"""

Tests the dataclass_transform mechanism when it is applied to a base class.

"""

# Specification: https://typing.readthedocs.io/en/latest/spec/dataclasses.html#the-dataclass-transform-decorator

from typing import Any, Generic, TypeVar, dataclass_transform

T = TypeVar("T")

class ModelField:

def __init__(self, *, init: bool = True, default: Any | None = None) -> None:

...

def model_field(

*, init: bool = True, default: Any | None = None, alias: str | None = None

) -> Any:

raise NotImplementedError

@dataclass_transform(

kw_only_default=True,

field_specifiers=(ModelField, model_field),

)

class ModelBase:

not_a_field: str

def __init_subclass__(

cls,

*,

frozen: bool = False,

kw_only: bool = True,

order: bool = True,

) -> None:

...

def __init__(self, not_a_field: str) -> None:

self.not_a_field = not_a_field

class Customer1(ModelBase, frozen=True):

id: int = model_field()

name: str = model_field()

name2: str = model_field(alias="other_name", default="None")

# This should generate an error because a non-frozen dataclass cannot

# derive from a frozen one.

class Customer1Subclass(Customer1): # E

salary: float = model_field()

class Customer2(ModelBase, order=True):

id: int

name: str = model_field(default="None")

c1_1 = Customer1(id=3, name="Sue", other_name="Susan")

# This should generate an error because the class is frozen.

c1_1.id = 4 # E

# This should generate an error because the class is kw_only.

c1_2 = Customer1(3, "Sue") # E

c1_3 = Customer1(id=3, name="John")

# This should generate an error because comparison methods are

# not synthesized.

v1 = c1_1 < c1_2 # E

c2_1 = Customer2(id=0, name="John")

c2_2 = Customer2(id=1)

v2 = c2_1 < c2_2

# This should generate an error because Customer2 supports

# keyword-only parameters for its constructor.

c2_3 = Customer2(0, "John") # E

@dataclass_transform(

kw_only_default=True,

field_specifiers=(ModelField, model_field),

)

class GenericModelBase(Generic[T]):

not_a_field: T

def __init_subclass__(

cls,

*,

frozen: bool = False,

kw_only: bool = True,

order: bool = True,

) -> None:

...

class GenericCustomer(GenericModelBase[int]):

id: int = model_field()

gc_1 = GenericCustomer(id=3)

@dataclass_transform(frozen_default=True)

class ModelBaseFrozen:

not_a_field: str

class Customer3(ModelBaseFrozen):

id: int

name: str

c3_1 = Customer3(id=2, name="hi")

# This should generate an error because Customer3 is frozen.

c3_1.id = 4 # E