OmegaConf.to_object handling of init=False fields

news/789.bugfix

@@ -0,0 +1 @@
+`OmegaConf.to_object` now works properly with structured configs that have `init=False` fields

omegaconf/_utils.py

@@ -268,10 +268,14 @@ def extract_dict_subclass_data(obj: Any, parent: Any) -> Optional[Dict[str, Any]
         return None
 
 
-def get_attr_class_field_names(obj: Any) -> List[str]:
+def get_attr_class_init_field_names(obj: Any) -> List[str]:
     is_type = isinstance(obj, type)
     obj_type = obj if is_type else type(obj)
-    return list(attr.fields_dict(obj_type))
+    return [
+        fieldname
+        for fieldname, attribute in attr.fields_dict(obj_type).items()
+        if attribute.init
+    ]
 
 
 def get_attr_data(obj: Any, allow_objects: Optional[bool] = None) -> Dict[str, Any]:
@@ -321,8 +325,8 @@ def get_attr_data(obj: Any, allow_objects: Optional[bool] = None) -> Dict[str, A
     return d
 
 
-def get_dataclass_field_names(obj: Any) -> List[str]:
-    return [field.name for field in dataclasses.fields(obj)]
+def get_dataclass_init_field_names(obj: Any) -> List[str]:
+    return [field.name for field in dataclasses.fields(obj) if field.init]
 
 
 def get_dataclass_data(
@@ -421,11 +425,11 @@ def is_structured_config_frozen(obj: Any) -> bool:
     return False
 
 
-def get_structured_config_field_names(obj: Any) -> List[str]:
+def get_structured_config_init_field_names(obj: Any) -> List[str]:
     if is_dataclass(obj):
-        return get_dataclass_field_names(obj)
+        return get_dataclass_init_field_names(obj)
     elif is_attr_class(obj):
-        return get_attr_class_field_names(obj)
+        return get_attr_class_init_field_names(obj)
     else:
         raise ValueError(f"Unsupported type: {type(obj).__name__}")
 

omegaconf/dictconfig.py

@@ -28,7 +28,7 @@
     _valid_dict_key_annotation_type,
     format_and_raise,
     get_structured_config_data,
-    get_structured_config_field_names,
+    get_structured_config_init_field_names,
     get_type_of,
     get_value_kind,
     is_container_annotation,
@@ -727,10 +727,10 @@ def _to_object(self) -> Any:
 
         object_type = self._metadata.object_type
         assert is_structured_config(object_type)
-        object_type_field_names = set(get_structured_config_field_names(object_type))
+        init_field_names = set(get_structured_config_init_field_names(object_type))
 
-        field_items: Dict[str, Any] = {}
-        nonfield_items: Dict[str, Any] = {}
+        init_field_items: Dict[str, Any] = {}
+        non_init_field_items: Dict[str, Any] = {}
         for k in self.keys():
             assert isinstance(k, str)
             node = self._get_node(k)
@@ -740,6 +740,8 @@ def _to_object(self) -> Any:
             except InterpolationResolutionError as e:
                 self._format_and_raise(key=k, value=None, cause=e)
             if node._is_missing():
+                if k not in init_field_names:
+                    continue  # MISSING is ignored for init=False fields
                 self._format_and_raise(
                     key=k,
                     value=None,
@@ -752,12 +754,12 @@ def _to_object(self) -> Any:
             else:
                 v = node._value()
 
-            if k in object_type_field_names:
-                field_items[k] = v
+            if k in init_field_names:
+                init_field_items[k] = v
             else:
-                nonfield_items[k] = v
+                non_init_field_items[k] = v
 
-        result = object_type(**field_items)
-        for k, v in nonfield_items.items():
+        result = object_type(**init_field_items)
+        for k, v in non_init_field_items.items():
             setattr(result, k, v)
         return result

tests/structured_conf/data/attr_classes.py

@@ -607,3 +607,13 @@ class ParentContainers:
     class ChildContainers(ParentContainers):
         list1: List[int] = [1, 2, 3]
         dict: Dict[str, Any] = {"a": 5, "b": 6}
+
+
+@attr.s(auto_attribs=True)
+class HasInitFalseFields:
+    post_initialized: str = attr.field(init=False)
+    without_default: str = attr.field(init=False)
+    with_default: str = attr.field(init=False, default="default")
+
+    def __attrs_post_init__(self) -> None:
+        self.post_initialized = "set_by_post_init"

