test de/serializing ALL ufoLib2.objects

and in fact I had forgotten to decorate one of them (Info) ;)

tests/serde/test_serde.py

@@ -1,11 +1,12 @@
 import importlib
 import sys
-from typing import Any
+from typing import Any, Dict, List
 
 import pytest
 from attrs import define
 
-from ufoLib2.serde import serde
+import ufoLib2.objects
+from ufoLib2.serde import _SERDE_FORMATS_, serde
 
 
 def test_raise_import_error(monkeypatch: Any) -> None:
@@ -27,3 +28,42 @@ class Foo:
         # since the method is only added dynamicall at runtime, mypy complains that
         # "Foo" has no attribute "msgpack_dumps" -- so I shut it up
         foo.msgpack_dumps()  # type: ignore
+
+
+BASIC_EMPTY_OBJECTS: List[Dict[str, Any]] = [
+    {"class_name": "Anchor", "args": (0, 0)},
+    {"class_name": "Component", "args": ("a",)},
+    {"class_name": "Contour", "args": ()},
+    {"class_name": "DataSet", "args": ()},
+    {"class_name": "Features", "args": ()},
+    {"class_name": "Font", "args": ()},
+    {"class_name": "Glyph", "args": ()},
+    {"class_name": "Guideline", "args": (1,)},
+    {"class_name": "Image", "args": ()},
+    {"class_name": "ImageSet", "args": ()},
+    {"class_name": "Info", "args": ()},
+    {"class_name": "Kerning", "args": ()},
+    {"class_name": "Layer", "args": ()},
+    {
+        "class_name": "LayerSet",
+        "args": ({"public.default": ufoLib2.objects.Layer()},),
+    },
+    {"class_name": "Lib", "args": ()},
+    {"class_name": "Point", "args": (2, 3)},
+]
+assert {d["class_name"] for d in BASIC_EMPTY_OBJECTS} == set(ufoLib2.objects.__all__)
+
+
+@pytest.mark.parametrize("fmt", _SERDE_FORMATS_)
+@pytest.mark.parametrize(
+    "object_info",
+    BASIC_EMPTY_OBJECTS,
+    ids=lambda x: x["class_name"],  # type: ignore
+)
+def test_serde_all_objects(fmt: str, object_info: Dict[str, Any]) -> None:
+    klass = getattr(ufoLib2.objects, object_info["class_name"])
+    loads = getattr(klass, f"{fmt}_loads")
+    obj = klass(*object_info["args"])
+    dumps = getattr(obj, f"{fmt}_dumps")
+    obj2 = loads(dumps())
+    assert obj == obj2