OmegaConf.structured does not parse dataclass attributes which are not typed

[carmocca]

Describe the bug

OmegaConf.structured does not parse dataclass attributes which are not typed

To Reproduce

from dataclasses import dataclass
from omegaconf import OmegaConf

@dataclass
class Foo:
    z = "test"  # No type

x = Foo()
y = OmegaConf.structured(x)
print(y) # {}

@dataclass
class Foo:
    z: str = "test"  # Typed

x = Foo()
y = OmegaConf.structured(x)
print(y) # {'z': 'test'}

Expected behavior
Both print the same thing

Alternatives
It works if I the type is set to Any. However, for my use case, I want to allow users to pass their own dataclasses, so I don't want to force them to have their dataclasses completely typed.

Additional context

• OmegaConf version: 2.1.0.dev14
• Python version: 3.8.6
• Operating system : Linux Pop-os

[omry]

Thanks for reporting.
This seems to be a problem in dataclasses and attr classes as well:

from dataclasses import dataclass, fields

@dataclass
class Foo:
    untyped = "foo"
    typed: str = "bar"

def print_fields(obj):
    obj_fields = fields(obj)
    for idx, field in enumerate(obj_fields):
        print(f"#{idx}: {field.name}")

print_fields(Foo)

Per BDFL, this is by design.
without a type it's not a field.

If you can find a clean way to access these fields (that works for both dataclasses and attr classes and instances) I am open to a PR.

Closing, feel free to continue the discussion here though.