diff --git a/src/hyperion/external_interaction/ispyb/ispyb_store.py b/src/hyperion/external_interaction/ispyb/ispyb_store.py
index 6f90a8330..21e558e9c 100755
--- a/src/hyperion/external_interaction/ispyb/ispyb_store.py
+++ b/src/hyperion/external_interaction/ispyb/ispyb_store.py
@@ -87,9 +87,7 @@ def _begin_or_update_deposition(
                     )
                 )
             else:
-                assert (
-                    ispyb_ids.data_collection_group_id
-                ), "Attempt to update data collection without a data collection group ID"
+                assert ispyb_ids.data_collection_group_id, "Attempt to update data collection without a data collection group ID"
 
             grid_ids = list(ispyb_ids.grid_ids)
             data_collection_ids_out = list(ispyb_ids.data_collection_ids)
diff --git a/tests/conftest.py b/tests/conftest.py
index 63ca1d6f6..562361410 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -5,12 +5,13 @@
 import sys
 import threading
 from functools import partial
-from typing import Any, Callable, Generator, Optional, Sequence
+from typing import Any, Generator, Sequence
 from unittest.mock import MagicMock, patch
 
 import bluesky.plan_stubs as bps
 import pytest
 from bluesky.run_engine import RunEngine
+from bluesky.simulators import RunEngineSimulator
 from bluesky.utils import Msg
 from dodal.beamlines import i03
 from dodal.common.beamlines import beamline_utils
@@ -721,155 +722,6 @@ def extract_metafile(input_filename, output_filename):
             output_fo.write(metafile_fo.read())
 
 
-class RunEngineSimulator:
-    """This class simulates a Bluesky RunEngine by recording and injecting responses to messages according to the
-    bluesky Message Protocol (see bluesky docs for details).
-    Basic usage consists of
-    1) Registering various handlers to respond to anticipated messages in the experiment plan and fire any
-    needed callbacks.
-    2) Calling simulate_plan()
-    3) Examining the returned message list and making asserts against them"""
-
-    def __init__(self):
-        self.message_handlers = []
-        self.callbacks = {}
-        self.next_callback_token = 0
-
-    def add_handler_for_callback_subscribes(self):
-        """Add a handler that registers all the callbacks from subscribe messages so we can call them later.
-        You probably want to call this as one of the first things unless you have a good reason not to.
-        """
-        self.message_handlers.append(
-            MessageHandler(
-                lambda msg: msg.command == "subscribe",
-                lambda msg: self._add_callback(msg.args),
-            )
-        )
-
-    def add_handler(
-        self,
-        commands: Sequence[str],
-        obj_name: Optional[str],
-        handler: Callable[[Msg], object],
-    ):
-        """Add the specified handler for a particular message
-        Args:
-            commands: the command name for the message as defined in bluesky Message Protocol, or a sequence if more
-            than one matches
-            obj_name: the name property of the obj to match, can be None as not all messages have a name
-            handler: a lambda that accepts a Msg and returns an object; the object is sent to the current yield statement
-            in the generator, and is used when reading values from devices, the structure of the object depends on device
-            hinting.
-        """
-        if isinstance(commands, str):
-            commands = [commands]
-
-        self.message_handlers.append(
-            MessageHandler(
-                lambda msg: msg.command in commands
-                and (obj_name is None or (msg.obj and msg.obj.name == obj_name)),
-                handler,
-            )
-        )
-
-    def add_wait_handler(
-        self, handler: Callable[[Msg], None], group: str = "any"
-    ) -> None:
-        """Add a wait handler for a particular message
-        Args:
-            handler: a lambda that accepts a Msg, use this to execute any code that simulates something that's
-            supposed to complete when a group finishes
-            group: name of the group to wait for, default is any which matches them all
-        """
-        self.message_handlers.append(
-            MessageHandler(
-                lambda msg: msg.command == "wait"
-                and (group == "any" or msg.kwargs["group"] == group),
-                handler,
-            )
-        )
-
-    def fire_callback(self, document_name, document) -> None:
-        """Fire all the callbacks registered for this document type in order to simulate something happening
-        Args:
-             document_name: document name as defined in the Bluesky Message Protocol 'subscribe' call,
-             all subscribers filtering on this document name will be called
-             document: the document to send
-        """
-        for callback_func, callback_docname in self.callbacks.values():
-            if callback_docname == "all" or callback_docname == document_name:
-                callback_func(document_name, document)
-
-    def simulate_plan(self, gen: Generator[Msg, object, object]) -> list[Msg]:
-        """Simulate the RunEngine executing the plan
-        Args:
-            gen: the generator function that executes the plan
-        Returns:
-            a list of the messages generated by the plan
-        """
-        messages = []
-        send_value = None
-        try:
-            while msg := gen.send(send_value):
-                send_value = None
-                messages.append(msg)
-                LOGGER.debug(f"<{msg}")
-                if handler := next(
-                    (h for h in self.message_handlers if h.predicate(msg)), None
-                ):
-                    send_value = handler.runnable(msg)
-
-                if send_value:
-                    LOGGER.debug(f">send {send_value}")
-        except StopIteration:
-            pass
-        return messages
-
-    def _add_callback(self, msg_args):
-        self.callbacks[self.next_callback_token] = msg_args
-        self.next_callback_token += 1
-
-    def assert_message_and_return_remaining(
-        self,
-        messages: list[Msg],
-        predicate: Callable[[Msg], bool],
-        group: Optional[str] = None,
-    ):
-        """Find the next message matching the predicate, assert that we found it
-        Return: all the remaining messages starting from the matched message"""
-        indices = [
-            i
-            for i in range(len(messages))
-            if (
-                not group
-                or (messages[i].kwargs and messages[i].kwargs.get("group") == group)
-            )
-            and predicate(messages[i])
-        ]
-        assert indices, f"Nothing matched predicate {predicate}"
-        return messages[indices[0] :]
-
-    def mock_message_generator(
-        self,
-        function_name: str,
-    ) -> Callable[..., Generator[Msg, object, object]]:
-        """Returns a callable that returns a generator yielding a Msg object recording the call arguments.
-        This can be used to mock methods returning a bluesky plan or portion thereof, call it from within a unit test
-        using the RunEngineSimulator, and then perform asserts on the message to verify in-order execution of the plan
-        """
-
-        def mock_method(*args, **kwargs):
-            yield Msg(function_name, None, *args, **kwargs)
-
-        return mock_method
-
-
-class MessageHandler:
-    def __init__(self, p: Callable[[Msg], bool], r: Callable[[Msg], object]):
-        self.predicate = p
-        self.runnable = r
-
-
 @pytest.fixture
 def sim_run_engine():
     return RunEngineSimulator()
diff --git a/tests/unit_tests/device_setup_plans/test_dcm_pitch_roll_mirror_adjuster.py b/tests/unit_tests/device_setup_plans/test_dcm_pitch_roll_mirror_adjuster.py
index 4a9715f75..11fe41a2e 100644
--- a/tests/unit_tests/device_setup_plans/test_dcm_pitch_roll_mirror_adjuster.py
+++ b/tests/unit_tests/device_setup_plans/test_dcm_pitch_roll_mirror_adjuster.py
@@ -3,6 +3,7 @@
 
