Top-level generic value does not deserialize correctly

[indigoviolet]

from serde import serde
from serde.yaml import from_yaml
from typing import Generic, TypeVar

yaml = """
foo: 1
bar:
    bar: 2
"""

T = TypeVar("T")


@serde
class Bar(Generic[T]):
    bar: T


@serde
class Foo(Generic[T]):
    foo: T
    bar: Bar[T]


# prints Foo(foo=1, bar=Bar(bar='2'))
# but should Foo.foo should be a str as well
from_yaml(Foo[str], yaml)

[yukinarit]

Hi @indigoviolet

pyserde depends on beartype package for type checks, and unfortunately, runtime generic parameters are not taken into account. Can you provide type boundaries for generic parameters?

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

so you can get error during deserializing

serde.compat.SerdeError: Method __main__.Foo.__init__() parameter foo=1 violates type hint ~T, as int 1 not instance of str.