validate hinted attributes on subcontrollers (#209)

Author: jsouter

src/fastcs/util.py

@@ -37,11 +37,20 @@ def validate_hinted_attributes(controller: BaseController):
     For each type-hinted attribute, validate that a corresponding instance exists in the
     controller with the correct access mode and datatype.
     """
-
-    hints = get_type_hints(type(controller))
-    alias_hints = {k: v for k, v in hints.items() if isinstance(v, _GenericAlias)}
-    for name, hint in alias_hints.items():
-        attr_class = get_origin(hint)
+    for subcontroller in controller.sub_controllers.values():
+        validate_hinted_attributes(subcontroller)
+    hints = {
+        k: v
+        for k, v in get_type_hints(type(controller)).items()
+        if isinstance(v, _GenericAlias | type)
+    }
+    for name, hint in hints.items():
+        if isinstance(hint, type):
+            attr_class = hint
+            attr_dtype = None
+        else:
+            attr_class = get_origin(hint)
+            attr_dtype = get_args(hint)[0]
         if not issubclass(attr_class, Attribute):
             continue
 
@@ -51,16 +60,13 @@ def validate_hinted_attributes(controller: BaseController):
                 f"Controller `{controller.__class__.__name__}` failed to introspect "
                 f"hinted attribute `{name}` during initialisation"
             )
-
-        if type(attr) is not attr_class:
+        if attr_class is not type(attr):
             raise RuntimeError(
-                f"Controller '{controller.__class__.__name__}' introspection of hinted "
-                f"attribute '{name}' does not match defined access mode. "
+                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__}'."
             )
-
-        attr_dtype = get_args(hint)[0]
-        if attr.datatype.dtype != attr_dtype:
+        if attr_dtype is not None and attr_dtype != attr.datatype.dtype:
             raise RuntimeError(
                 f"Controller '{controller.__class__.__name__}' introspection of hinted "
                 f"attribute '{name}' does not match defined datatype. "

tests/test_util.py

@@ -1,13 +1,15 @@
+import asyncio
 import enum
 
 import numpy as np
 import pytest
 from pvi.device import SignalR
 from pydantic import ValidationError
 
-from fastcs.attributes import AttrR, AttrRW
+from fastcs.attributes import Attribute, AttrR, AttrRW
 from fastcs.controller import Controller
 from fastcs.datatypes import Bool, Enum, Float, Int, String
+from fastcs.launch import FastCS
 from fastcs.util import (
     numpy_to_fastcs_datatype,
     snake_to_pascal,
@@ -136,3 +138,57 @@ class ControllerWrongEnumClass(Controller):
         "'hinted_enum' does not match defined datatype. "
         "Expected 'MyEnum', got 'MyEnum2'."
     )
+
+
+def test_hinted_attributes_verified_on_subcontrollers():
+    loop = asyncio.get_event_loop()
+
+    class ControllerWithWrongType(Controller):
+        hinted_missing: AttrR[int]
+
+        async def connect(self):
+            return
+
+    class TopController(Controller):
+        async def initialise(self):  # why does this not get called?
+            subcontroller = ControllerWithWrongType()
+            self.add_sub_controller("MySubController", subcontroller)
+
+    fastcs = FastCS(TopController(), [], loop)
+    with pytest.raises(RuntimeError, match="failed to introspect hinted attribute"):
+        fastcs.run()
+
+
+def test_hinted_attribute_access_mode_verified():
+    # test verification works with non-GenericAlias type hints
+    loop = asyncio.get_event_loop()
+
+    class ControllerAttrWrongAccessMode(Controller):
+        read_attr: AttrR
+
+        async def initialise(self):
+            self.read_attr = AttrRW(Int())
+
+    fastcs = FastCS(ControllerAttrWrongAccessMode(), [], loop)
+    with pytest.raises(RuntimeError, match="does not match defined access mode"):
+        fastcs.run()
+
+
+@pytest.mark.asyncio
+async def test_hinted_attributes_with_unspecified_access_mode():
+    class ControllerUnspecifiedAccessMode(Controller):
+        unspecified_access_mode: Attribute
+
+        async def initialise(self):
+            self.unspecified_access_mode = AttrRW(Int())
+
+    controller = ControllerUnspecifiedAccessMode()
+    await controller.initialise()
+    # no assertion thrown
+    with pytest.raises(
+        RuntimeError,
+        match=(
+            "does not match defined access mode. Expected 'Attribute', got 'AttrRW'"
+        ),
+    ):
+        validate_hinted_attributes(controller)