 import pytest
 from bluesky.run_engine import RunEngine
+from bluesky.simulators import RunEngineSimulator, assert_message_and_return_remaining
 from dodal.common.beamlines.beamline_parameters import GDABeamlineParameters
 from dodal.devices.focusing_mirror import (
     FocusingMirrorWithStripes,
@@ -165,51 +166,51 @@ def test_adjust_dcm_pitch_roll_vfm_from_lut(
     vfm: FocusingMirrorWithStripes,
     vfm_mirror_voltages: VFMMirrorVoltages,
     beamline_parameters: GDABeamlineParameters,
-    sim_run_engine,
+    sim_run_engine: RunEngineSimulator,
 ):
     sim_run_engine.add_handler_for_callback_subscribes()
     sim_run_engine.add_handler(
         "read",
-        "dcm-bragg_in_degrees",
         lambda msg: {"dcm-bragg_in_degrees": {"value": 5.0}},
+        "dcm-bragg_in_degrees",
     )
 
     messages = sim_run_engine.simulate_plan(
         adjust_dcm_pitch_roll_vfm_from_lut(undulator_dcm, vfm, vfm_mirror_voltages, 7.5)
     )
 
-    messages = sim_run_engine.assert_message_and_return_remaining(
+    messages = assert_message_and_return_remaining(
         messages,
         lambda msg: msg.command == "set"
         and msg.obj.name == "dcm-pitch_in_mrad"
         and abs(msg.args[0] - -0.75859) < 1e-5
         and msg.kwargs["group"] == "DCM_GROUP",
     )
-    messages = sim_run_engine.assert_message_and_return_remaining(
+    messages = assert_message_and_return_remaining(
         messages[1:],
         lambda msg: msg.command == "set"
         and msg.obj.name == "dcm-roll_in_mrad"
         and abs(msg.args[0] - 4.0) < 1e-5
         and msg.kwargs["group"] == "DCM_GROUP",
     )
-    messages = sim_run_engine.assert_message_and_return_remaining(
+    messages = assert_message_and_return_remaining(
         messages[1:],
         lambda msg: msg.command == "set"
         and msg.obj.name == "dcm-offset_in_mm"
         and msg.args == (25.6,)
         and msg.kwargs["group"] == "DCM_GROUP",
     )
-    messages = sim_run_engine.assert_message_and_return_remaining(
+    messages = assert_message_and_return_remaining(
         messages[1:],
         lambda msg: msg.command == "set"
         and msg.obj.name == "vfm-stripe"
         and msg.args == (MirrorStripe.RHODIUM,),
     )
-    messages = sim_run_engine.assert_message_and_return_remaining(
+    messages = assert_message_and_return_remaining(
         messages[1:],
         lambda msg: msg.command == "wait",
     )
-    messages = sim_run_engine.assert_message_and_return_remaining(
+    messages = assert_message_and_return_remaining(
         messages[1:],
         lambda msg: msg.command == "trigger" and msg.obj.name == "vfm-apply_stripe",
     )
@@ -223,17 +224,17 @@ def test_adjust_dcm_pitch_roll_vfm_from_lut(
         (6, 4),
         (7, -46),
     ):
-        messages = sim_run_engine.assert_message_and_return_remaining(
+        messages = assert_message_and_return_remaining(
             messages[1:],
             lambda msg: msg.command == "set"
             and msg.obj.name == f"vfm_mirror_voltages-voltage_channels-{channel}"
             and msg.args == (expected_voltage,),
         )
-    messages = sim_run_engine.assert_message_and_return_remaining(
+    messages = assert_message_and_return_remaining(
         messages[1:],
         lambda msg: msg.command == "wait" and msg.kwargs["group"] == "DCM_GROUP",
     )
-    messages = sim_run_engine.assert_message_and_return_remaining(
+    messages = assert_message_and_return_remaining(
         messages[1:],
         lambda msg: msg.command == "set"
         and msg.obj.name == "vfm-x_mm"
diff --git a/tests/unit_tests/device_setup_plans/test_setup_panda.py b/tests/unit_tests/device_setup_plans/test_setup_panda.py
index de7a8e15c..407a89607 100644
--- a/tests/unit_tests/device_setup_plans/test_setup_panda.py
+++ b/tests/unit_tests/device_setup_plans/test_setup_panda.py
@@ -5,6 +5,7 @@
 import pytest
 from bluesky.plan_stubs import null
 from bluesky.run_engine import RunEngine
+from bluesky.simulators import RunEngineSimulator
 from dodal.devices.fast_grid_scan import PandAGridScanParams
 from ophyd_async.panda import SeqTrigger
 
