diff --git a/src/ophyd_async/core/_detector.py b/src/ophyd_async/core/_detector.py
index f596e6351e..b2cc788ed2 100644
--- a/src/ophyd_async/core/_detector.py
+++ b/src/ophyd_async/core/_detector.py
@@ -312,9 +312,9 @@ async def prepare(self, value: TriggerInfo) -> None:
             value: TriggerInfo describing how to trigger the detector
         """
         if value.trigger != DetectorTrigger.INTERNAL:
-            assert (
-                value.deadtime
-            ), "Deadtime must be supplied when in externally triggered mode"
+            assert value.deadtime, (
+                "Deadtime must be supplied when in externally triggered mode"
+            )
         if value.deadtime:
             required = self._controller.get_deadtime(value.livetime)
             assert required <= value.deadtime, (
diff --git a/src/ophyd_async/core/_device.py b/src/ophyd_async/core/_device.py
index 8f12607591..eee5b8b339 100644
--- a/src/ophyd_async/core/_device.py
+++ b/src/ophyd_async/core/_device.py
@@ -275,9 +275,10 @@ def _caller_locals(self) -> dict[str, Any]:
             caller_frame = tb.tb_frame
             while caller_frame.f_locals.get("self", None) is self:
                 caller_frame = caller_frame.f_back
-                assert (
-                    caller_frame
-                ), "No previous frame to the one with self in it, this shouldn't happen"
+                assert caller_frame, (
+                    "No previous frame to the one with self in it, "
+                    "this shouldn't happen"
+                )
             return caller_frame.f_locals.copy()
 
     def __enter__(self) -> DeviceProcessor:
diff --git a/src/ophyd_async/core/_device_filler.py b/src/ophyd_async/core/_device_filler.py
index dfca58981f..754275fd98 100644
--- a/src/ophyd_async/core/_device_filler.py
+++ b/src/ophyd_async/core/_device_filler.py
@@ -254,9 +254,9 @@ def fill_child_device(
             # We need to add a new entry to a DeviceVector
             vector = self._ensure_device_vector(name)
             vector_device_type = self._vector_device_type[name] or device_type
-            assert issubclass(
-                vector_device_type, Device
-            ), f"{vector_device_type} is not a Device"
+            assert issubclass(vector_device_type, Device), (
+                f"{vector_device_type} is not a Device"
+            )
             connector = self._device_connector_factory()
             vector[vector_index] = vector_device_type(connector=connector)
         elif child := getattr(self._device, name, None):
diff --git a/src/ophyd_async/core/_utils.py b/src/ophyd_async/core/_utils.py
index e89131ea75..16368204a3 100644
--- a/src/ophyd_async/core/_utils.py
+++ b/src/ophyd_async/core/_utils.py
@@ -94,7 +94,7 @@ def _format_sub_errors(self, name: str, error: Exception, indent="") -> str:
     def format_error_string(self, indent="") -> str:
         if not isinstance(self._errors, dict) and not isinstance(self._errors, str):
             raise RuntimeError(
-                f"Unexpected type `{type(self._errors)}` " "expected `str` or `dict`"
+                f"Unexpected type `{type(self._errors)}` expected `str` or `dict`"
             )
 
         if isinstance(self._errors, str):
diff --git a/src/ophyd_async/epics/adaravis/_aravis_controller.py b/src/ophyd_async/epics/adaravis/_aravis_controller.py
index e78fdf21aa..b42463a9a3 100644
--- a/src/ophyd_async/epics/adaravis/_aravis_controller.py
+++ b/src/ophyd_async/epics/adaravis/_aravis_controller.py
@@ -36,7 +36,7 @@ async def prepare(self, trigger_info: TriggerInfo):
         else:
             image_mode = adcore.ImageMode.MULTIPLE
         if (exposure := trigger_info.livetime) is not None:
-            asyncio.gather(self.driver.acquire_time.set(exposure))
+            await self.driver.acquire_time.set(exposure)
 
         trigger_mode, trigger_source = self._get_trigger_info(trigger_info.trigger)
         # trigger mode must be set first and on it's own!
diff --git a/src/ophyd_async/epics/adcore/_core_logic.py b/src/ophyd_async/epics/adcore/_core_logic.py
index a0da204374..b35a1b962e 100644
--- a/src/ophyd_async/epics/adcore/_core_logic.py
+++ b/src/ophyd_async/epics/adcore/_core_logic.py
@@ -35,9 +35,9 @@ def __init__(
         self._arm_status: AsyncStatus | None = None
 
