def test_traverse_changed(self):
calls = []
op = (lambda dt: calls.append(dt) or Field(dt.name, str))
fields = Fields(
Field('spam', ANY),
Field('eggs', None),
)
transformed = fields.traverse(op)
self.assertIsNot(transformed, fields)
self.assertEqual(transformed,
Fields(
Field('spam', str),
Field('eggs', str),
))
self.assertEqual(calls, [
Field('spam', ANY),
Field('eggs', None),
])
def test_traverse_noop(self):
calls = []
op = (lambda dt: calls.append(dt) or dt)
fields = Fields(
Field('spam'),
Field('ham'),
Field('eggs'),
)
transformed = fields.traverse(op)
self.assertIs(transformed, fields)
self.assertCountEqual(
calls,
[
# Note that it did not recurse into the fields.
Field('spam'),
Field('ham'),
Field('eggs'),
])