@@ -16,14 +17,14 @@
     setup_panda_for_flyscan,
 )
 
-from ...conftest import RunEngineSimulator
-
 
 def get_smargon_speed(x_step_size_mm: float, time_between_x_steps_ms: float) -> float:
     return x_step_size_mm / time_between_x_steps_ms
 
 
-def run_simulating_setup_panda_functions(plan: str, mock_load_device=MagicMock):
+def run_simulating_setup_panda_functions(
+    plan: str, sim_run_engine: RunEngineSimulator, mock_load_device=MagicMock
+):
     num_of_sets = 0
     num_of_waits = 0
     mock_panda = MagicMock()
@@ -37,11 +38,7 @@ def count_commands(msg):
             num_of_waits += 1
 
     sim = RunEngineSimulator()
-    sim.add_handler(
-        ["set", "wait"],
-        None,
-        count_commands,
-    )
+    sim.add_handler(["set", "wait"], count_commands)
 
     if plan == "setup":
         smargon_speed = get_smargon_speed(0.1, 1)
@@ -63,9 +60,9 @@ def count_commands(msg):
 
 
 @patch("hyperion.device_setup_plans.setup_panda.load_device")
-def test_setup_panda_performs_correct_plans(mock_load_device):
+def test_setup_panda_performs_correct_plans(mock_load_device, sim_run_engine):
     num_of_sets, num_of_waits = run_simulating_setup_panda_functions(
-        "setup", mock_load_device
+        "setup", sim_run_engine, mock_load_device
     )
     mock_load_device.assert_called_once()
     assert num_of_sets == 9
@@ -181,9 +178,7 @@ def assert_set_table_has_been_waited_on(*args, **kwargs):
     ), patch(
         "hyperion.device_setup_plans.setup_panda.bps.wait",
         MagicMock(side_effect=handle_wait),
-    ), patch(
-        "hyperion.device_setup_plans.setup_panda.load_device"
-    ), patch(
+    ), patch("hyperion.device_setup_plans.setup_panda.load_device"), patch(
         "hyperion.device_setup_plans.setup_panda.bps.abs_set"
     ):
         RE(
@@ -201,8 +196,10 @@ def assert_set_table_has_been_waited_on(*args, **kwargs):
 
 # It also would be useful to have some system tests which check that (at least)
 # all the blocks which were enabled on setup are also disabled on tidyup
-def test_disarm_panda_disables_correct_blocks():
-    num_of_sets, num_of_waits = run_simulating_setup_panda_functions("disarm")
+def test_disarm_panda_disables_correct_blocks(sim_run_engine):
+    num_of_sets, num_of_waits = run_simulating_setup_panda_functions(
+        "disarm", sim_run_engine
+    )
     assert num_of_sets == 6
     assert num_of_waits == 1
 
diff --git a/tests/unit_tests/experiment_plans/test_flyscan_xray_centre_plan.py b/tests/unit_tests/experiment_plans/test_flyscan_xray_centre_plan.py
index e5801af88..aecf97970 100644
--- a/tests/unit_tests/experiment_plans/test_flyscan_xray_centre_plan.py
+++ b/tests/unit_tests/experiment_plans/test_flyscan_xray_centre_plan.py
@@ -8,6 +8,7 @@
 import numpy as np
 import pytest
 from bluesky.run_engine import RunEngine, RunEngineResult
+from bluesky.simulators import assert_message_and_return_remaining
 from bluesky.utils import FailedStatus, Msg
 from dodal.beamlines import i03
 from dodal.common.beamlines.beamline_utils import clear_device
@@ -998,30 +999,30 @@ def test_read_hardware_during_collection_occurs_after_eiger_arm(
         )
         sim_run_engine.add_handler(
             "read",
-            "synchrotron-synchrotron_mode",
             lambda msg: {"values": {"value": SynchrotronMode.USER}},
+            "synchrotron-synchrotron_mode",
         )
         msgs = sim_run_engine.simulate_plan(
             run_gridscan(
                 fake_fgs_composite, test_fgs_params_panda_zebra, feature_controlled
             )
         )
-        msgs = sim_run_engine.assert_message_and_return_remaining(
+        msgs = assert_message_and_return_remaining(
             msgs, lambda msg: msg.command == "stage" and msg.obj.name == "eiger"
         )
-        msgs = sim_run_engine.assert_message_and_return_remaining(
+        msgs = assert_message_and_return_remaining(
             msgs,
             lambda msg: msg.command == "kickoff"
             and msg.obj == feature_controlled.fgs_motors,
         )
-        msgs = sim_run_engine.assert_message_and_return_remaining(
+        msgs = assert_message_and_return_remaining(
             msgs, lambda msg: msg.command == "create"
         )
-        msgs = sim_run_engine.assert_message_and_return_remaining(
+        msgs = assert_message_and_return_remaining(
             msgs,
             lambda msg: msg.command == "read" and msg.obj.name == "eiger_bit_depth",
         )
-        msgs = sim_run_engine.assert_message_and_return_remaining(
+        msgs = assert_message_and_return_remaining(
             msgs, lambda msg: msg.command == "save"
         )
 
