Python 3.10's new Union syntax not working

[meshy]

Hello! I've discovered some problems when using the new python union syntax (PEP-604):

Observed behaviour (example extrapolated from existing tests):

>>> import jsons
>>> class C:
...     def __init__(self, x: str | None):
...         self.x = x
>>> jsons.dump(C("42"))
# Note: warning printed here reproduced below
{}

Expected behaviour:

>>> jsons.dump(C("42"))
{"x": 42}

Python version: 3.10.4
jsons version: 1.6.1

Note: this warning was in the observed output. I extracted it to reduce noise.
/.../jsons/_common_impl.py:43: UserWarning: Failed to dump attribute "42" of object of type "C". Reason: 'NoneType' object is not callable. Ignoring the attribute. Use suppress_warning(attribute-not-serialized) or suppress_warnings(True) to turn off this message. warnings.warn(msg_, *args, **kwargs)

Please let me know if I can provide more information.

[meshy]

As a work-around, I've been doing this to stop pyupgrade from changing my code to the new syntax in this case:

from typing import Optional
import jsons

str_or_none = Optional[int]

class C:
    def __init__(self, x: str_or_none):
        self.x = x

[ramonhagenaars]

Hi @meshy! Ah yes, the new pipe-syntax! I was hoping it would work out of the box, but apparently not.