feat: add support for dataclasses._MISSING_TYPE

omegaconf/omegaconf.py

@@ -7,6 +7,7 @@
 import sys
 import warnings
 from collections import defaultdict
+from dataclasses import _MISSING_TYPE
 from contextlib import contextmanager, nullcontext
 from enum import Enum
 from textwrap import dedent
@@ -845,6 +846,8 @@ def _create_impl(  # noqa F811
 
             if obj is _DEFAULT_MARKER_:
                 obj = {}
+            if isinstance(obj, _MISSING_TYPE):
+                return OmegaConf.create({}, parent=parent, flags=flags)
             if isinstance(obj, str):
                 obj = yaml.load(obj, Loader=get_yaml_loader())
                 if obj is None:

tests/test_missing_type.py

@@ -0,0 +1,23 @@
+from dataclasses import dataclass, field
+from typing import List, Any
+from omegaconf import OmegaConf
+
+
+@dataclass
+class Example:
+    num: int
+
+
+@dataclass
+class TestConfig(Example):
+    common: Example = field(default_factory=Example)
+
+
+for k, field_info in TestConfig.__dataclass_fields__.items():
+    default_value = field_info.default
+    default_factory = field_info.default_factory
+    print(
+        f"Field: {k}, Default Value: {default_value}, Default Factory: {default_factory}"
+    )
+
+    mis = OmegaConf.structured(default_factory)