Resolve "batchOrder json does not support booleans"

[claudeenriquez]

Summary

Encode the batchOrder JSON object into a JSON text before passing it into the URL encoder, to support boolean values inside the object.

Changes / Features

Example:

from kraken.futures import Trade

client = Trade(
    key=",
    secret="",
    url="https://demo-futures.kraken.com"
)

response = client.create_batch_order(batchorder_list=[
    {
        "order": "send",
        "order_tag": "test",
        "orderType": "post",
        "symbol": "PF_XBTUSD",
        "side": "buy",
        "size": "1",
        "limitPrice": "1",
        "reduceOnly": True,
    }
])

print(response)

Before fix:

{'result': 'error', 'error': 'Json Parse Error', 'serverTime': '2025-09-01T06:25:42.751Z'}

After fix:

{'result': 'success', 'serverTime': '2025-09-01T06:24:11.557Z', 'batchStatus': [{'status': 'placed', 'order_tag': 'test', 'order_id': '9fc58abf-220a-44d8-91ce-d47493981538', 'dateTimeReceived': '2025-09-01T06:24:11.555Z', 'orderEvents': [{'type': 'PLACE', 'order': {'orderId': '9fc58abf-220a-44d8-91ce-d47493981538', 'cliOrdId': None, 'type': 'post', 'symbol': 'PF_XBTUSD', 'side': 'buy', 'quantity': 1, 'filled': 0, 'limitPrice': 1, 'reduceOnly': False, 'timestamp': '2025-09-01T06:24:11.555Z', 'lastUpdateTimestamp': '2025-09-01T06:24:11.555Z'}, 'reducedQuantity': None}]}]}

Closes #392

[btschwertfeger]

Hello @claudeenriquez, thanks a lot for the bugfix proposal! Could you please open an issue first that describes the problem and expected behavior? That’ll help us keep a clear record for the future.

[claudeenriquez]

Hello @claudeenriquez, thanks a lot for the bugfix proposal! Could you please open an issue first that describes the problem and expected behavior? That’ll help us keep a clear record for the future.

Issue linked.

[btschwertfeger]

The proposed change looks absolutely legitimate and well-justified. Thanks for bringing it up! I double-checked your example, and it seems the required dumping comes from the boolean data type.

To make sure this works reliably now and going forward, could you please extend the unit test tests/futures/test_futures_trade.py::test_create_batch_order to include one order in the batchorderlist that sets "reduceOnly": True? That way we'll have full confidence the behavior stays correct in the future.

[claudeenriquez]

The proposed change looks absolutely legitimate and well-justified. Thanks for bringing it up! I double-checked your example, and it seems the required dumping comes from the boolean data type.

To make sure this works reliably now and going forward, could you please extend the unit test tests/futures/test_futures_trade.py::test_create_batch_order to include one order in the batchorderlist that sets "reduceOnly": True? That way we'll have full confidence the behavior stays correct in the future.

Done! Also ran pre-commit to pass the lint error.