diff --git a/tests/unit_tests/experiment_plans/test_grid_detection_plan.py b/tests/unit_tests/experiment_plans/test_grid_detection_plan.py
index ac122d3ad..774ff4378 100644
--- a/tests/unit_tests/experiment_plans/test_grid_detection_plan.py
+++ b/tests/unit_tests/experiment_plans/test_grid_detection_plan.py
@@ -4,6 +4,7 @@
 import numpy as np
 import pytest
 from bluesky.run_engine import RunEngine
+from bluesky.simulators import RunEngineSimulator
 from bluesky.utils import Msg
 from dodal.beamlines import i03
 from dodal.devices.backlight import Backlight
@@ -345,11 +346,11 @@ def decorated():
 def test_when_detected_grid_has_odd_y_steps_then_add_a_y_step_and_shift_grid(
     fake_logger: MagicMock,
     fake_devices,
+    sim_run_engine: RunEngineSimulator,
     test_config_files,
     odd,
 ):
     composite, _ = fake_devices
-    sim = RunEngineSimulator()
     params = OAVParameters("loopCentring", test_config_files["oav_config_json"])
     grid_width_microns = 161.2
     box_size_um = 20
@@ -382,19 +383,9 @@ def record_set(msg: Msg):
             if msg.obj.dotted_name in abs_sets.keys():
                 abs_sets[msg.obj.dotted_name].append(msg.args[0])
 
-    sim.add_handler(
-        "set",
-        None,
-        record_set,
-    )
-
-    sim.add_handler(
-        "read",
-        None,
-        handle_read,
-    )
-
-    sim.simulate_plan(
+    sim_run_engine.add_handler("set", record_set)
+    sim_run_engine.add_handler("read", handle_read)
+    sim_run_engine.simulate_plan(
         grid_detection_plan(
             composite,
             parameters=params,
diff --git a/tests/unit_tests/experiment_plans/test_oav_snapshot_plan.py b/tests/unit_tests/experiment_plans/test_oav_snapshot_plan.py
index 81b77c747..71fd0626e 100644
--- a/tests/unit_tests/experiment_plans/test_oav_snapshot_plan.py
+++ b/tests/unit_tests/experiment_plans/test_oav_snapshot_plan.py
@@ -2,6 +2,7 @@
 from unittest.mock import patch
 
 import pytest
+from bluesky.simulators import assert_message_and_return_remaining
 from dodal.devices.oav.oav_parameters import OAVParameters
 from dodal.devices.oav.utils import ColorMode
 
@@ -44,37 +45,37 @@ def test_oav_snapshot_plan_issues_rotations_and_generates_events(
         )
     )
 
-    msgs = sim_run_engine.assert_message_and_return_remaining(
+    msgs = assert_message_and_return_remaining(
         msgs,
         lambda msg: msg.command == "set"
         and msg.obj.name == "oav_cam_color_mode"
         and msg.args[0] == ColorMode.RGB1,
     )
-    msgs = sim_run_engine.assert_message_and_return_remaining(
+    msgs = assert_message_and_return_remaining(
         msgs,
         lambda msg: msg.command == "set"
         and msg.obj.name == "oav_cam_acquire_period"
         and msg.args[0] == 0.05,
     )
-    msgs = sim_run_engine.assert_message_and_return_remaining(
+    msgs = assert_message_and_return_remaining(
         msgs,
         lambda msg: msg.command == "set"
         and msg.obj.name == "oav_cam_acquire_time"
         and msg.args[0] == 0.075,
     )
-    msgs = sim_run_engine.assert_message_and_return_remaining(
+    msgs = assert_message_and_return_remaining(
         msgs,
         lambda msg: msg.command == "set"
         and msg.obj.name == "oav_cam_gain"
         and msg.args[0] == 1,
     )
-    msgs = sim_run_engine.assert_message_and_return_remaining(
+    msgs = assert_message_and_return_remaining(
         msgs,
         lambda msg: msg.command == "set"
         and msg.obj.name == "oav_zoom_controller"
         and msg.args[0] == "5.0x",
     )
-    msgs = sim_run_engine.assert_message_and_return_remaining(
+    msgs = assert_message_and_return_remaining(
         msgs,
         lambda msg: msg.command == "set"
         and msg.obj.name == "oav_snapshot_directory"
@@ -86,39 +87,39 @@ def test_oav_snapshot_plan_issues_rotations_and_generates_events(
         {"omega": 180, "filename": "100623_oav_snapshot_180"},
         {"omega": 270, "filename": "100623_oav_snapshot_270"},
     ]:
-        msgs = sim_run_engine.assert_message_and_return_remaining(
+        msgs = assert_message_and_return_remaining(
             msgs,
             lambda msg: msg.command == "set"
             and msg.obj.name == "smargon-omega"
             and msg.args[0] == expected["omega"]
             and msg.kwargs["group"] == OAV_SNAPSHOT_GROUP,
         )
-        msgs = sim_run_engine.assert_message_and_return_remaining(
+        msgs = assert_message_and_return_remaining(
             msgs,
             lambda msg: msg.command == "set"
             and msg.obj.name == "oav_snapshot_filename"
             and msg.args[0] == expected["filename"],
         )
-        msgs = sim_run_engine.assert_message_and_return_remaining(
+        msgs = assert_message_and_return_remaining(
             msgs,
             lambda msg: msg.command == "trigger"
             and msg.obj.name == "oav_snapshot"
             and msg.kwargs["group"] == OAV_SNAPSHOT_GROUP,
         )
-        msgs = sim_run_engine.assert_message_and_return_remaining(
+        msgs = assert_message_and_return_remaining(
             msgs,
             lambda msg: msg.command == "wait"
             and msg.kwargs["group"] == OAV_SNAPSHOT_GROUP,
         )
-        msgs = sim_run_engine.assert_message_and_return_remaining(
+        msgs = assert_message_and_return_remaining(
             msgs,
             lambda msg: msg.command == "create"
             and msg.kwargs["name"]
             == DocDescriptorNames.OAV_ROTATION_SNAPSHOT_TRIGGERED,
         )
-        msgs = sim_run_engine.assert_message_and_return_remaining(
+        msgs = assert_message_and_return_remaining(
             msgs, lambda msg: msg.command == "read" and msg.obj.name == "oav_snapshot"
         )
-        msgs = sim_run_engine.assert_message_and_return_remaining(
+        msgs = assert_message_and_return_remaining(
             msgs, lambda msg: msg.command == "save"
         )
diff --git a/tests/unit_tests/experiment_plans/test_pin_centre_then_xray_centre_plan.py b/tests/unit_tests/experiment_plans/test_pin_centre_then_xray_centre_plan.py
index 2f3f476ac..7ff6571a7 100644
--- a/tests/unit_tests/experiment_plans/test_pin_centre_then_xray_centre_plan.py
+++ b/tests/unit_tests/experiment_plans/test_pin_centre_then_xray_centre_plan.py
@@ -2,6 +2,7 @@
 
