test_models.py

import json
from typing import Any, Dict, List, Union, Optional, cast
from datetime import datetime, timezone
from typing_extensions import Literal, Annotated

import pytest
import pydantic
from pydantic import Field

from openai._utils import PropertyInfo
from openai._compat import PYDANTIC_V2, parse_obj, model_dump, model_json
from openai._models import BaseModel, construct_type


class BasicModel(BaseModel):
    foo: str


@pytest.mark.parametrize("value", ["hello", 1], ids=["correct type", "mismatched"])
def test_basic(value: object) -> None:
    m = BasicModel.construct(foo=value)
    assert m.foo == value


def test_directly_nested_model() -> None:
    class NestedModel(BaseModel):
        nested: BasicModel

    m = NestedModel.construct(nested={"foo": "Foo!"})
    assert m.nested.foo == "Foo!"

    # mismatched types
    m = NestedModel.construct(nested="hello!")
    assert cast(Any, m.nested) == "hello!"


def test_optional_nested_model() -> None:
    class NestedModel(BaseModel):
        nested: Optional[BasicModel]

    m1 = NestedModel.construct(nested=None)
    assert m1.nested is None

    m2 = NestedModel.construct(nested={"foo": "bar"})
    assert m2.nested is not None
    assert m2.nested.foo == "bar"

    # mismatched types
    m3 = NestedModel.construct(nested={"foo"})
    assert isinstance(cast(Any, m3.nested), set)
    assert cast(Any, m3.nested) == {"foo"}


def test_list_nested_model() -> None:
    class NestedModel(BaseModel):
        nested: List[BasicModel]

    m = NestedModel.construct(nested=[{"foo": "bar"}, {"foo": "2"}])
    assert m.nested is not None
    assert isinstance(m.nested, list)
    assert len(m.nested) == 2
    assert m.nested[0].foo == "bar"
    assert m.nested[1].foo == "2"

    # mismatched types
    m = NestedModel.construct(nested=True)
    assert cast(Any, m.nested) is True

    m = NestedModel.construct(nested=[False])
    assert cast(Any, m.nested) == [False]


def test_optional_list_nested_model() -> None:
    class NestedModel(BaseModel):
        nested: Optional[List[BasicModel]]

    m1 = NestedModel.construct(nested=[{"foo": "bar"}, {"foo": "2"}])
    assert m1.nested is not None
    assert isinstance(m1.nested, list)
    assert len(m1.nested) == 2
    assert m1.nested[0].foo == "bar"
    assert m1.nested[1].foo == "2"

    m2 = NestedModel.construct(nested=None)
    assert m2.nested is None

    # mismatched types
    m3 = NestedModel.construct(nested={1})
    assert cast(Any, m3.nested) == {1}

    m4 = NestedModel.construct(nested=[False])
    assert cast(Any, m4.nested) == [False]


def test_list_optional_items_nested_model() -> None:
    class NestedModel(BaseModel):
        nested: List[Optional[BasicModel]]

    m = NestedModel.construct(nested=[None, {"foo": "bar"}])
    assert m.nested is not None
    assert isinstance(m.nested, list)
    assert len(m.nested) == 2
    assert m.nested[0] is None
    assert m.nested[1] is not None
    assert m.nested[1].foo == "bar"

    # mismatched types
    m3 = NestedModel.construct(nested="foo")
    assert cast(Any, m3.nested) == "foo"

    m4 = NestedModel.construct(nested=[False])
    assert cast(Any, m4.nested) == [False]


def test_list_mismatched_type() -> None:
    class NestedModel(BaseModel):
        nested: List[str]

    m = NestedModel.construct(nested=False)
    assert cast(Any, m.nested) is False


def test_raw_dictionary() -> None:
    class NestedModel(BaseModel):
        nested: Dict[str, str]

    m = NestedModel.construct(nested={"hello": "world"})
    assert m.nested == {"hello": "world"}

    # mismatched types
    m = NestedModel.construct(nested=False)
    assert cast(Any, m.nested) is False


def test_nested_dictionary_model() -> None:
    class NestedModel(BaseModel):
        nested: Dict[str, BasicModel]

    m = NestedModel.construct(nested={"hello": {"foo": "bar"}})
    assert isinstance(m.nested, dict)
    assert m.nested["hello"].foo == "bar"

