Add guard to global updater (#174)

* Add guard to global updater

* clean up

tests/test_gateway.py

@@ -730,6 +730,40 @@ async def test_pollers_skip(
     assert "Device availability checker interval skipped" in caplog.text
 
 
+async def test_global_updater_guards(
+    zha_gateway: Gateway,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Test global updater guards."""
+
+    already_registered = (
+        "listener already registered with global updater - nothing to register"
+    )
+    not_registered = "listener not registered with global updater - nothing to remove"
+
+    assert already_registered not in caplog.text
+    assert not_registered not in caplog.text
+
+    def listener():
+        pass
+
+    zha_gateway.global_updater.register_update_listener(listener)
+
+    assert already_registered not in caplog.text
+
+    zha_gateway.global_updater.register_update_listener(listener)
+
+    assert already_registered in caplog.text
+
+    zha_gateway.global_updater.remove_update_listener(listener)
+
+    assert not_registered not in caplog.text
+
+    zha_gateway.global_updater.remove_update_listener(listener)
+
+    assert not_registered in caplog.text
+
+
 async def test_gateway_handle_message(
     zha_gateway: Gateway,
     zha_dev_basic: Device,  # pylint: disable=redefined-outer-name

zha/application/helpers.py

@@ -397,11 +397,21 @@ def stop(self):
     def register_update_listener(self, listener: Callable):
         """Register an update listener."""
         if listener in self._update_listeners:
+            _LOGGER.debug(
+                "listener already registered with global updater - nothing to register: %s",
+                listener,
+            )
             return
         self._update_listeners.append(listener)
 
     def remove_update_listener(self, listener: Callable):
         """Remove an update listener."""
+        if listener not in self._update_listeners:
+            _LOGGER.debug(
+                "listener not registered with global updater - nothing to remove: %s",
+                listener,
+            )
+            return
         self._update_listeners.remove(listener)
 
     @periodic(_REFRESH_INTERVAL)