 import pytest
 from bluesky.run_engine import RunEngine
+from bluesky.simulators import RunEngineSimulator, assert_message_and_return_remaining
 from bluesky.utils import Msg
 from dodal.devices.detector.detector_motion import ShutterState
 from dodal.devices.synchrotron import SynchrotronMode
@@ -78,7 +79,7 @@ def test_when_pin_centre_xray_centre_called_then_detector_positioned(
     test_pin_centre_then_xray_centre_params: PinTipCentreThenXrayCentre,
     simple_beamline,
     test_config_files,
-    sim_run_engine,
+    sim_run_engine: RunEngineSimulator,
 ):
     mock_grid_callback.return_value.get_grid_parameters.return_value = {
         "transmission_frac": 1.0,
@@ -100,20 +101,20 @@ def test_when_pin_centre_xray_centre_called_then_detector_positioned(
 
     sim_run_engine.add_handler(
         "read",
-        "synchrotron-synchrotron_mode",
         lambda msg_: {"values": {"value": SynchrotronMode.SHUTDOWN}},
+        "synchrotron-synchrotron_mode",
     )
 
     def add_handlers_to_simulate_detector_motion(msg: Msg):
         sim_run_engine.add_handler(
             "read",
-            "detector_motion_shutter",
             lambda msg_: {"values": {"value": int(ShutterState.OPEN)}},
+            "detector_motion_shutter",
         )
         sim_run_engine.add_handler(
             "read",
-            "detector_motion_z_motor_done_move",
             lambda msg_: {"values": {"value": 1}},
+            "detector_motion_z_motor_done_move",
         )
 
     sim_run_engine.add_wait_handler(
@@ -128,7 +129,7 @@ def add_handlers_to_simulate_detector_motion(msg: Msg):
         ),
     )
 
-    messages = sim_run_engine.assert_message_and_return_remaining(
+    messages = assert_message_and_return_remaining(
         messages, lambda msg: msg.obj is simple_beamline.detector_motion.z
     )
     assert messages[0].args[0] == 100
@@ -136,12 +137,12 @@ def add_handlers_to_simulate_detector_motion(msg: Msg):
     assert messages[1].obj is simple_beamline.detector_motion.shutter
     assert messages[1].args[0] == 1
     assert messages[1].kwargs["group"] == CONST.WAIT.GRID_READY_FOR_DC
-    messages = sim_run_engine.assert_message_and_return_remaining(
+    messages = assert_message_and_return_remaining(
         messages[2:],
         lambda msg: msg.command == "wait"
         and msg.kwargs["group"] == CONST.WAIT.GRID_READY_FOR_DC,
     )
-    sim_run_engine.assert_message_and_return_remaining(
+    assert_message_and_return_remaining(
         messages[2:],
         lambda msg: msg.command == "open_run"
         and msg.kwargs["subplan_name"] == "do_fgs",
diff --git a/tests/unit_tests/experiment_plans/test_rotation_scan_plan.py b/tests/unit_tests/experiment_plans/test_rotation_scan_plan.py
index 5fb16eb5a..699b681a6 100644
--- a/tests/unit_tests/experiment_plans/test_rotation_scan_plan.py
+++ b/tests/unit_tests/experiment_plans/test_rotation_scan_plan.py
@@ -6,6 +6,7 @@
 
 import pytest
 from bluesky.run_engine import RunEngine
+from bluesky.simulators import RunEngineSimulator, assert_message_and_return_remaining
 from dodal.devices.aperturescatterguard import ApertureScatterguard
 from dodal.devices.synchrotron import SynchrotronMode
 from dodal.devices.zebra import Zebra
@@ -272,20 +273,20 @@ def test_rotation_plan_reads_hardware(
     fake_create_rotation_devices: RotationScanComposite,
     test_rotation_params,
     motion_values,
-    sim_run_engine,
+    sim_run_engine: RunEngineSimulator,
 ):
     sim_run_engine.add_handler(
         "read",
-        "synchrotron-synchrotron_mode",
         lambda msg: {"values": {"value": SynchrotronMode.USER}},
+        "synchrotron-synchrotron_mode",
     )
     sim_run_engine.add_handler(
         "read",
-        "synchrotron-top_up_start_countdown",
         lambda msg: {"values": {"value": -1}},
+        "synchrotron-top_up_start_countdown",
     )
     sim_run_engine.add_handler(
-        "read", "smargon-omega", lambda msg: {"smargon-omega": {"value": -1}}
+        "read", lambda msg: {"smargon-omega": {"value": -1}}, "smargon-omega"
     )
 
     msgs = sim_run_engine.simulate_plan(
@@ -294,18 +295,18 @@ def test_rotation_plan_reads_hardware(
         )
     )
 