tests/structured_conf/data/dataclasses.py

@@ -628,3 +628,13 @@ class ParentContainers:
     class ChildContainers(ParentContainers):
         list1: List[int] = field(default_factory=lambda: [1, 2, 3])
         dict: Dict[str, Any] = field(default_factory=lambda: {"a": 5, "b": 6})
+
+
+@dataclass
+class HasInitFalseFields:
+    post_initialized: str = field(init=False)
+    without_default: str = field(init=False)
+    with_default: str = field(init=False, default="default")
+
+    def __post_init__(self) -> None:
+        self.post_initialized = "set_by_post_init"

tests/test_to_container.py

@@ -430,6 +430,42 @@ def test_setattr_for_user_with_extra_field(self, module: Any) -> None:
         assert type(user) is module.User
         assert user.extra_field == 123
 
+    def test_init_false_with_default(self, module: Any) -> None:
+        cfg = OmegaConf.structured(module.HasInitFalseFields)
+        assert cfg.with_default == "default"
+        data = self.round_trip_to_object(cfg)
+        assert data.with_default == "default"
+
+    def test_init_false_with_default_overridden(self, module: Any) -> None:
+        cfg = OmegaConf.structured(module.HasInitFalseFields)
+        cfg.with_default = "default_overridden"
+        data = self.round_trip_to_object(cfg)
+        assert data.with_default == "default_overridden"
+
+    def test_init_false_without_default(self, module: Any) -> None:
+        cfg = OmegaConf.structured(module.HasInitFalseFields)
+        assert OmegaConf.is_missing(cfg, "without_default")
+        data = self.round_trip_to_object(cfg)
+        assert not hasattr(data, "without_default")
+
+    def test_init_false_without_default_overridden(self, module: Any) -> None:
+        cfg = OmegaConf.structured(module.HasInitFalseFields)
+        cfg.with_default = "default_overridden"
+        data = self.round_trip_to_object(cfg)
+        assert data.with_default == "default_overridden"
+
+    def test_init_false_post_initialized(self, module: Any) -> None:
+        cfg = OmegaConf.structured(module.HasInitFalseFields)
+        assert OmegaConf.is_missing(cfg, "post_initialized")
+        data = self.round_trip_to_object(cfg)
+        assert data.post_initialized == "set_by_post_init"
+
+    def test_init_false_post_initialized_overridden(self, module: Any) -> None:
+        cfg = OmegaConf.structured(module.HasInitFalseFields)
+        cfg.post_initialized = "overridden"
+        data = self.round_trip_to_object(cfg)
+        assert data.post_initialized == "overridden"
+
 
 class TestEnumToStr:
     """Test the `enum_to_str` argument to the `OmegaConf.to_container function`"""

tests/test_utils.py

@@ -151,6 +151,7 @@ class _TestDataclass:
     e: _TestEnum = _TestEnum.A
     list1: List[int] = field(default_factory=list)
     dict1: Dict[str, int] = field(default_factory=dict)
+    init_false: str = field(init=False, default="foo")
 
 
 @attr.s(auto_attribs=True)
@@ -163,6 +164,7 @@ class _TestAttrsClass:
     e: _TestEnum = _TestEnum.A
     list1: List[int] = []
     dict1: Dict[str, int] = {}
+    init_false: str = attr.field(init=False, default="foo")
 
 
 @dataclass
@@ -226,12 +228,12 @@ def test_get_structured_config_data_throws_ValueError(self) -> None:
         [_TestDataclass, _TestDataclass(), _TestAttrsClass, _TestAttrsClass()],
     )
     def test_get_structured_config_field_names(self, test_cls_or_obj: Any) -> None:
-        field_names = _utils.get_structured_config_field_names(test_cls_or_obj)
+        field_names = _utils.get_structured_config_init_field_names(test_cls_or_obj)
         assert field_names == ["x", "s", "b", "d", "f", "e", "list1", "dict1"]
 
     def test_get_structured_config_field_names_throws_ValueError(self) -> None:
         with raises(ValueError):
-            _utils.get_structured_config_field_names("invalid")
+            _utils.get_structured_config_init_field_names("invalid")
 
 
 @mark.parametrize(