from typing import Optional, Union
import strawberry


@strawberry.type
class UnionTypeOne:
    field: str

# this is missing a @strawberry.type
class UnionTypeTwo:
    field: str


United = Union[
    UnionTypeOne,
    UnionTypeTwo,
]


@strawberry.type
class Transaction:
    title: str
    details: Optional[United] = None


@strawberry.type
class Query:
    @strawberry.field
    def test(self) -> Transaction:
        return Transaction(title="title")


schema = strawberry.Schema(query=Query)