Fix loading of an empty file via a file-pointer to return an empty di…

…ctionary (omry#404)

news/403.bugfix

@@ -0,0 +1 @@
+Fix loading of an empty file via a file-pointer to return an empty dictionary

omegaconf/omegaconf.py

@@ -283,21 +283,23 @@ def load(file_: Union[str, pathlib.Path, IO[Any]]) -> Union[DictConfig, ListConf
         if isinstance(file_, (str, pathlib.Path)):
             with io.open(os.path.abspath(file_), "r", encoding="utf-8") as f:
                 obj = yaml.load(f, Loader=get_yaml_loader())
-                if obj is None:
-                    res = OmegaConf.create()
-                else:
-                    res = OmegaConf.create(obj)
-                assert isinstance(res, (ListConfig, DictConfig))
-                return res
         elif getattr(file_, "read", None):
             obj = yaml.load(file_, Loader=get_yaml_loader())
-            assert isinstance(
-                obj, (list, dict, str)
-            ), f"Invalid loaded object type : {type(obj).__name__}"
-            return OmegaConf.create(obj)
         else:
             raise TypeError("Unexpected file type")
 
+        if obj is not None and not isinstance(obj, (list, dict, str)):
+            raise IOError(  # pragma: no cover
+                f"Invalid loaded object type : {type(obj).__name__}"
+            )
+
+        ret: Union[DictConfig, ListConfig]
+        if obj is None:
+            ret = OmegaConf.create()
+        else:
+            ret = OmegaConf.create(obj)
+        return ret
+
     @staticmethod
     def save(
         config: Any, f: Union[str, pathlib.Path, IO[Any]], resolve: bool = False

tests/test_serialization.py

@@ -182,3 +182,6 @@ def test_load_empty_file(tmpdir: str) -> None:
     empty.touch()
 
     assert OmegaConf.load(empty) == {}
+
+    with open(empty) as f:
+        assert OmegaConf.load(f) == {}