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

FormSerializationWriter.write_bytes_value writes bytes as base64, but
FormParseNode.get_bytes_value returned the base64 text encoded as UTF-8
instead of decoding it, so a value written by the writer did not read
back as the original bytes.

Decode the value with base64.b64decode, as the JSON (#646) and text
parse nodes do.

Author: protonnegativo

packages/serialization/form/kiota_serialization_form/form_parse_node.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import base64
 import warnings
 from collections import defaultdict
 from collections.abc import Callable
@@ -380,7 +381,7 @@ def _get_time_value(value: str) -> Optional[time]:
     def _get_bytes_value(value: str) -> Optional[bytes]:
         if value and value != "null":
             try:
-                return str(value).encode("utf-8")
+                return base64.b64decode(value)
             except:
                 return None
         return None

packages/serialization/form/tests/unit/test_form_parse_node.py

@@ -1,4 +1,3 @@
-import base64
 from datetime import date, datetime, time, timedelta, timezone
 from enum import Enum
 from uuid import UUID
@@ -134,7 +133,27 @@ def test_get_bytes_value():
     parse_node = FormParseNode('SGVsbG8gd29ybGQ%3D')
     result = parse_node.get_bytes_value()
     assert isinstance(result, bytes)
-    assert base64.b64decode(result) == b'Hello world'
+    assert result == b'Hello world'
+
+
+def test_get_bytes_value_round_trip():
+    writer = FormSerializationWriter()
+    writer.write_bytes_value('data', b'Hello world')
+    content = writer.get_serialized_content().decode('utf-8')
+    parse_node = FormParseNode(content)
+    result = parse_node.get_child_node('data').get_bytes_value()
+    assert result == b'Hello world'
+
+
+def test_get_bytes_value_invalid_base64():
+    parse_node = FormParseNode('abc')
+    assert parse_node.get_bytes_value() is None
+
+
+def test_get_collection_of_bytes_values():
+    parse_node = FormParseNode('data=SGVsbG8%3D&data=d29ybGQ%3D')
+    result = parse_node.get_child_node('data').get_collection_of_primitive_values(bytes)
+    assert result == [b'Hello', b'world']
 
 def test_get_collection_of_numerical_primitive_values():
     TEST_FORM_DATA = "numbers=1&numbers=2&numbers=3&"