Struct that contains an Enum property with a metaclass cant be decoded #822
Description
Description
I don't know if this is a bug, or just something that can't be supported. I've reviewed some of the other issues surrounding metaclasses and it seems there isn't a workaround.
This case is a little different though, my classes which inherit from Struct do not define a metaclass - but instead they have a property which is a subclass of Enum with a metaclass.
I put together a minimal reproducible example. Is it possible to support this use case?
from enum import Enum, EnumMeta
import msgspec
class BaseEnumSuccess(Enum):
...
class BaseEnumMeta(EnumMeta):
...
class BaseEnumFail(Enum, metaclass=BaseEnumMeta):
...
class EnumSuccess(BaseEnumSuccess):
Success = "success"
class EnumFail(BaseEnumFail):
Success = "success"
class TesterSuccess(msgspec.Struct):
variant: EnumSuccess
class TesterFail(msgspec.Struct):
variant: EnumFail
decoder_success = msgspec.json.Decoder(TesterSuccess)
decoded_success = decoder_success.decode(b'{"variant": "success"}')
print(decoded_success)
decoder_fail = msgspec.json.Decoder(TesterFail)
decoded_fail = decoder_fail.decode(b'{"variant": "success"}')
print(decoded_fail)Output:
TesterSuccess(variant=<EnumSuccess.Success: 'success'>)
Traceback (most recent call last):
File "/home/jonx/projects/py/example.py", line 39, in <module>
decoded_fail = decoder_fail.decode(b'{"variant": "success"}')
msgspec.ValidationError: Expected `EnumFail`, got `str` - at `$.variant`
Version info:
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Msgspec: 0.19.0
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Interpreter: CPython 3.13.1
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Compiler: GCC 14.2.1 20240910
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OS/Arch: Linux 6.6.72-1-lts / x86_64
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Thanks in advance for your time, love the library - it massively improved performance for me.