Adds test for #110.

Author: tcr3dr

tests/sitl/test_110.py

@@ -0,0 +1,49 @@
+from droneapi.lib import VehicleMode
+from pymavlink import mavutil
+import time
+import sys
+import os
+
+def test_110(local_connect):
+    api = local_connect()
+    v = api.get_vehicles()[0]
+    
+    # Change the vehicle into STABILIZE mode
+    v.mode = VehicleMode("STABILIZE")
+
+    # NOTE wait crudely for ACK on mode update
+    time.sleep(3)
+
+    # Define example callback for mode
+    allow_callback = True
+    bad_call = [False]
+    def armed_callback(attribute):
+        if not allow_callback:
+            bad_call[0] = True
+
+    # Only one of the same observer fn should be added.
+    v.add_attribute_observer('armed', armed_callback)
+    v.add_attribute_observer('armed', armed_callback)
+    v.add_attribute_observer('armed', armed_callback)
+    v.add_attribute_observer('armed', armed_callback)
+    allow_callback = True
+
+    # Disarm and see update.
+    v.armed = False
+    v.flush()
+
+    time.sleep(3)
+
+    # Rmove (all) observers.
+    v.remove_attribute_observer('armed', armed_callback)
+    v.remove_attribute_observer('armed', armed_callback)
+    allow_callback = False
+
+    # Re-arm and see update.
+    v.armed = True
+    v.flush()
+
+    time.sleep(3)
+
+    # Make sure no bad calls happened.
+    assert not bad_call[0], "Callback should not have been called once removed."