     async def prepare(self, trigger_info: TriggerInfo) -> None:
-        assert (
-            trigger_info.trigger == DetectorTrigger.INTERNAL
-        ), "fly scanning (i.e. external triggering) is not supported for this device"
+        assert trigger_info.trigger == DetectorTrigger.INTERNAL, (
+            "fly scanning (i.e. external triggering) is not supported for this device"
+        )
         self.frame_timeout = (
             DEFAULT_TIMEOUT + await self.driver.acquire_time.get_value()
         )
diff --git a/src/ophyd_async/epics/adcore/_core_writer.py b/src/ophyd_async/epics/adcore/_core_writer.py
index 4102778b6f..0c131677a4 100644
--- a/src/ophyd_async/epics/adcore/_core_writer.py
+++ b/src/ophyd_async/epics/adcore/_core_writer.py
@@ -112,9 +112,9 @@ async def begin_capture(self) -> None:
             self.fileio.file_number.set(0),
         )
 
-        assert (
-            await self.fileio.file_path_exists.get_value()
-        ), f"File path {info.directory_path} for file plugin does not exist!"
+        assert await self.fileio.file_path_exists.get_value(), (
+            f"File path {info.directory_path} for file plugin does not exist!"
+        )
 
         # Overwrite num_capture to go forever
         await self.fileio.num_capture.set(0)
diff --git a/src/ophyd_async/epics/core/_aioca.py b/src/ophyd_async/epics/core/_aioca.py
index ff2fff15b5..44f0d1e5e8 100644
--- a/src/ophyd_async/epics/core/_aioca.py
+++ b/src/ophyd_async/epics/core/_aioca.py
@@ -322,9 +322,9 @@ async def get_setpoint(self) -> SignalDatatypeT:
 
     def set_callback(self, callback: Callback[Reading[SignalDatatypeT]] | None) -> None:
         if callback:
-            assert (
-                not self.subscription
-            ), "Cannot set a callback when one is already set"
+            assert not self.subscription, (
+                "Cannot set a callback when one is already set"
+            )
             self.subscription = camonitor(
                 self.read_pv,
                 lambda v: callback(self._make_reading(v)),
diff --git a/src/ophyd_async/epics/core/_p4p.py b/src/ophyd_async/epics/core/_p4p.py
index 1f5c3acbe6..73fc919cb8 100644
--- a/src/ophyd_async/epics/core/_p4p.py
+++ b/src/ophyd_async/epics/core/_p4p.py
@@ -404,9 +404,9 @@ async def get_setpoint(self) -> SignalDatatypeT:
 
     def set_callback(self, callback: Callback[Reading[SignalDatatypeT]] | None) -> None:
         if callback:
-            assert (
-                not self.subscription
-            ), "Cannot set a callback when one is already set"
+            assert not self.subscription, (
+                "Cannot set a callback when one is already set"
+            )
 
             async def async_callback(v):
                 callback(self._make_reading(v))
diff --git a/src/ophyd_async/epics/motor.py b/src/ophyd_async/epics/motor.py
index c512f4ba03..2ffd69cde2 100644
--- a/src/ophyd_async/epics/motor.py
+++ b/src/ophyd_async/epics/motor.py
@@ -125,9 +125,9 @@ async def prepare(self, value: FlyMotorInfo):
     @AsyncStatus.wrap
     async def kickoff(self):
         """Begin moving motor from prepared position to final position."""
-        assert (
-            self._fly_completed_position
-        ), "Motor must be prepared before attempting to kickoff"
+        assert self._fly_completed_position, (
+            "Motor must be prepared before attempting to kickoff"
+        )
 
