def const_default()

in chz/validators.py [0:0]

• 11 lines of code
• 3 McCabe index (conditional complexity)

def const_default(self: Any, attr: str) -> None:
    """Check the attribute matches the field's default value."""
    from chz.util import _MISSING_TYPE

    field: Field = self.__chz_fields__[attr.removeprefix("X_")]
    default = field._default
    if isinstance(default, _MISSING_TYPE):
        raise ValueError(
            "const_default requires a default value (default_factory is not supported)"
        )

    value = getattr(self, attr)
    if value != default:
        raise ValueError(f"Expected {attr} to match the default {default!r}, got {value!r}")