash__)  # N: Revealed type is "None"

[builtins fixtures/plugin_attrs.pyi]

[case testAttrsStrictOptionalSetProperly]
from typing import Generic, Optional, TypeVar

import attr

T = TypeVar("T")

@attr.mutable()
class Parent(Generic[T]):
    run_type: Optional[int] = None

@attr.mutable()
class Child(Parent[float]):
    pass

Parent(run_type = None)
c = Child(run_type = None)
reveal_type(c.run_type)  # N: Revealed type is "builtins.int | None"
[builtins fixtures/plugin_attrs.pyi]