    # mismatched types
    m = NestedModel.construct(nested={"hello": False})
    assert cast(Any, m.nested["hello"]) is False


def test_unknown_fields() -> None:
    m1 = BasicModel.construct(foo="foo", unknown=1)
    assert m1.foo == "foo"
    assert cast(Any, m1).unknown == 1

    m2 = BasicModel.construct(foo="foo", unknown={"foo_bar": True})
    assert m2.foo == "foo"
    assert cast(Any, m2).unknown == {"foo_bar": True}

    assert model_dump(m2) == {"foo": "foo", "unknown": {"foo_bar": True}}


def test_strict_validation_unknown_fields() -> None:
    class Model(BaseModel):
        foo: str

    model = parse_obj(Model, dict(foo="hello!", user="Robert"))
    assert model.foo == "hello!"
    assert cast(Any, model).user == "Robert"

    assert model_dump(model) == {"foo": "hello!", "user": "Robert"}


def test_aliases() -> None:
    class Model(BaseModel):
        my_field: int = Field(alias="myField")

    m = Model.construct(myField=1)
    assert m.my_field == 1

    # mismatched types
    m = Model.construct(myField={"hello": False})
    assert cast(Any, m.my_field) == {"hello": False}


def test_repr() -> None:
    model = BasicModel(foo="bar")
    assert str(model) == "BasicModel(foo='bar')"
    assert repr(model) == "BasicModel(foo='bar')"


def test_repr_nested_model() -> None:
    class Child(BaseModel):
        name: str
        age: int

    class Parent(BaseModel):
        name: str
        child: Child

    model = Parent(name="Robert", child=Child(name="Foo", age=5))
    assert str(model) == "Parent(name='Robert', child=Child(name='Foo', age=5))"
    assert repr(model) == "Parent(name='Robert', child=Child(name='Foo', age=5))"


def test_optional_list() -> None:
    class Submodel(BaseModel):
        name: str

    class Model(BaseModel):
        items: Optional[List[Submodel]]

    m = Model.construct(items=None)
    assert m.items is None

    m = Model.construct(items=[])
    assert m.items == []

    m = Model.construct(items=[{"name": "Robert"}])
    assert m.items is not None
    assert len(m.items) == 1
    assert m.items[0].name == "Robert"


def test_nested_union_of_models() -> None:
    class Submodel1(BaseModel):
        bar: bool

    class Submodel2(BaseModel):
        thing: str

    class Model(BaseModel):
        foo: Union[Submodel1, Submodel2]

    m = Model.construct(foo={"thing": "hello"})
    assert isinstance(m.foo, Submodel2)
    assert m.foo.thing == "hello"


def test_nested_union_of_mixed_types() -> None:
    class Submodel1(BaseModel):
        bar: bool

    class Model(BaseModel):
        foo: Union[Submodel1, Literal[True], Literal["CARD_HOLDER"]]

    m = Model.construct(foo=True)
    assert m.foo is True

    m = Model.construct(foo="CARD_HOLDER")
    assert m.foo is "CARD_HOLDER"

    m = Model.construct(foo={"bar": False})
    assert isinstance(m.foo, Submodel1)
    assert m.foo.bar is False


def test_nested_union_multiple_variants() -> None:
    class Submodel1(BaseModel):
        bar: bool

    class Submodel2(BaseModel):
        thing: str

    class Submodel3(BaseModel):
        foo: int

    class Model(BaseModel):
        foo: Union[Submodel1, Submodel2, None, Submodel3]

    m = Model.construct(foo={"thing": "hello"})
    assert isinstance(m.foo, Submodel2)
    assert m.foo.thing == "hello"

    m = Model.construct(foo=None)
    assert m.foo is None

    m = Model.construct()
    assert m.foo is None

    m = Model.construct(foo={"foo": "1"})
    assert isinstance(m.foo, Submodel3)
    assert m.foo.foo == 1


def test_nested_union_invalid_data() -> None:
    class Submodel1(BaseModel):
        level: int

    class Submodel2(BaseModel):
        name: str

    class Model(BaseModel):
        foo: Union[Submodel1, Submodel2]

    m = Model.construct(foo=True)
    assert cast(bool, m.foo) is True

    m = Model.construct(foo={"name": 3})
    if PYDANTIC_V2:
        assert isinstance(m.foo, Submodel1)
        assert m.foo.name == 3  # type: ignore
    else:
        assert isinstance(m.foo, Submodel2)
        assert m.foo.name == "3"


