added base64

mesop/dataclass_utils/dataclass_utils.py

@@ -8,8 +8,10 @@
 from deepdiff.path import parse_path
 
 from mesop.exceptions import MesopException
+import base64 # Import base64 for encoding
 
 _PANDAS_OBJECT_KEY = "__pandas.DataFrame__"
+_BYTES_OBJECT_KEY = "__python.bytes__" # Add new key for bytes
 _DIFF_ACTION_DATA_FRAME_CHANGED = "data_frame_changed"
 
 C = TypeVar("C")
@@ -125,6 +127,9 @@ def default(self, obj):
     except ImportError:
       pass
 
+    if isinstance(obj, bytes):
+      return {_BYTES_OBJECT_KEY: base64.b64encode(obj).decode('utf-8')} # Encode bytes
+
     if is_dataclass(obj):
       return asdict(obj)
 
@@ -149,6 +154,10 @@ def decode_mesop_json_state_hook(dct):
 
     if _PANDAS_OBJECT_KEY in dct:
       return pd.read_json(StringIO(dct[_PANDAS_OBJECT_KEY]), orient="table")
+
+  if _BYTES_OBJECT_KEY in dct:
+    return base64.b64decode(dct[_BYTES_OBJECT_KEY]) # Decode bytes
+
   return dct
 
 
@@ -218,4 +227,4 @@ def diff_state(state1: Any, state2: Any) -> str:
     Delta(differences, always_include_values=True).to_flat_dicts()
     + custom_actions,
     cls=MesopJSONEncoder,
-  )
+  )

mesop/dataclass_utils/dataclass_utils_test.py

@@ -33,6 +33,11 @@ class WithPandasDataFrame:
   val: pd.DataFrame | None = None
 
 
+@dataclass
+class WithBytes:
+  data: bytes = b""
+
+
 JSON_STR = """{"b": {"c": {"val": "<init>"}},
 "list_b": [
   {"c": {"val": "1"}},
@@ -128,6 +133,20 @@ def test_serialize_pandas_dataframe():
   )
 
 
+@pytest.mark.parametrize(
+  "input_bytes, expected_json",
+  [
+  (b"hello world", '{"data": {"__python.bytes__": "aGVsbG8gd29ybGQ="}}'),
+  (b"", '{"data": {"__python.bytes__": ""}}'),
+  (b"unicode \xe2\x9c\x93", '{"data": {"__python.bytes__": "dW5pY29kZSDijJM="}}'),
+  ],
+)
+
+def test_serialize_bytes(input_bytes, expected_json):
+  serialized_dataclass = serialize_dataclass(WithBytes(data=input_bytes))
+  assert serialized_dataclass == expected_json
+
+
 def test_update_dataclass_from_json_nested_dataclass():
   b = B()
   update_dataclass_from_json(b, """{"c": {"val": "<init>"}}""")
@@ -191,5 +210,13 @@ def test_update_dataclass_with_pandas_dataframe():
   )
 
 
+def test_update_dataclass_with_bytes():
+    bytes_data = b"hello world"
+    serialized_dataclass = serialize_dataclass(WithBytes(data=bytes_data))
+    bytes_state = WithBytes()
+    update_dataclass_from_json(bytes_state, serialized_dataclass)
+    assert bytes_state.data == bytes_data
+
+
 if __name__ == "__main__":
   raise SystemExit(pytest.main([__file__]))

mesop/dataclass_utils/diff_state_test.py

@@ -410,6 +410,23 @@ class C:
   ]
 
 
+def test_diff_bytes():
+@dataclass
+class C:
+  val1: bytes = b"val1"
+
+s1 = C()
+s2 = C(val1=b"VAL1")
+
+assert json.loads(diff_state(s1, s2)) == [
+  {
+    "path": ["val1"],
+    "action": "values_changed",
+    "value": {"__python.bytes__": "VkFMMS=="},
+  }
+]
+
+
 def test_diff_not_dataclass():
   class C:
     val1: set[int] = field(default_factory=lambda: {1, 2, 3})