Nonable fields don't work with type validations

[devashishshankar]

If I have a Nonable field, setting it to None, or calling a constructor with the field unspecified should not raise a validation error. However, this happens if I have typegaurd installed

Example code to reproduce:

class A:
     f: str = field(check_type=True, default=None, nonable=True)
     @init_fields
     def __init__():
            pass

a = A()

This results in the following traceback:

raceback (most recent call last):
  File "/Users/devashishshankar/Work/ddp_v1_venv/lib/python3.7/site-packages/pyfields/typing_utils.py", line 58, in assert_is_of_type
    check_type(field.qualname, value, typ)
  File "/Users/devashishshankar/Work/ddp_v1_venv/lib/python3.7/site-packages/typeguard/__init__.py", line 544, in check_type
    format(argname, qualified_name(expected_type), qualified_name(value)))
TypeError: type of A.f must be str; got NoneType instead

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<makefun-gen-36>", line 2, in __init__
  File "/Users/devashishshankar/Work/ddp_v1_venv/lib/python3.7/site-packages/pyfields/init_makers.py", line 446, in __init__
    setattr(self, field_name, field_value)
  File "/Users/devashishshankar/Work/ddp_v1_venv/lib/python3.7/site-packages/pyfields/core.py", line 1066, in __set__
    assert_is_of_type(self, value, t)
  File "/Users/devashishshankar/Work/ddp_v1_venv/lib/python3.7/site-packages/pyfields/typing_utils.py", line 63, in assert_is_of_type
    raise new_e
pyfields.typing_utils.FieldTypeError: Invalid value type provided for 'A.f'. Value should be of type <class 'str'>. Instead, received a 'NoneType': None

[smarie]

I am not able to reproduce the bug. Which version of pyfields do you use ? (you can see it using pyfields.__version__)

[smarie]

I finally found it, sorry. On the way for a patch

[smarie]

By the way I now configured travis so that it tests the three configuration : without anything installed / with pytypes / with typeguard