def test_list_of_unions() -> None:
    class Submodel1(BaseModel):
        level: int

    class Submodel2(BaseModel):
        name: str

    class Model(BaseModel):
        items: List[Union[Submodel1, Submodel2]]

    m = Model.construct(items=[{"level": 1}, {"name": "Robert"}])
    assert len(m.items) == 2
    assert isinstance(m.items[0], Submodel1)
    assert m.items[0].level == 1
    assert isinstance(m.items[1], Submodel2)
    assert m.items[1].name == "Robert"

    m = Model.construct(items=[{"level": -1}, 156])
    assert len(m.items) == 2
    assert isinstance(m.items[0], Submodel1)
    assert m.items[0].level == -1
    assert cast(Any, m.items[1]) == 156


def test_union_of_lists() -> None:
    class SubModel1(BaseModel):
        level: int

    class SubModel2(BaseModel):
        name: str

    class Model(BaseModel):
        items: Union[List[SubModel1], List[SubModel2]]

    # with one valid entry
    m = Model.construct(items=[{"name": "Robert"}])
    assert len(m.items) == 1
    assert isinstance(m.items[0], SubModel2)
    assert m.items[0].name == "Robert"

    # with two entries pointing to different types
    m = Model.construct(items=[{"level": 1}, {"name": "Robert"}])
    assert len(m.items) == 2
    assert isinstance(m.items[0], SubModel1)
    assert m.items[0].level == 1
    assert isinstance(m.items[1], SubModel1)
    assert cast(Any, m.items[1]).name == "Robert"

    # with two entries pointing to *completely* different types
    m = Model.construct(items=[{"level": -1}, 156])
    assert len(m.items) == 2
    assert isinstance(m.items[0], SubModel1)
    assert m.items[0].level == -1
    assert cast(Any, m.items[1]) == 156


def test_dict_of_union() -> None:
    class SubModel1(BaseModel):
        name: str

    class SubModel2(BaseModel):
        foo: str

    class Model(BaseModel):
        data: Dict[str, Union[SubModel1, SubModel2]]

    m = Model.construct(data={"hello": {"name": "there"}, "foo": {"foo": "bar"}})
    assert len(list(m.data.keys())) == 2
    assert isinstance(m.data["hello"], SubModel1)
    assert m.data["hello"].name == "there"
    assert isinstance(m.data["foo"], SubModel2)
    assert m.data["foo"].foo == "bar"

    # TODO: test mismatched type


def test_double_nested_union() -> None:
    class SubModel1(BaseModel):
        name: str

    class SubModel2(BaseModel):
        bar: str

    class Model(BaseModel):
        data: Dict[str, List[Union[SubModel1, SubModel2]]]

    m = Model.construct(data={"foo": [{"bar": "baz"}, {"name": "Robert"}]})
    assert len(m.data["foo"]) == 2

    entry1 = m.data["foo"][0]
    assert isinstance(entry1, SubModel2)
    assert entry1.bar == "baz"

    entry2 = m.data["foo"][1]
    assert isinstance(entry2, SubModel1)
    assert entry2.name == "Robert"

    # TODO: test mismatched type


def test_union_of_dict() -> None:
    class SubModel1(BaseModel):
        name: str

    class SubModel2(BaseModel):
        foo: str

    class Model(BaseModel):
        data: Union[Dict[str, SubModel1], Dict[str, SubModel2]]

    m = Model.construct(data={"hello": {"name": "there"}, "foo": {"foo": "bar"}})
    assert len(list(m.data.keys())) == 2
    assert isinstance(m.data["hello"], SubModel1)
    assert m.data["hello"].name == "there"
    assert isinstance(m.data["foo"], SubModel1)
    assert cast(Any, m.data["foo"]).foo == "bar"


def test_iso8601_datetime() -> None:
    class Model(BaseModel):
        created_at: datetime

    expected = datetime(2019, 12, 27, 18, 11, 19, 117000, tzinfo=timezone.utc)

    if PYDANTIC_V2:
        expected_json = '{"created_at":"2019-12-27T18:11:19.117000Z"}'
    else:
        expected_json = '{"created_at": "2019-12-27T18:11:19.117000+00:00"}'