         self._fly_status = self.set(
             self._fly_completed_position, timeout=self._fly_timeout
diff --git a/src/ophyd_async/sim/_pattern_detector/_pattern_generator.py b/src/ophyd_async/sim/_pattern_detector/_pattern_generator.py
index 01c54c8245..d2882726e9 100644
--- a/src/ophyd_async/sim/_pattern_detector/_pattern_generator.py
+++ b/src/ophyd_async/sim/_pattern_detector/_pattern_generator.py
@@ -69,9 +69,9 @@ def write_data_to_dataset(self, path: str, data_shape: tuple[int, ...], data):
         """Write data to named dataset, resizing to fit and flushing after."""
         assert self._handle_for_h5_file, "no file has been opened!"
         dset = self._handle_for_h5_file[path]
-        assert isinstance(
-            dset, h5py.Dataset
-        ), f"Expected {path} to be dataset, got {dset}"
+        assert isinstance(dset, h5py.Dataset), (
+            f"Expected {path} to be dataset, got {dset}"
+        )
         dset.resize((self.image_counter + 1,) + data_shape)
         dset[self.image_counter] = data
         dset.flush()
diff --git a/src/ophyd_async/tango/core/_tango_transport.py b/src/ophyd_async/tango/core/_tango_transport.py
index 77394905f6..32c197a6ea 100644
--- a/src/ophyd_async/tango/core/_tango_transport.py
+++ b/src/ophyd_async/tango/core/_tango_transport.py
@@ -210,11 +210,11 @@ async def wait_for_reply(rd: int, to: float | None):
                             await asyncio.sleep(A_BIT)
                             if to and (time.time() - start_time > to):
                                 raise TimeoutError(
-                                    f"{self._name} attr put failed:" f" Timeout"
+                                    f"{self._name} attr put failed: Timeout"
                                 ) from exc
                         else:
                             raise RuntimeError(
-                                f"{self._name} device failure:" f" {exc.args[0].desc}"
+                                f"{self._name} device failure: {exc.args[0].desc}"
                             ) from exc
 
             return AsyncStatus(wait_for_reply(rid, timeout))
@@ -422,7 +422,7 @@ async def _put():
                 raise TimeoutError(f"{self._name} command failed: Timeout") from te
             except DevFailed as de:
                 raise RuntimeError(
-                    f"{self._name} device" f" failure: {de.args[0].desc}"
+                    f"{self._name} device failure: {de.args[0].desc}"
                 ) from de
 
         else:
@@ -446,8 +446,7 @@ async def wait_for_reply(rd: int, to: float | None):
                                 ) from de_exc
                         else:
                             raise RuntimeError(
-                                f"{self._name} device failure:"
-                                f" {de_exc.args[0].desc}"
+                                f"{self._name} device failure: {de_exc.args[0].desc}"
                             ) from de_exc
 
             return AsyncStatus(wait_for_reply(rid, timeout))
@@ -739,11 +738,11 @@ def set_callback(self, callback: Callback | None) -> None:
                 self.proxies[self.read_trl].subscribe_callback(callback)  # type: ignore
             except AssertionError as ae:
                 raise RuntimeError(
-                    "Cannot set a callback when one" " is already set"
+                    "Cannot set a callback when one is already set"
                 ) from ae
             except RuntimeError as exc:
                 raise RuntimeError(
-                    f"Cannot set callback" f" for {self.read_trl}. {exc}"
+                    f"Cannot set callback for {self.read_trl}. {exc}"
                 ) from exc
 
         else:
diff --git a/src/ophyd_async/testing/_assert.py b/src/ophyd_async/testing/_assert.py
index 48d8a35538..7b1623127b 100644
--- a/src/ophyd_async/testing/_assert.py
+++ b/src/ophyd_async/testing/_assert.py
@@ -79,12 +79,12 @@ async def assert_reading(
 
     """
     actual_reading = await readable.read()
-    assert (
-        _approx_readable_value(expected_reading) == actual_reading
-    ), _generate_assert_error_msg(
-        name=readable.name,
-        expected_result=expected_reading,
-        actual_result=actual_reading,
+    assert _approx_readable_value(expected_reading) == actual_reading, (
+        _generate_assert_error_msg(
+            name=readable.name,
+            expected_result=expected_reading,
+            actual_result=actual_reading,
+        )
     )
 
