Handle numpy arrays when serializing (#579)

Fixes #578

src/blueapi/messaging/stomptemplate.py

@@ -8,6 +8,7 @@
 from threading import Event
 from typing import Any
 
+import orjson
 import stomp
 from pydantic import parse_obj_as
 from stomp.exception import ConnectFailedException
@@ -122,17 +123,20 @@ def send(
         correlation_id: str | None = None,
     ) -> None:
         self._send_str(
-            destination, json.dumps(serialize(obj)), on_reply, correlation_id
+            destination,
+            orjson.dumps(serialize(obj), option=orjson.OPT_SERIALIZE_NUMPY),
+            on_reply,
+            correlation_id,
         )
 
     def _send_str(
         self,
         destination: str,
-        message: str,
+        message: bytes,
         on_reply: MessageListener | None = None,
         correlation_id: str | None = None,
     ) -> None:
-        LOGGER.info(f"SENDING {message} to {destination}")
+        LOGGER.info(f"SENDING {message!r} to {destination}")
 
         headers: dict[str, Any] = {"JMSType": "TextMessage"}
         if on_reply is not None:

tests/messaging/test_stomptemplate.py

@@ -5,6 +5,7 @@
 from typing import Any
 from unittest.mock import ANY, MagicMock, call, patch
 
+import numpy as np
 import pytest
 from pydantic import BaseModel, BaseSettings, Field
 from stomp import Connection
@@ -148,7 +149,12 @@ class Foo(BaseModel):
 @pytest.mark.stomp
 @pytest.mark.parametrize(
     "message,message_type",
-    [("test", str), (1, int), (Foo(a=1, b="test"), Foo)],
+    [
+        ("test", str),
+        (1, int),
+        (Foo(a=1, b="test"), Foo),
+        (np.array([1, 2, 3]), list),
+    ],
 )
 def test_deserialization(
     template: MessagingTemplate, test_queue: str, message: Any, message_type: type
@@ -163,6 +169,8 @@ def server(ctx: MessageContext, message: message_type) -> None:  # type: ignore
     reply = template.send_and_receive(test_queue, message, message_type).result(
         timeout=_TIMEOUT
     )
+    if type(message) == np.ndarray:
+        message = message.tolist()
     assert reply == message