Test sizeof of Serialize and ToPickle

distributed/protocol/tests/test_protocol.py

@@ -6,6 +6,7 @@
 import pytest
 
 import dask
+from dask.sizeof import sizeof
 
 from distributed.protocol import dumps, loads, maybe_compress, msgpack, to_serialize
 from distributed.protocol.compression import (
@@ -15,8 +16,10 @@
 )
 from distributed.protocol.cuda import cuda_deserialize, cuda_serialize
 from distributed.protocol.serialize import (
+    Pickled,
     Serialize,
     Serialized,
+    ToPickle,
     dask_deserialize,
     dask_serialize,
     deserialize,
@@ -393,3 +396,19 @@ def _(header, frames):
     header, frames = serialize(MyObj(), serializers=serializers)
     o = deserialize(header, frames)
     assert isinstance(o, MyObj)
+
+
+@pytest.mark.parametrize(
+    "Wrapper, Wrapped",
+    [
+        (Serialize, Serialized),
+        (to_serialize, Serialized),
+        (ToPickle, Pickled),
+    ],
+)
+def test_sizeof_serialize(Wrapper, Wrapped):
+    size = 100_000
+    ser_obj = Wrapper(b"0" * size)
+    assert size <= sizeof(ser_obj) < size * 1.05
+    serialized = Wrapped(*serialize(ser_obj))
+    assert size <= sizeof(serialized) < size * 1.05