Add test for dataclass json encoding

tests/test_jsonable_encoder.py

@@ -1,3 +1,4 @@
+from dataclasses import dataclass
 from datetime import datetime, timezone
 from enum import Enum
 from pathlib import PurePath, PurePosixPath, PureWindowsPath
@@ -19,6 +20,12 @@ def __init__(self, owner: Person, name: str):
         self.name = name
 
 
+@dataclass
+class Item:
+    name: str
+    count: int
+
+
 class DictablePerson(Person):
     def __iter__(self):
         return ((k, v) for k, v in self.__dict__.items())
@@ -131,6 +138,15 @@ def test_encode_dictable():
     }
 
 
+def test_encode_dataclass():
+    item = Item(name="foo", count=100)
+    assert jsonable_encoder(item) == {"name": "foo", "count": 100}
+    assert jsonable_encoder(item, include={"name"}) == {"name": "foo"}
+    assert jsonable_encoder(item, exclude={"count"}) == {"name": "foo"}
+    assert jsonable_encoder(item, include={}) == {}
+    assert jsonable_encoder(item, exclude={}) == {"name": "foo", "count": 100}
+
+
 def test_encode_unsupported():
     unserializable = Unserializable()
     with pytest.raises(ValueError):