fixed a bug in the metadata_fields and value_fields

src/ophyd_async/epics/_backend/_p4p.py

@@ -153,6 +153,18 @@ def value(self, value: Value):
     def descriptor(self, source: str, value) -> Descriptor:
         raise NotImplementedError("Describing Dict signals not currently supported")
 
+    def metadata_fields(self) -> List[str]:
+        """
+        Fields to request from PVA for metadata.
+        """
+        return []
+
+    def value_fields(self) -> List[str]:
+        """
+        Fields to request from PVA for the value.
+        """
+        return []
+
 
 class DisconnectedPvaConverter(PvaConverter):
     def __getattribute__(self, __name: str) -> Any:

tests/epics/test_signals.py

@@ -27,7 +27,6 @@
 import pytest
 from aioca import CANothing, purge_channel_caches
 from bluesky.protocols import Reading
-
 from ophyd_async.core import SignalBackend, T, get_dtype, load_from_yaml, save_to_yaml
 from ophyd_async.core.utils import NotConnected
 from ophyd_async.epics.signal._epics_transport import EpicsTransport
@@ -398,6 +397,7 @@ async def test_pvi_structure(ioc: IOC) -> None:
             await backend.get_descriptor()
         # Check initial value
         await q.assert_updates(expected)
+        await backend.get_value()
 
     finally:
         q.close()