 
@@ -109,12 +109,12 @@ async def assert_configuration(
 
     """
     actual_configurable = await configurable.read_configuration()
-    assert (
-        _approx_readable_value(configuration) == actual_configurable
-    ), _generate_assert_error_msg(
-        name=configurable.name,
-        expected_result=configuration,
-        actual_result=actual_configurable,
+    assert _approx_readable_value(configuration) == actual_configurable, (
+        _generate_assert_error_msg(
+            name=configurable.name,
+            expected_result=configuration,
+            actual_result=actual_configurable,
+        )
     )
 
 
diff --git a/src/ophyd_async/testing/_mock_signal_utils.py b/src/ophyd_async/testing/_mock_signal_utils.py
index 683666e6b4..b5077b637c 100644
--- a/src/ophyd_async/testing/_mock_signal_utils.py
+++ b/src/ophyd_async/testing/_mock_signal_utils.py
@@ -22,9 +22,9 @@ def get_mock(device: Device | Signal) -> Mock:
 def _get_mock_signal_backend(signal: Signal) -> MockSignalBackend:
     connector = signal._connector  # noqa: SLF001
     assert isinstance(connector, SignalConnector), f"Expected Signal, got {signal}"
-    assert isinstance(
-        connector.backend, MockSignalBackend
-    ), f"Signal {signal} not connected in mock mode"
+    assert isinstance(connector.backend, MockSignalBackend), (
+        f"Signal {signal} not connected in mock mode"
+    )
     return connector.backend
 
 
diff --git a/tests/conftest.py b/tests/conftest.py
index 69d4cfdf4f..bd90848e06 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -93,6 +93,7 @@ def _error_and_kill_pending_tasks(
         task
         for task in asyncio.all_tasks(loop)
         if (coro := task.get_coro()) is not None
+        and hasattr(coro, "__name__")
         and coro.__name__ not in _ALLOWED_PYTEST_TASKS
         and not task.done()
     }
@@ -112,7 +113,7 @@ def _error_and_kill_pending_tasks(
 
 
 @pytest.fixture(autouse=True, scope="function")
-def fail_test_on_unclosed_tasks(request: FixtureRequest):
+async def fail_test_on_unclosed_tasks(request: FixtureRequest):
     """
     Used on every test to ensure failure if there are pending tasks
     by the end of the test.
diff --git a/tests/core/test_mock_signal_backend.py b/tests/core/test_mock_signal_backend.py
index 8370e7340f..482cd6d769 100644
--- a/tests/core/test_mock_signal_backend.py
+++ b/tests/core/test_mock_signal_backend.py
@@ -320,9 +320,7 @@ async def test_reset_mock_put_calls(mock_signals):
     # Replacing spaces because they change between runners
     # (e.g the github actions runner has more)
     assert str(exc.value).replace(" ", "").replace("\n", "") == (
-        "expectedcallnotfound."
-        "Expected:put('test_value',wait=<ANY>)"
-        "Actual:notcalled."
+        "expectedcallnotfound.Expected:put('test_value',wait=<ANY>)Actual:notcalled."
     )
 
 
diff --git a/tests/core/test_utils.py b/tests/core/test_utils.py
index 7a1f07a2a9..76d334f7f4 100644
--- a/tests/core/test_utils.py
+++ b/tests/core/test_utils.py
@@ -284,7 +284,7 @@ async def test_combining_top_level_signal_and_child_device():
 async def test_format_error_string_input():
     with pytest.raises(
         RuntimeError,
-        match=("Unexpected type `<class 'int'>` " "expected `str` or `dict`"),
+        match=("Unexpected type `<class 'int'>` expected `str` or `dict`"),
     ):
         not_connected = NotConnected(123)
         str(not_connected)
diff --git a/tests/epics/adaravis/test_aravis.py b/tests/epics/adaravis/test_aravis.py
index 6382306d23..fd83f5d45e 100644
--- a/tests/epics/adaravis/test_aravis.py
+++ b/tests/epics/adaravis/test_aravis.py
@@ -1,4 +1,5 @@
 from typing import cast
+from unittest.mock import AsyncMock, patch
 
