def test_traverse_changed(self):
calls = []
op = (lambda dt: calls.append(dt) or str)
field = Field('spam', ANY)
transformed = field.traverse(op)
self.assertIsNot(transformed, field)
self.assertEqual(transformed, Field('spam', str))
self.assertEqual(calls, [
ANY,
])
def test_traverse_noop(self):
calls = []
op = (lambda dt: calls.append(dt) or dt)
field = Field('spam', Union(str, int))
transformed = field.traverse(op)
self.assertIs(transformed, field)
self.assertCountEqual(
calls,
[
# Note that it did not recurse into Union(str, int).
Union(str, int),
])