-    msgs = sim_run_engine.assert_message_and_return_remaining(
+    msgs = assert_message_and_return_remaining(
         msgs,
         lambda msg: msg.command == "create"
         and msg.kwargs["name"] == CONST.DESCRIPTORS.HARDWARE_READ_PRE,
     )
     msgs_in_event = list(takewhile(lambda msg: msg.command != "save", msgs))
-    sim_run_engine.assert_message_and_return_remaining(
+    assert_message_and_return_remaining(
         msgs_in_event, lambda msg: msg.command == "read" and msg.obj.name == "smargon-x"
     )
-    sim_run_engine.assert_message_and_return_remaining(
+    assert_message_and_return_remaining(
         msgs_in_event, lambda msg: msg.command == "read" and msg.obj.name == "smargon-y"
     )
-    sim_run_engine.assert_message_and_return_remaining(
+    assert_message_and_return_remaining(
         msgs_in_event, lambda msg: msg.command == "read" and msg.obj.name == "smargon-z"
     )
diff --git a/tests/unit_tests/experiment_plans/test_set_energy_plan.py b/tests/unit_tests/experiment_plans/test_set_energy_plan.py
index 52eff1052..6d256c164 100644
--- a/tests/unit_tests/experiment_plans/test_set_energy_plan.py
+++ b/tests/unit_tests/experiment_plans/test_set_energy_plan.py
@@ -1,6 +1,7 @@
 from unittest.mock import patch
 
 import pytest
+from bluesky.simulators import assert_message_and_return_remaining
 from bluesky.utils import Msg
 from dodal.devices.xbpm_feedback import Pause
 
@@ -35,39 +36,39 @@ def test_set_energy(
     set_energy_composite,
 ):
     messages = sim_run_engine.simulate_plan(set_energy_plan(11.1, set_energy_composite))
-    messages = sim_run_engine.assert_message_and_return_remaining(
+    messages = assert_message_and_return_remaining(
         messages,
         lambda msg: msg.command == "set"
         and msg.obj.name == "xbpm_feedback-pause_feedback"
         and msg.args == (Pause.PAUSE,),
     )
-    messages = sim_run_engine.assert_message_and_return_remaining(
+    messages = assert_message_and_return_remaining(
         messages[1:],
         lambda msg: msg.command == "set"
         and msg.obj.name == "attenuator"
         and msg.args == (0.1,),
     )
-    messages = sim_run_engine.assert_message_and_return_remaining(
+    messages = assert_message_and_return_remaining(
         messages[1:],
         lambda msg: msg.command == "set"
         and msg.obj.name == "undulator_dcm"
         and msg.args == (11.1,)
         and msg.kwargs["group"] == "UNDULATOR_GROUP",
     )
-    messages = sim_run_engine.assert_message_and_return_remaining(
+    messages = assert_message_and_return_remaining(
         messages[1:], lambda msg: msg.command == "adjust_dcm_pitch_roll_vfm_from_lut"
     )
-    messages = sim_run_engine.assert_message_and_return_remaining(
+    messages = assert_message_and_return_remaining(
         messages[1:],
         lambda msg: msg.command == "wait" and msg.kwargs["group"] == "UNDULATOR_GROUP",
     )
-    messages = sim_run_engine.assert_message_and_return_remaining(
+    messages = assert_message_and_return_remaining(
         messages[1:],
         lambda msg: msg.command == "set"
         and msg.obj.name == "xbpm_feedback-pause_feedback"
         and msg.args == (Pause.RUN,),
     )
-    messages = sim_run_engine.assert_message_and_return_remaining(
+    messages = assert_message_and_return_remaining(
         messages[1:],
         lambda msg: msg.command == "set"
         and msg.obj.name == "attenuator"
diff --git a/tests/unit_tests/experiment_plans/test_wait_for_robot_load_then_centre.py b/tests/unit_tests/experiment_plans/test_wait_for_robot_load_then_centre.py
index 93884b968..c1e52ec2d 100644
--- a/tests/unit_tests/experiment_plans/test_wait_for_robot_load_then_centre.py
+++ b/tests/unit_tests/experiment_plans/test_wait_for_robot_load_then_centre.py
@@ -3,6 +3,7 @@
 
 import pytest
 from bluesky.run_engine import RunEngine
+from bluesky.simulators import RunEngineSimulator, assert_message_and_return_remaining
 from bluesky.utils import Msg
 from dodal.devices.aperturescatterguard import AperturePositions
 from dodal.devices.eiger import EigerDetector
@@ -98,17 +99,17 @@ def test_when_plan_run_with_requested_energy_specified_energy_change_executes(
     mock_centring_plan: MagicMock,
     robot_load_composite: RobotLoadThenCentreComposite,
     robot_load_then_centre_params: RobotLoadThenCentre,
-    sim_run_engine,
+    sim_run_engine: RunEngineSimulator,
 ):
     sim_run_engine.add_handler(
         "read",
-        "dcm-energy_in_kev",
         lambda msg: {"dcm-energy_in_kev": {"value": 11.105}},
+        "dcm-energy_in_kev",
     )
     messages = sim_run_engine.simulate_plan(
         robot_load_then_centre(robot_load_composite, robot_load_then_centre_params)
     )
-    sim_run_engine.assert_message_and_return_remaining(
+    assert_message_and_return_remaining(
         messages, lambda msg: msg.command == "set_energy_plan"
     )
     params_passed: PinTipCentreThenXrayCentre = mock_centring_plan.call_args[0][1]
@@ -126,12 +127,12 @@ def test_when_plan_run_with_requested_energy_specified_energy_change_executes(
 def test_robot_load_then_centre_doesnt_set_energy_if_not_specified_and_current_energy_set_on_eiger(
     robot_load_composite: RobotLoadThenCentreComposite,
     robot_load_then_centre_params_no_energy: RobotLoadThenCentre,
-    sim_run_engine,
+    sim_run_engine: RunEngineSimulator,
 ):
     sim_run_engine.add_handler(
         "read",
-        "dcm-energy_in_kev",
         lambda msg: {"dcm-energy_in_kev": {"value": 11.105}},
+        "dcm-energy_in_kev",
     )
     messages = sim_run_engine.simulate_plan(
         robot_load_then_centre(
@@ -148,7 +149,7 @@ def run_simulating_smargon_wait(
     robot_load_then_centre_params,
     robot_load_composite,
     total_disabled_reads,
-    sim_run_engine,
+    sim_run_engine: RunEngineSimulator,
 ):
     robot_load_composite.smargon = instantiate_fake_device(Smargon, name="smargon")
     robot_load_composite.eiger = instantiate_fake_device(EigerDetector, name="eiger")
@@ -162,13 +163,11 @@ def return_not_disabled_after_reads(_):
 
