+
+ relation_added = asyncio.Event()
+ timeout = asyncio.Event()
+
+ class TestObserver(ModelObserver):
+ async def on_relation_add(self, delta, old, new, model):
+ if set(new.key.split()) == {'nrpe:general-info',
+ 'ubuntu:juju-info'}:
+ relation_added.set()
+ event_loop.call_later(2, timeout.set)
+
+ model.add_observer(TestObserver())
+
+ real_app_facade = ApplicationFacade.from_connection(model.connection())
+ mock_app_facade = mock.MagicMock()
+
+ async def mock_AddRelation(*args):
+ # force response delay from AddRelation to test race condition
+ # (see https://github.com/juju/python-libjuju/issues/191)
+ result = await real_app_facade.AddRelation(*args)
+ await relation_added.wait()
+ return result
+
+ mock_app_facade.AddRelation = mock_AddRelation
+
+ with mock.patch.object(ApplicationFacade, 'from_connection',
+ return_value=mock_app_facade):
+ my_relation = await run_with_interrupt(model.add_relation(
+ 'ubuntu',
+ 'nrpe',
+ ), timeout, event_loop)