def test_negate(self):
c1, c2 = Dummy(True), Dummy(False)
n = ConditionNode([c1, c2])
result = n.evaluate()
n.negate()
self.assertEqual(len(n), 1)
self.assertEqual(n.connector, AND)
self.assertEqual(n.children[0].children, [c1, c2])
self.assertEqual(n.children[0].connector, OR)
# We went from (c1 AND c2) to (!c1 or !c2)
self.assertEqual(n.evaluate(), not result)
self.assertIs(c1.v, False)
self.assertIs(c2.v, True)
n.negate()
self.assertIs(c1.v, True)
self.assertIs(c2.v, False)
self.assertEqual(len(n), 1)
self.assertEqual(n.connector, AND)
self.assertEqual(len(n.children[0]), 1)
# collapsing at this point should give us back the original node structure
n.collapse()
self.assertEqual(n.evaluate(), result)
self.assertEqual(n.children, [c1, c2])
self.assertEqual(n.connector, AND)