 import pytest
 
@@ -133,17 +134,24 @@ async def test_can_decribe_collect(
 
 
 async def test_unsupported_trigger_excepts(test_adaravis: adaravis.AravisDetector):
-    with pytest.raises(
-        ValueError,
-        # str(EnumClass.value) handling changed in Python 3.11
-        match=r"AravisController only supports the following trigger types: .* but",
-    ):
-        await test_adaravis.prepare(
-            TriggerInfo(
-                number_of_triggers=0,
-                trigger=DetectorTrigger.VARIABLE_GATE,
-                deadtime=1,
-                livetime=1,
-                frame_timeout=3,
+    with patch(
+        "ophyd_async.epics.adcore._hdf_writer.ADHDFWriter.open", new_callable=AsyncMock
+    ) as mock_open:
+        with pytest.raises(
+            ValueError,
+            # str(EnumClass.value) handling changed in Python 3.11
+            match=(
+                "AravisController only supports the following trigger types: .* but"
+            ),
+        ):
+            await test_adaravis.prepare(
+                TriggerInfo(
+                    number_of_triggers=0,
+                    trigger=DetectorTrigger.VARIABLE_GATE,
+                    deadtime=1,
+                    livetime=1,
+                    frame_timeout=3,
+                )
             )
-        )
+
+    mock_open.assert_called_once()
diff --git a/tests/epics/adpilatus/test_pilatus.py b/tests/epics/adpilatus/test_pilatus.py
index e5c8613e03..a1f3bbc5ef 100644
--- a/tests/epics/adpilatus/test_pilatus.py
+++ b/tests/epics/adpilatus/test_pilatus.py
@@ -1,7 +1,7 @@
 import asyncio
 from collections.abc import Awaitable, Callable
 from typing import cast
-from unittest.mock import patch
+from unittest.mock import AsyncMock, patch
 
 import pytest
 
@@ -103,19 +103,24 @@ async def test_hints_from_hdf_writer(test_adpilatus: adpilatus.PilatusDetector):
 
 
 async def test_unsupported_trigger_excepts(test_adpilatus: adpilatus.PilatusDetector):
-    with pytest.raises(
-        ValueError,
-        # str(EnumClass.value) handling changed in Python 3.11
-        match=r"PilatusController only supports the following trigger types: .* but",
-    ):
-        await test_adpilatus.prepare(
-            TriggerInfo(
-                number_of_triggers=1,
-                trigger=DetectorTrigger.EDGE_TRIGGER,
-                deadtime=1.0,
-                livetime=1.0,
+    open = "ophyd_async.epics.adcore._hdf_writer.ADHDFWriter.open"
+    with patch(open, new_callable=AsyncMock) as mock_open:
+        with pytest.raises(
+            ValueError,
+            # str(EnumClass.value) handling changed in Python 3.11
+            match=(
+                "PilatusController only supports the following trigger types: .* but"
+            ),
+        ):
+            await test_adpilatus.prepare(
+                TriggerInfo(
+                    number_of_triggers=1,
+                    trigger=DetectorTrigger.EDGE_TRIGGER,
+                    deadtime=1.0,
+                    livetime=1.0,
+                )
             )
-        )
+    mock_open.assert_called_once()
 
 
 async def test_exposure_time_and_acquire_period_set(
diff --git a/tests/epics/signal/test_signals.py b/tests/epics/signal/test_signals.py
index e7fa6c3cbf..fdb7f44a76 100644
--- a/tests/epics/signal/test_signals.py
+++ b/tests/epics/signal/test_signals.py
@@ -623,7 +623,7 @@ async def test_signals_created_for_not_prec_0_float_cannot_use_int(
     sig = epics_signal_rw(int, ioc_devices.get_pv(protocol, "float_prec_1"))
     with pytest.raises(
         TypeError,
-        match="float_prec_1 with inferred datatype float" ".* cannot be coerced to int",
+        match="float_prec_1 with inferred datatype float.* cannot be coerced to int",
     ):
         await sig.connect()
 
diff --git a/tests/sim/test_sim_detector.py b/tests/sim/test_sim_detector.py
index 3f2e0f3557..46dd8f94c4 100644
--- a/tests/sim/test_sim_detector.py
+++ b/tests/sim/test_sim_detector.py
@@ -14,9 +14,9 @@
 async def test_sim_pattern_detector_initialization(
     sim_pattern_detector: PatternDetector,
 ):
-    assert (
-        sim_pattern_detector.pattern_generator
-    ), "PatternGenerator was not initialized correctly."
+    assert sim_pattern_detector.pattern_generator, (
+        "PatternGenerator was not initialized correctly."
+    )
 
 
 async def test_detector_creates_controller_and_writer(