    model = Model.construct(created_at="2019-12-27T18:11:19.117Z")
    assert model.created_at == expected
    assert model_json(model) == expected_json

    model = parse_obj(Model, dict(created_at="2019-12-27T18:11:19.117Z"))
    assert model.created_at == expected
    assert model_json(model) == expected_json


def test_does_not_coerce_int() -> None:
    class Model(BaseModel):
        bar: int

    assert Model.construct(bar=1).bar == 1
    assert Model.construct(bar=10.9).bar == 10.9
    assert Model.construct(bar="19").bar == "19"  # type: ignore[comparison-overlap]
    assert Model.construct(bar=False).bar is False


def test_int_to_float_safe_conversion() -> None:
    class Model(BaseModel):
        float_field: float

    m = Model.construct(float_field=10)
    assert m.float_field == 10.0
    assert isinstance(m.float_field, float)

    m = Model.construct(float_field=10.12)
    assert m.float_field == 10.12
    assert isinstance(m.float_field, float)

    # number too big
    m = Model.construct(float_field=2**53 + 1)
    assert m.float_field == 2**53 + 1
    assert isinstance(m.float_field, int)


def test_deprecated_alias() -> None:
    class Model(BaseModel):
        resource_id: str = Field(alias="model_id")

        @property
        def model_id(self) -> str:
            return self.resource_id

    m = Model.construct(model_id="id")
    assert m.model_id == "id"
    assert m.resource_id == "id"
    assert m.resource_id is m.model_id

    m = parse_obj(Model, {"model_id": "id"})
    assert m.model_id == "id"
    assert m.resource_id == "id"
    assert m.resource_id is m.model_id


def test_omitted_fields() -> None:
    class Model(BaseModel):
        resource_id: Optional[str] = None

    m = Model.construct()
    assert "resource_id" not in m.model_fields_set

    m = Model.construct(resource_id=None)
    assert "resource_id" in m.model_fields_set

    m = Model.construct(resource_id="foo")
    assert "resource_id" in m.model_fields_set


def test_to_dict() -> None:
    class Model(BaseModel):
        foo: Optional[str] = Field(alias="FOO", default=None)

    m = Model(FOO="hello")
    assert m.to_dict() == {"FOO": "hello"}
    assert m.to_dict(use_api_names=False) == {"foo": "hello"}

    m2 = Model()
    assert m2.to_dict() == {}
    assert m2.to_dict(exclude_unset=False) == {"FOO": None}
    assert m2.to_dict(exclude_unset=False, exclude_none=True) == {}
    assert m2.to_dict(exclude_unset=False, exclude_defaults=True) == {}

    m3 = Model(FOO=None)
    assert m3.to_dict() == {"FOO": None}
    assert m3.to_dict(exclude_none=True) == {}
    assert m3.to_dict(exclude_defaults=True) == {}

    if PYDANTIC_V2:

        class Model2(BaseModel):
            created_at: datetime

        time_str = "2024-03-21T11:39:01.275859"
        m4 = Model2.construct(created_at=time_str)
        assert m4.to_dict(mode="python") == {"created_at": datetime.fromisoformat(time_str)}
        assert m4.to_dict(mode="json") == {"created_at": time_str}
    else:
        with pytest.raises(ValueError, match="mode is only supported in Pydantic v2"):
            m.to_dict(mode="json")

        with pytest.raises(ValueError, match="warnings is only supported in Pydantic v2"):
            m.to_dict(warnings=False)


def test_forwards_compat_model_dump_method() -> None:
    class Model(BaseModel):
        foo: Optional[str] = Field(alias="FOO", default=None)

    m = Model(FOO="hello")
    assert m.model_dump() == {"foo": "hello"}
    assert m.model_dump(include={"bar"}) == {}
    assert m.model_dump(exclude={"foo"}) == {}
    assert m.model_dump(by_alias=True) == {"FOO": "hello"}

    m2 = Model()
    assert m2.model_dump() == {"foo": None}
    assert m2.model_dump(exclude_unset=True) == {}
    assert m2.model_dump(exclude_none=True) == {}
    assert m2.model_dump(exclude_defaults=True) == {}

    m3 = Model(FOO=None)
    assert m3.model_dump() == {"foo": None}
    assert m3.model_dump(exclude_none=True) == {}

    if not PYDANTIC_V2:
        with pytest.raises(ValueError, match="mode is only supported in Pydantic v2"):
            m.model_dump(mode="json")

