fix(json): base64-decode bytes values on deserialization

packages/serialization/json/kiota_serialization_json/json_parse_node.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import base64
 import json
 import re
 import warnings
@@ -290,15 +291,9 @@ def _get_time_value(value: Any) -> Optional[time]:
 
     @staticmethod
     def _get_bytes_value(value: Any) -> Optional[bytes]:
-        # if the node is a string, we need to decode it
-        # This ensures that the string is properly converted to bytes
         if isinstance(value, str):
-            base64_string = value
-        else:
-            base64_string = json.dumps(value)
-        if not base64_string:
-            return None
-        return base64_string.encode("utf-8")
+            return base64.b64decode(value)
+        return None
 
     @property
     def on_before_assign_field_values(self) -> Optional[Callable[[Parsable], None]]:

packages/serialization/json/tests/unit/test_json_parse_node.py

@@ -120,14 +120,19 @@ def test_get_collection_of_primitive_values_no_type():
 def test_get_bytes_value():
     parse_node = JsonParseNode("U2Ftd2VsIGlzIHRoZSBiZXN0")
     result = parse_node.get_bytes_value()
-    assert isinstance(result, bytes)
-    assert result.decode("utf-8") == "U2Ftd2VsIGlzIHRoZSBiZXN0"
+    assert result == b"Samwel is the best"
 
 
-def test_get_bytes_json_compatible():
+def test_get_bytes_value_empty_string():
+    parse_node = JsonParseNode("")
+    result = parse_node.get_bytes_value()
+    assert result == b""
+
+
+def test_get_bytes_value_non_string_returns_none():
     parse_node = JsonParseNode({"test": 1})
     result = parse_node.get_bytes_value()
-    assert json.loads(result.decode("utf-8")) == {"test": 1}
+    assert result is None
 
 
 def test_get_collection_of_enum_values():