@@ -16,6 +16,7 @@
 import collections
 import json
 import os
+import time
 
 import pytest
 
@@ -245,6 +246,37 @@ def test_delete(self, testref):
 ref.delete()
 assert ref.get() is None
 
+class TestListenOperations:
+"""Test cases for listening to changes to node values."""
+
+def test_listen(self, testref):
+self.events = []
+def callback(event):
+self.events.append(event)
+
+python = testref.parent
+registration = python.listen(callback)
+try:
+ref = python.child('users').push()
+assert ref.path == '/_adminsdk/python/users/' + ref.key
+assert ref.get() == ''
+
+self.wait_for(self.events, count=2)
+assert len(self.events) == 2
+
+assert self.events[1].event_type == 'put'
+assert self.events[1].path == '/users/' + ref.key
+assert self.events[1].data == ''
+finally:
+registration.close()
+
+@classmethod
+def wait_for(cls, events, count=1, timeout_seconds=5):
+must_end = time.time() + timeout_seconds
+while time.time() < must_end:
+if len(events) >= count:
+return
+raise pytest.fail('Timed out while waiting for events')
 
 class TestAdvancedQueries:
 """Test cases for advanced interactions via the db.Query interface."""