From e8e0e81f62a898fd734d470ca6dcd2d9a8f641b4 Mon Sep 17 00:00:00 2001
From: appel_c <christian.appel@psi.ch>
Date: Thu, 5 Mar 2026 13:37:30 +0100
Subject: [PATCH] test(panda-box): Add tests for data readout loop and context
 manager

---
 tests/test_panda.py | 129 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 128 insertions(+), 1 deletion(-)

diff --git a/tests/test_panda.py b/tests/test_panda.py
index d864beb..e69b946 100644
--- a/tests/test_panda.py
+++ b/tests/test_panda.py
@@ -1,12 +1,22 @@
 # skip-file
+import socket
 from unittest import mock
 
 import numpy as np
 import pytest
 from ophyd import Staged
+from pandablocks.connections import NeedMoreDataError
 
 from ophyd_devices import StatusBase
-from ophyd_devices.devices.panda_box.panda_box import FrameData, PandaBox, PandaState
+from ophyd_devices.devices.panda_box.panda_box import (
+    EndData,
+    FrameData,
+    PandaBox,
+    PandaBoxDataConnection,
+    PandaState,
+    ReadyData,
+    StartData,
+)
 from ophyd_devices.devices.panda_box.utils import (
     PANDA_AVAIL_PCAP_BLOCKS,
     PANDA_AVAIL_PCAP_CAPTURE_FIELDS,
@@ -336,3 +346,120 @@ def test_panda_on_pre_scan(panda_box):
     status.wait(timeout=1)
     assert status.done, "Status should be done"
     assert status.success, "Status should be successful"
+
+
+def test_data_loop():
+    """Test that the data loop correctly handles receiving data and exiting on EndData."""
+    # Mock the exact class lookup used inside PandaBox._run_data_readout
+    with mock.patch(
+        "ophyd_devices.devices.panda_box.panda_box.PandaBoxDataConnection"
+    ) as mock_data_connection_cls:
+        panda_box = PandaBox(
+            name="panda_box", host="localhost", signal_alias={"FMC_IN.VAL1.Value": "my_signal_1"}
+        )
+
+        mock_data_connection = mock.MagicMock()
+        mock_socket_connection = mock.MagicMock()
+        mock_data_connection_cls.return_value.__enter__.return_value = (
+            mock_socket_connection,
+            mock_data_connection,
+        )
+
+        recv_items = [b"chunk1", b"chunk2", socket.timeout(), b"chunk3", b"chunk4", b"chunk5"]
+
+        def recv_side_effect(_buffer_size):
+            item = recv_items.pop(0)
+            if isinstance(item, Exception):
+                raise item
+            return item
+
+        def receive_bytes_side_effect(chunk):
+            if chunk == b"chunk1":
+                return [
+                    StartData(
+                        fields=["FMC_IN.VAL1.Value", "COUNTER2.OUT.Value"],
+                        missed=0,
+                        process="Scaled",
+                        format="Framed",
+                        sample_bytes=16,
+                        arm_time=None,
+                        start_time=None,
+                        hw_time_offset_ns=None,
+                    )
+                ]
+            if chunk == b"chunk2":
+                return [ReadyData()]
+            if chunk == b"chunk3":
+                return [
+                    FrameData(
+                        np.array(
+                            [(3, 4)],
+                            dtype=[("FMC_IN.VAL1.Value", "<f8"), ("COUNTER2.OUT.Value", "<f8")],
+                        )
+                    )
+                ]
+            if chunk == b"chunk4":
+                raise NeedMoreDataError()
+            if chunk == b"chunk5":
+                return [EndData(samples=200, reason="Ok")]
+            return []
+
+        mock_socket_connection.recv.side_effect = recv_side_effect
+        mock_data_connection.receive_bytes.side_effect = receive_bytes_side_effect
+
+        status_start = StatusBase(obj=panda_box)
+        status_ready = StatusBase(obj=panda_box)
+        status_frame = StatusBase(obj=panda_box)
+        status_end = StatusBase(obj=panda_box)
+        status_disarmed = StatusBase(obj=panda_box)
+
+        for status, expected_state in [
+            (status_start, PandaState.START),
+            (status_ready, PandaState.READY),
+            (status_frame, PandaState.FRAME),
+            (status_end, PandaState.END),
+            (status_disarmed, PandaState.DISARMED),
+        ]:
+            panda_box.add_status_callback(
+                status=status, success=[expected_state], failure=[], check_directly=False
+            )
+
+        assert panda_box.panda_state == PandaState.DISARMED, "Initial state should be DISARMED"
+
+        with (
+            mock.patch.object(panda_box.data, "put"),
+            mock.patch.object(panda_box, "_disarm") as mock_disarm,
+        ):
+            panda_box.data_thread_run_event.set()
+            panda_box._run_data_readout()
+
+            for status in [status_start, status_ready, status_frame, status_end, status_disarmed]:
+                assert status.done, f"{status} should be done"
+                assert status.success, f"{status} should be successful"
+
+        mock_data_connection_cls.assert_called_once_with(
+            "localhost", scaled=True, socket_timeout=0.1
+        )
+        mock_disarm.assert_called_once(), "_disarm should be called once after receiving EndData"
+
+        assert (
+            not panda_box.data_thread_run_event.is_set()
+        ), "Data thread run event should be unset after receiving EndData"
+
+
+def test_pandabox_data_connection():
+    """Test that PandaBoxDataConnection correctly connects and receives data."""
+    with mock.patch("socket.socket") as mock_socket_cls:
+        mock_socket = mock.MagicMock()
+        mock_socket_cls.return_value = mock_socket
+
+        with PandaBoxDataConnection("localhost", scaled=True, socket_timeout=0.1) as (
+            data_socket,
+            data_connection,
+        ):
+            mock_socket.connect.assert_called_once_with(("localhost", 8889))
+            expected_connect_command = "XML FRAMED SCALED\n"  # Connect command for scaled data
+            mock_socket.sendall.assert_called_once_with(expected_connect_command.encode())
+
+        # Simulate exiting the context manager, which should close the socket
+        mock_socket.close.assert_called_once()