        with pytest.raises(ValueError, match="round_trip is only supported in Pydantic v2"):
            m.model_dump(round_trip=True)

        with pytest.raises(ValueError, match="warnings is only supported in Pydantic v2"):
            m.model_dump(warnings=False)


def test_to_json() -> None:
    class Model(BaseModel):
        foo: Optional[str] = Field(alias="FOO", default=None)

    m = Model(FOO="hello")
    assert json.loads(m.to_json()) == {"FOO": "hello"}
    assert json.loads(m.to_json(use_api_names=False)) == {"foo": "hello"}

    if PYDANTIC_V2:
        assert m.to_json(indent=None) == '{"FOO":"hello"}'
    else:
        assert m.to_json(indent=None) == '{"FOO": "hello"}'

    m2 = Model()
    assert json.loads(m2.to_json()) == {}
    assert json.loads(m2.to_json(exclude_unset=False)) == {"FOO": None}
    assert json.loads(m2.to_json(exclude_unset=False, exclude_none=True)) == {}
    assert json.loads(m2.to_json(exclude_unset=False, exclude_defaults=True)) == {}

    m3 = Model(FOO=None)
    assert json.loads(m3.to_json()) == {"FOO": None}
    assert json.loads(m3.to_json(exclude_none=True)) == {}

    if not PYDANTIC_V2:
        with pytest.raises(ValueError, match="warnings is only supported in Pydantic v2"):
            m.to_json(warnings=False)


def test_forwards_compat_model_dump_json_method() -> None:
    class Model(BaseModel):
        foo: Optional[str] = Field(alias="FOO", default=None)

    m = Model(FOO="hello")
    assert json.loads(m.model_dump_json()) == {"foo": "hello"}
    assert json.loads(m.model_dump_json(include={"bar"})) == {}
    assert json.loads(m.model_dump_json(include={"foo"})) == {"foo": "hello"}
    assert json.loads(m.model_dump_json(by_alias=True)) == {"FOO": "hello"}

    assert m.model_dump_json(indent=2) == '{\n  "foo": "hello"\n}'

    m2 = Model()
    assert json.loads(m2.model_dump_json()) == {"foo": None}
    assert json.loads(m2.model_dump_json(exclude_unset=True)) == {}
    assert json.loads(m2.model_dump_json(exclude_none=True)) == {}
    assert json.loads(m2.model_dump_json(exclude_defaults=True)) == {}

    m3 = Model(FOO=None)
    assert json.loads(m3.model_dump_json()) == {"foo": None}
    assert json.loads(m3.model_dump_json(exclude_none=True)) == {}

    if not PYDANTIC_V2:
        with pytest.raises(ValueError, match="round_trip is only supported in Pydantic v2"):
            m.model_dump_json(round_trip=True)

        with pytest.raises(ValueError, match="warnings is only supported in Pydantic v2"):
            m.model_dump_json(warnings=False)


def test_type_compat() -> None:
    # our model type can be assigned to Pydantic's model type

    def takes_pydantic(model: pydantic.BaseModel) -> None:  # noqa: ARG001
        ...

    class OurModel(BaseModel):
        foo: Optional[str] = None

    takes_pydantic(OurModel())


def test_annotated_types() -> None:
    class Model(BaseModel):
        value: str

    m = construct_type(
        value={"value": "foo"},
        type_=cast(Any, Annotated[Model, "random metadata"]),
    )
    assert isinstance(m, Model)
    assert m.value == "foo"


def test_discriminated_unions_invalid_data() -> None:
    class A(BaseModel):
        type: Literal["a"]

        data: str

    class B(BaseModel):
        type: Literal["b"]

        data: int

    m = construct_type(
        value={"type": "b", "data": "foo"},
        type_=cast(Any, Annotated[Union[A, B], PropertyInfo(discriminator="type")]),
    )
    assert isinstance(m, B)
    assert m.type == "b"
    assert m.data == "foo"  # type: ignore[comparison-overlap]

    m = construct_type(
        value={"type": "a", "data": 100},
        type_=cast(Any, Annotated[Union[A, B], PropertyInfo(discriminator="type")]),
    )
    assert isinstance(m, A)
    assert m.type == "a"
    if PYDANTIC_V2:
        assert m.data == 100  # type: ignore[comparison-overlap]
    else:
        # pydantic v1 automatically converts inputs to strings
        # if the expected type is a str
        assert m.data == "100"


def test_discriminated_unions_unknown_variant() -> None:
    class A(BaseModel):
        type: Literal["a"]

        data: str

    class B(BaseModel):
        type: Literal["b"]

        data: int

    m = construct_type(
        value={"type": "c", "data": None, "new_thing": "bar"},
        type_=cast(Any, Annotated[Union[A, B], PropertyInfo(discriminator="type")]),
    )

