def replace(__obj: T, **changes) -> T: # type: ignore
from apischema.fields import FIELDS_SET_ATTR, fields_set, set_fields
from dataclasses import replace as replace_
result = replace_(__obj, **changes)
if hasattr(__obj, FIELDS_SET_ATTR):
set_fields(result, *fields_set(__obj), *changes, overwrite=True)
return result
def _replace(__obj, **changes):
from apischema.fields import FIELDS_SET_ATTR, fields_set, set_fields
from dataclasses import replace as replace_, _FIELDS, _FIELD_INITVAR # type: ignore
# Fix https://bugs.python.org/issue36470
assert is_dataclass(__obj)
for name, field in getattr(__obj, _FIELDS).items():
if field._field_type == _FIELD_INITVAR and name not in changes: # type: ignore
if field.default is not MISSING:
changes[name] = field.default
elif field.default_factory is not MISSING:
changes[name] = field.default_factory()
result = replace_(__obj, **changes)
if hasattr(__obj, FIELDS_SET_ATTR):
set_fields(result, *fields_set(__obj), *changes, overwrite=True)
return result
def test_fields_set():
with raises(ValueError):
fields_set(object())
assert fields_set(Data(0)) == {"without_default"}
assert fields_set(Data(without_default=0)) == {"without_default"}
assert fields_set(Data(0, 1)) == {"without_default", "with_default"}
data = Data(0)
data.with_default = 1
assert fields_set(data) == {"without_default", "with_default"}
unset_fields(data, "without_default")
assert fields_set(data) == {"with_default"}
set_fields(data, "with_default_factory")
assert fields_set(data) == {"with_default", "with_default_factory"}
set_fields(data, "with_default", overwrite=True)
assert fields_set(data) == {"with_default"}
data.__dict__.pop(FIELDS_SET_ATTR)
assert fields_set(data) == {
"without_default",
"with_default",
"with_default_factory",
}
unset_fields(data, "without_default")
assert fields_set(data) == {"with_default", "with_default_factory"}
data.__dict__.pop(FIELDS_SET_ATTR)
set_fields(data, "with_default")
assert fields_set(data) == {
"without_default",
"with_default",
"with_default_factory",
}
with raises(ValueError):
set_fields(data, "not_a_field")
assert fields_set(Inherited(0, other=0)) == {
"without_default",
"with_default",
"with_default_factory",
"other",
}
assert fields_set(DecoratedInherited(0, other=0)) == {
"without_default",
"other",
}
def __init__(self, cls: Type, values: Mapping[str, Any]):
self.cls = cls
self.values = values
set_fields(self, *values, overwrite=True)
# This decorator enable the feature
@with_fields_set
@dataclass
class Foo:
bar: int
baz: Optional[str] = None
# Retrieve fields set
foo1 = Foo(0, None)
assert fields_set(foo1) == {"bar", "baz"}
foo2 = Foo(0)
assert fields_set(foo2) == {"bar"}
# Test fields individually (with autocompletion and refactoring)
assert is_set(foo1).baz
assert not is_set(foo2).baz
# Mark fields as set/unset
set_fields(foo2, "baz")
assert fields_set(foo2) == {"bar", "baz"}
unset_fields(foo2, "baz")
assert fields_set(foo2) == {"bar"}
set_fields(foo2, "baz", overwrite=True)
assert fields_set(foo2) == {"baz"}
# Fields modification are taken in account
foo2.bar = 0
assert fields_set(foo2) == {"bar", "baz"}
# Because deserialization use normal constructor, it works with the feature
foo3 = deserialize(Foo, {"bar": 0})
assert fields_set(foo3) == {"bar"}