Incorrect handling of Union types about apispec

[Amwam]

I think i may have found a solution, by adding a custom attribute function

def convert_union_to_spec(self, field, **kwargs):
    ret = {}
    if isinstance(field, marshmallow_dataclass.union_field.Union):
        ret["oneOf"] = [self.field2property(f[1]) for f in field.union_fields]

    return ret


ma_plugin.converter.add_attribute_function(convert_union_to_spec)

Would still appreciate some guidance if this is the right approach. Thanks!

[lafrech]

I'm not familiar with dataclass so I can't provide an educated advice.

This custom attribute function looks good to me.