allow datatype hinting on Attributes with undefined access mode

Author: James Souter

src/fastcs/util.py

@@ -62,13 +62,12 @@ def validate_hinted_attributes(controller: BaseController):
             )
         if attr_class is not type(attr):
             # skip validation if access mode not specified
-            if attr_class is Attribute and isinstance(attr, Attribute):
-                continue
-            raise RuntimeError(
-                f"Controller '{controller.__class__.__name__}' introspection of hinted "
-                f"attribute '{name}' does not match defined access mode. "
-                f"Expected '{attr_class.__name__}', got '{type(attr).__name__}'."
-            )
+            if not (attr_class is Attribute and isinstance(attr, Attribute)):
+                raise RuntimeError(
+                    f"Controller '{controller.__class__.__name__}' introspection of "
+                    f"hinted attribute '{name}' does not match defined access mode. "
+                    f"Expected '{attr_class.__name__}', got '{type(attr).__name__}'."
+                )
         if attr_dtype is not None and attr_dtype != attr.datatype.dtype:
             raise RuntimeError(
                 f"Controller '{controller.__class__.__name__}' introspection of hinted "

tests/test_util.py

@@ -186,3 +186,14 @@ async def initialise(self):
     await controller.initialise()
     # no assertion thrown
     validate_hinted_attributes(controller)
+
+    class ControllerUnspecifiedAccessModeWrongType(Controller):
+        unspecified_access_mode_wrong_type: Attribute[int]
+
+        async def initialise(self):
+            self.unspecified_access_mode_wrong_type = AttrRW(Float())
+
+    controller = ControllerUnspecifiedAccessModeWrongType()
+    await controller.initialise()
+    with pytest.raises(RuntimeError, match="does not match defined datatype"):
+        validate_hinted_attributes(controller)