Parsing Bug - typing.List of Dataclass with an Enum

[sdupere-git]

This one is really strange and I could not troubleshoot it easily

• xs hides value and the generator can be called only once, so it's hard to troubleshoot

I can't provide the exact details but we have a parsing error (tried both from_dict and from_json).

Exact Error: Type List cannot be instantiated; use list() instead

This started when I added an enum inside a dataclass that is in a typing.List of another dataclass.

The datacclass format looks like this:

@dataclass_json @dataclass class Message:

---

my_list: typing.List[ListClass]

@dataclass_json @dataclass class ListClass:

---

enum_value:  MyEnum

We work around it with the following code:

A bug in dataclasses-json confuses the parsing.

enum_value: str = field(
    metadata=config(
        encoder=_get_enum_value,
        decoder=_get_enum_value_str))

[hmoravec]

I had the same problem. Adding str mix-in to the enum class as described in the official Python docs helped, ie.:

class MyEnum(str, Enum):
    ...

[matt035343]

I tried to repreduce this with the following code in the newest master version, but it ran just fine:

class MyEnum(enum.Enum):
    STR = "str"
    FLOAT = 1.0
    
@dataclass_json
@dataclass
class ListClass:
    enum_value: MyEnum

@dataclass_json
@dataclass
class Message:
   my_list: typing.List[ListClass]
    
Message.from_json('{"my_list":[{"enum_value":"str"}]}')

Message(my_list=[ListClass(enum_value=<MyEnum.STR: 'str'>)])

If you still face issues, please repoen with more details, e.g. Python version and dataclasses-json version.