import unittest from unittest.mock import Mock from IPython.core import events import IPython.testing.tools as tt def ping_received(): pass class CallbackTests(unittest.TestCase): def setUp(self): self.em = events.EventManager(get_ipython(), {'ping_received': ping_received}) def test_register_unregister(self): cb = Mock() self.em.register('ping_received', cb) self.em.trigger('ping_received') self.assertEqual(cb.call_count, 1) self.em.unregister('ping_received', cb) self.em.trigger('ping_received') self.assertEqual(cb.call_count, 1) def test_cb_error(self): cb = Mock(side_effect=ValueError) self.em.register('ping_received', cb) with tt.AssertPrints("Error in callback"): self.em.trigger('ping_received') def test_unregister_during_callback(self): invoked = [False] * 3 def func1(*_): invoked[0] = True self.em.unregister('ping_received', func1) self.em.register('ping_received', func3) def func2(*_): invoked[1] = True self.em.unregister('ping_received', func2) def func3(*_): invoked[2] = True self.em.register('ping_received', func1) self.em.register('ping_received', func2) self.em.trigger('ping_received') self.assertEqual([True, True, False], invoked) self.assertEqual([func3], self.em.callbacks['ping_received'])