    # just chooses the first variant
    assert isinstance(m, A)
    assert m.type == "c"  # type: ignore[comparison-overlap]
    assert m.data == None  # type: ignore[unreachable]
    assert m.new_thing == "bar"


def test_discriminated_unions_invalid_data_nested_unions() -> None:
    class A(BaseModel):
        type: Literal["a"]

        data: str

    class B(BaseModel):
        type: Literal["b"]

        data: int

    class C(BaseModel):
        type: Literal["c"]

        data: bool

    m = construct_type(
        value={"type": "b", "data": "foo"},
        type_=cast(Any, Annotated[Union[Union[A, B], C], PropertyInfo(discriminator="type")]),
    )
    assert isinstance(m, B)
    assert m.type == "b"
    assert m.data == "foo"  # type: ignore[comparison-overlap]

    m = construct_type(
        value={"type": "c", "data": "foo"},
        type_=cast(Any, Annotated[Union[Union[A, B], C], PropertyInfo(discriminator="type")]),
    )
    assert isinstance(m, C)
    assert m.type == "c"
    assert m.data == "foo"  # type: ignore[comparison-overlap]


def test_discriminated_unions_with_aliases_invalid_data() -> None:
    class A(BaseModel):
        foo_type: Literal["a"] = Field(alias="type")

        data: str

    class B(BaseModel):
        foo_type: Literal["b"] = Field(alias="type")

        data: int

    m = construct_type(
        value={"type": "b", "data": "foo"},
        type_=cast(Any, Annotated[Union[A, B], PropertyInfo(discriminator="foo_type")]),
    )
    assert isinstance(m, B)
    assert m.foo_type == "b"
    assert m.data == "foo"  # type: ignore[comparison-overlap]

    m = construct_type(
        value={"type": "a", "data": 100},
        type_=cast(Any, Annotated[Union[A, B], PropertyInfo(discriminator="foo_type")]),
    )
    assert isinstance(m, A)
    assert m.foo_type == "a"
    if PYDANTIC_V2:
        assert m.data == 100  # type: ignore[comparison-overlap]
    else:
        # pydantic v1 automatically converts inputs to strings
        # if the expected type is a str
        assert m.data == "100"


def test_discriminated_unions_overlapping_discriminators_invalid_data() -> None:
    class A(BaseModel):
        type: Literal["a"]

        data: bool

    class B(BaseModel):
        type: Literal["a"]

        data: int

    m = construct_type(
        value={"type": "a", "data": "foo"},
        type_=cast(Any, Annotated[Union[A, B], PropertyInfo(discriminator="type")]),
    )
    assert isinstance(m, B)
    assert m.type == "a"
    assert m.data == "foo"  # type: ignore[comparison-overlap]


def test_discriminated_unions_invalid_data_uses_cache() -> None:
    class A(BaseModel):
        type: Literal["a"]

        data: str

    class B(BaseModel):
        type: Literal["b"]

        data: int

    UnionType = cast(Any, Union[A, B])

    assert not hasattr(UnionType, "__discriminator__")

    m = construct_type(
        value={"type": "b", "data": "foo"}, type_=cast(Any, Annotated[UnionType, PropertyInfo(discriminator="type")])
    )
    assert isinstance(m, B)
    assert m.type == "b"
    assert m.data == "foo"  # type: ignore[comparison-overlap]

    discriminator = UnionType.__discriminator__
    assert discriminator is not None

    m = construct_type(
        value={"type": "b", "data": "foo"}, type_=cast(Any, Annotated[UnionType, PropertyInfo(discriminator="type")])
    )
    assert isinstance(m, B)
    assert m.type == "b"
    assert m.data == "foo"  # type: ignore[comparison-overlap]

    # if the discriminator details object stays the same between invocations then
    # we hit the cache
    assert UnionType.__discriminator__ is discriminator