Call sync setpoint callbacks with validated value

src/fastcs/attributes/attr_r.py

@@ -73,13 +73,13 @@ async def update(self, value: Any) -> None:
             ValueError: If the value fails to be validated to DType_T
 
         """
-        self.log_event(
-            "Attribute set", value=value, value_type=type(value), attribute=self
-        )
+        self.log_event("Attribute set", value=repr(value), attribute=self)
 
         _previous_value = self._value
         self._value = self._datatype.validate(value)
 
+        self.log_event("Value validated", value=repr(self._value), attribute=self)
+
         self._on_update_events -= {
             e for e in self._on_update_events if e.set(self._value)
         }
@@ -94,7 +94,7 @@ async def update(self, value: Any) -> None:
                 await asyncio.gather(*[cb(self._value) for cb in callbacks_to_call])
             except Exception as e:
                 logger.opt(exception=e).error(
-                    "On update callbacks failed", attribute=self, value=value
+                    "On update callbacks failed", attribute=self, value=repr(value)
                 )
                 raise
 

src/fastcs/attributes/attr_rw.py

@@ -41,5 +41,5 @@ async def update(self, value: DType_T):
         await super().update(value)
 
         if not self._setpoint_initialised:
-            await self._call_sync_setpoint_callbacks(value)
+            await self._call_sync_setpoint_callbacks(self._value)
             self._setpoint_initialised = True

src/fastcs/transports/epics/ca/ioc.py

@@ -171,7 +171,9 @@ def _create_and_link_read_pv(
     pv = f"{pv_prefix}:{pv_name}"
 
     async def async_record_set(value: DType_T):
-        tracer.log_event("PV set from attribute", topic=attribute, pv=pv, value=value)
+        tracer.log_event(
+            "PV set from attribute", topic=attribute, pv=pv, value=repr(value)
+        )
 
         record.set(cast_to_epics_type(attribute.datatype, value))
 
@@ -217,13 +219,13 @@ def _create_and_link_write_pv(
     pv = f"{pv_prefix}:{pv_name}"
 
     async def on_update(value):
-        logger.info("PV put: {pv} = {value}", pv=pv, value=value)
+        logger.info("PV put: {pv} = {value}", pv=pv, value=repr(value))
 
         await attribute.put(cast_from_epics_type(attribute.datatype, value))
 
     async def set_setpoint_without_process(value: DType_T):
         tracer.log_event(
-            "PV setpoint set from attribute", topic=attribute, pv=pv, value=value
+            "PV setpoint set from attribute", topic=attribute, pv=pv, value=repr(value)
         )
 
         record.set(cast_to_epics_type(attribute.datatype, value), process=False)

src/fastcs/transports/epics/ca/util.py

@@ -146,7 +146,7 @@ def cast_to_epics_type(datatype: DataType[DType_T], value: DType_T) -> Any:
             else:  # enum backed by string record
                 return datatype.validate(value).name
         case String() as string:
-            return value[: string.length]
+            return value[: string.length or DEFAULT_STRING_WAVEFORM_LENGTH]
         case datatype if issubclass(type(datatype), EPICS_ALLOWED_DATATYPES):
             return value
         case _:

tests/test_attributes.py

@@ -50,6 +50,33 @@ def test_attr_r():
     assert attr.get() == ""
 
 
+@pytest.mark.asyncio
+async def test_attr_update(mocker: MockerFixture):
+    attr = AttrRW(Int())
+
+    await attr.update(42)
+    assert attr.get() == 42
+
+    await attr.update("100")  # type: ignore
+    assert attr.get() == 100
+
+    with pytest.raises(ValueError, match="Failed to cast"):
+        await attr.update("not_an_int")  # type: ignore
+
+    attr = AttrRW(Int())
+    sync_setpoint_mock = mocker.AsyncMock()
+    attr.add_sync_setpoint_callback(sync_setpoint_mock)
+
+    await attr.update("200")  # type: ignore
+    assert attr.get() == 200
+    sync_setpoint_mock.assert_called_once_with(200)
+
+    sync_setpoint_mock.reset_mock()
+    await attr.update(20)
+    assert attr.get() == 20
+    sync_setpoint_mock.assert_not_called()
+
+
 @pytest.mark.asyncio
 async def test_wait_for_predicate(mocker: MockerFixture):
     attr = AttrR(Int(), initial_value=0)