Fix JsonRecordPacker when bytes field is None (#180)

Als fixed DeprecationWarning: The default datetime adapter is deprecated as of Python 3.12.

Author: yunzheng

flow/record/jsonpacker.py

@@ -97,7 +97,8 @@ def unpack_obj(self, obj: Any) -> RecordDescriptor | Record | Any:
                 del obj["_type"]
                 for field_type, field_name in record_descriptor.get_field_tuples():
                     if field_type == "bytes":
-                        obj[field_name] = base64.b64decode(obj[field_name])
+                        value = obj[field_name]
+                        obj[field_name] = base64.b64decode(value) if value is not None else None
                 return record_descriptor.recordType(**obj)
             if _type == "recorddescriptor":
                 data = obj["_data"]

tests/adapter/test_sqlite_duckdb.py

@@ -169,11 +169,12 @@ def test_read_from_sqlite(tmp_path: Path, db: Database) -> None:
             """
         )
         for i in range(1, 30):
+            dt_isoformat = datetime(2023, 10, i, 13, 37, tzinfo=timezone.utc).isoformat()
             con.execute(
                 """
                 INSERT INTO 'test/record' VALUES (?, ?, ?, ?)
                 """,
-                (f"record{i}", f"foobar{i}".encode(), datetime(2023, 10, i, 13, 37, tzinfo=timezone.utc), 3.14 + i),
+                (f"record{i}", f"foobar{i}".encode(), dt_isoformat, 3.14 + i),
             )
 
     # Read the SQLite database using flow.record

tests/packer/test_json_packer.py

@@ -112,3 +112,29 @@ def test_record_pack_surrogateescape() -> None:
 
     # pack the json string back to a record and make sure it is the same as before
     assert packer.unpack(data) == record
+
+
+def test_json_packer_bytes_type() -> None:
+    TestRecord = RecordDescriptor(
+        "test/bytes",
+        [
+            ("bytes", "data"),
+        ],
+    )
+
+    packer = JsonRecordPacker()
+
+    record = TestRecord(b"hello world")
+    data = packer.pack(record)
+    assert data.startswith('{"data": "aGVsbG8gd29ybGQ="')
+    assert packer.unpack(data) == record
+
+    record = TestRecord(data=None)
+    data = packer.pack(record)
+    assert data.startswith('{"data": null')
+    assert packer.unpack(data) == record
+
+    record = TestRecord(data=b"")
+    data = packer.pack(record)
+    assert data.startswith('{"data": ""')
+    assert packer.unpack(data) == record