     sim_run_engine.add_handler(
         "read",
-        "dcm-energy_in_kev",
         lambda msg: {"dcm-energy_in_kev": {"value": 11.105}},
+        "dcm-energy_in_kev",
     )
     sim_run_engine.add_handler(
-        "read",
-        "smargon-disabled",
-        return_not_disabled_after_reads,
+        "read", return_not_disabled_after_reads, "smargon-disabled"
     )
 
     return sim_run_engine.simulate_plan(
@@ -367,14 +366,14 @@ def test_when_plan_run_then_thawing_turned_on_for_expected_time(
     mock_centring_plan: MagicMock,
     robot_load_composite: RobotLoadThenCentreComposite,
     robot_load_then_centre_params_no_energy: RobotLoadThenCentre,
-    sim_run_engine,
+    sim_run_engine: RunEngineSimulator,
 ):
     robot_load_then_centre_params_no_energy.thawing_time = (thaw_time := 50)
 
     sim_run_engine.add_handler(
         "read",
-        "dcm-energy_in_kev",
         lambda msg: {"dcm-energy_in_kev": {"value": 11.105}},
+        "dcm-energy_in_kev",
     )
 
     messages = sim_run_engine.simulate_plan(
@@ -384,7 +383,7 @@ def test_when_plan_run_then_thawing_turned_on_for_expected_time(
         )
     )
 
-    sim_run_engine.assert_message_and_return_remaining(
+    assert_message_and_return_remaining(
         messages,
         lambda msg: msg.command == "set"
         and msg.obj.name == "thawer-thaw_for_time_s"
diff --git a/tests/unit_tests/external_interaction/callbacks/rotation/test_ispyb_callback.py b/tests/unit_tests/external_interaction/callbacks/rotation/test_ispyb_callback.py
index da764f44d..cd9c99703 100644
--- a/tests/unit_tests/external_interaction/callbacks/rotation/test_ispyb_callback.py
+++ b/tests/unit_tests/external_interaction/callbacks/rotation/test_ispyb_callback.py
@@ -218,9 +218,7 @@ def test_oav_rotation_snapshot_triggered_event(
     mock_ispyb_conn, dummy_rotation_params, rotation_start_outer_doc_without_snapshots
 ):
     callback = RotationISPyBCallback()
-    callback.activity_gated_start(
-        rotation_start_outer_doc_without_snapshots
-    )  # pyright: ignore
+    callback.activity_gated_start(rotation_start_outer_doc_without_snapshots)  # pyright: ignore
     callback.activity_gated_start(
         TestData.test_rotation_start_main_document  # pyright: ignore
     )
@@ -301,9 +299,9 @@ def test_comment_correct_after_hardware_read(
 ):
     callback = RotationISPyBCallback()
     test_rotation_start_outer_document["hyperion_parameters"] = (
-        test_rotation_start_outer_document["hyperion_parameters"].replace(
-            '"comment": "test"', '"comment": "a lovely unit test"'
-        )
+        test_rotation_start_outer_document[
+            "hyperion_parameters"
+        ].replace('"comment": "test"', '"comment": "a lovely unit test"')
     )
     callback.activity_gated_start(test_rotation_start_outer_document)  # pyright: ignore
     callback.activity_gated_start(
diff --git a/tests/unit_tests/external_interaction/callbacks/xray_centre/test_ispyb_callback.py b/tests/unit_tests/external_interaction/callbacks/xray_centre/test_ispyb_callback.py
index 9c1fcdd7f..5328e2c24 100644
--- a/tests/unit_tests/external_interaction/callbacks/xray_centre/test_ispyb_callback.py
+++ b/tests/unit_tests/external_interaction/callbacks/xray_centre/test_ispyb_callback.py
@@ -51,9 +51,7 @@
 class TestXrayCentreISPyBCallback:
     def test_activity_gated_start_3d(self, mock_ispyb_conn):
         callback = GridscanISPyBCallback()
-        callback.activity_gated_start(
-            TestData.test_gridscan3d_start_document
-        )  # pyright: ignore
+        callback.activity_gated_start(TestData.test_gridscan3d_start_document)  # pyright: ignore
         mx_acq = mx_acquisition_from_conn(mock_ispyb_conn)
         assert_upsert_call_with(
             mx_acq.upsert_data_collection_group.mock_calls[0],  # pyright: ignore
@@ -79,9 +77,7 @@ def test_activity_gated_start_3d(self, mock_ispyb_conn):
 
