reword some comments and error messages

Author: James Souter

src/fastcs/controller.py

@@ -45,7 +45,8 @@ async def initialise(self):
         pass
 
     async def attribute_initialise(self) -> None:
-        # Initialise any registered handlers for attributes
+        """Register update and send callbacks for attributes on this controller
+        and all subcontrollers"""
         self._add_io_callbacks()
 
         for controller in self.get_sub_controllers().values():
@@ -56,7 +57,6 @@ def _add_io_callbacks(self):
             ref = attr.io_ref if attr.has_io_ref() else None
             io = self._attribute_ref_io_map.get(type(ref))
             if isinstance(attr, AttrW):
-                # is it on process or write_display?
                 attr.add_process_callback(self._create_send_callback(io, attr, ref))
             if isinstance(attr, AttrR):
                 attr.add_update_callback(self._create_update_callback(io, attr, ref))
@@ -72,15 +72,14 @@ async def send_callback(value):
 
             async def send_callback(value):
                 await io.send(attr, value)
-                # TODO, should we just then call the above send_callback here?
 
         return send_callback
 
     def _create_update_callback(self, io, attr, ref):
         if ref is None:
 
             async def error_callback():
-                raise RuntimeError("Attributes without io_ref can not be updated")
+                raise RuntimeError("Can't call update on Attributes without an io_ref")
 
             return error_callback
         else:

tests/test_attribute.py

@@ -88,8 +88,7 @@ class ControllerNoIO(Controller):
 
     with pytest.raises(AssertionError, match="does not have an AttributeIO"):
         ControllerNoIO()
-    # TODO, is it okay that we need to initialise the controller
-    # before the callbacks get assigned?
+
     await c.initialise()
     await c.attribute_initialise()
     await c.my_attr.update()
@@ -245,8 +244,8 @@ async def update(self, attr):
     # default callbacks are not provided by AttributeIO subclasses
 
     with pytest.raises(
-        RuntimeError, match="Attributes without io_ref can not be updated"
-    ):  # TODO, we need a clearer error message for this
+        RuntimeError, match="Can't call update on Attributes without an io_ref"
+    ):
         await c.no_ref.update()
 
     process_spy = mocker.spy(c.no_ref, "update_display_without_process")