Improve coverage in register_sub_controller

src/fastcs/controller.py

@@ -27,11 +27,11 @@ def _bind_attrs(self) -> None:
     def register_sub_controller(self, name: str, sub_controller: SubController):
         if name in self.__sub_controller_tree.keys():
             raise ValueError(
-                f"Controller {self} already has a sub controller registered as {name}"
+                f"Controller {self} already has a SubController registered as {name}"
             )
         if sub_controller.path:
             raise ValueError(
-                f"Sub controller is already registered under {sub_controller.path}"
+                f"SubController is already registered under {sub_controller.path}"
             )
 
         self.__sub_controller_tree[name] = sub_controller

tests/test_controller.py

@@ -1,3 +1,5 @@
+import pytest
+
 from fastcs.controller import Controller, SubController
 from fastcs.mapping import _get_single_mapping, _walk_mappings
 
@@ -17,3 +19,13 @@ def test_controller_nesting():
         _get_single_mapping(sub_controller),
         _get_single_mapping(sub_sub_controller),
     ]
+
+    with pytest.raises(
+        ValueError, match=r"Controller .* already has a SubController registered as .*"
+    ):
+        controller.register_sub_controller("a", SubController())
+
+    with pytest.raises(
+        ValueError, match=r"SubController is already registered under .*"
+    ):
+        controller.register_sub_controller("c", sub_controller)