     def test_hardware_read_event_3d(self, mock_ispyb_conn):
         callback = GridscanISPyBCallback()
-        callback.activity_gated_start(
-            TestData.test_gridscan3d_start_document
-        )  # pyright: ignore
+        callback.activity_gated_start(TestData.test_gridscan3d_start_document)  # pyright: ignore
         mx_acq = mx_acquisition_from_conn(mock_ispyb_conn)
         mx_acq.upsert_data_collection_group.reset_mock()
         mx_acq.upsert_data_collection.reset_mock()
@@ -117,9 +113,7 @@ def test_hardware_read_event_3d(self, mock_ispyb_conn):
 
     def test_flux_read_events_3d(self, mock_ispyb_conn):
         callback = GridscanISPyBCallback()
-        callback.activity_gated_start(
-            TestData.test_gridscan3d_start_document
-        )  # pyright: ignore
+        callback.activity_gated_start(TestData.test_gridscan3d_start_document)  # pyright: ignore
         mx_acq = mx_acquisition_from_conn(mock_ispyb_conn)
         callback.activity_gated_descriptor(
             TestData.test_descriptor_document_pre_data_collection
@@ -172,9 +166,7 @@ def test_flux_read_events_3d(self, mock_ispyb_conn):
 
     def test_activity_gated_event_oav_snapshot_triggered(self, mock_ispyb_conn):
         callback = GridscanISPyBCallback()
-        callback.activity_gated_start(
-            TestData.test_gridscan3d_start_document
-        )  # pyright: ignore
+        callback.activity_gated_start(TestData.test_gridscan3d_start_document)  # pyright: ignore
         mx_acq = mx_acquisition_from_conn(mock_ispyb_conn)
         mx_acq.upsert_data_collection_group.reset_mock()
         mx_acq.upsert_data_collection.reset_mock()
diff --git a/tests/unit_tests/external_interaction/callbacks/xray_centre/test_ispyb_handler.py b/tests/unit_tests/external_interaction/callbacks/xray_centre/test_ispyb_handler.py
index e8d8713ed..0a90ae894 100644
--- a/tests/unit_tests/external_interaction/callbacks/xray_centre/test_ispyb_handler.py
+++ b/tests/unit_tests/external_interaction/callbacks/xray_centre/test_ispyb_handler.py
@@ -167,9 +167,7 @@ def test_given_fgs_plan_finished_when_zocalo_results_event_then_expected_comment
     ):
         ispyb_handler = GridscanISPyBCallback()
 
-        ispyb_handler.activity_gated_start(
-            td.test_gridscan3d_start_document
-        )  # type:ignore
+        ispyb_handler.activity_gated_start(td.test_gridscan3d_start_document)  # type:ignore
 
         ispyb_handler.activity_gated_start(td.test_do_fgs_start_document)  # type:ignore
         ispyb_handler.activity_gated_stop(td.test_do_fgs_gridscan_stop_document)
diff --git a/tests/unit_tests/external_interaction/callbacks/xray_centre/test_ispyb_mapping.py b/tests/unit_tests/external_interaction/callbacks/xray_centre/test_ispyb_mapping.py
index 0a273043e..36bc3ebe1 100644
--- a/tests/unit_tests/external_interaction/callbacks/xray_centre/test_ispyb_mapping.py
+++ b/tests/unit_tests/external_interaction/callbacks/xray_centre/test_ispyb_mapping.py
@@ -28,22 +28,25 @@ def test_ispyb_deposition_rounds_position_to_int(
     mock_ispyb_conn: MagicMock,
     dummy_params,
 ):
-    assert construct_comment_for_gridscan(
-        DataCollectionGridInfo(
-            0.1,
-            0.1,
-            40,
-            20,
-            1.25,
-            1.25,
-            0.01,  # type: ignore
-            100,
-            Orientation.HORIZONTAL,
-            True,  # type: ignore
-        ),
-    ) == (
-        "Hyperion: Xray centring - Diffraction grid scan of 40 by 20 images "
-        "in 100.0 um by 100.0 um steps. Top left (px): [0,100], bottom right (px): [3200,1700]."
+    assert (
+        construct_comment_for_gridscan(
+            DataCollectionGridInfo(
+                0.1,
+                0.1,
+                40,
+                20,
+                1.25,
+                1.25,
+                0.01,  # type: ignore
+                100,
+                Orientation.HORIZONTAL,
+                True,  # type: ignore
+            ),
+        )
+        == (
+            "Hyperion: Xray centring - Diffraction grid scan of 40 by 20 images "
+            "in 100.0 um by 100.0 um steps. Top left (px): [0,100], bottom right (px): [3200,1700]."
+        )
     )
 
 
diff --git a/tests/unit_tests/external_interaction/ispyb/test_rotation_ispyb_store.py b/tests/unit_tests/external_interaction/ispyb/test_rotation_ispyb_store.py
index 5f4751482..bd75916d2 100644
--- a/tests/unit_tests/external_interaction/ispyb/test_rotation_ispyb_store.py
+++ b/tests/unit_tests/external_interaction/ispyb/test_rotation_ispyb_store.py
@@ -482,9 +482,7 @@ def test_store_rotation_scan_uses_supplied_dcgid(
     scan_data_info_for_begin,
     scan_data_info_for_update,
 ):
-    mock_ispyb_conn.return_value.mx_acquisition.upsert_data_collection_group.return_value = (
-        dcgid
-    )
+    mock_ispyb_conn.return_value.mx_acquisition.upsert_data_collection_group.return_value = dcgid
     store_in_ispyb = StoreInIspyb(CONST.SIM.ISPYB_CONFIG)
     scan_data_info_for_begin.data_collection_info.parent_id = dcgid
     ispyb_ids = store_in_ispyb.begin_deposition(