Plugin for nose or py.test that automatically reruns flaky tests.
Upcoming Breaking Change!
When Flaky was released through version 0.3.0, it was released under the namespace box.test. In version 0.4.0, importing flaky became easier:
from flaky import flaky
from box.test.flaky import flaky
In version 1.0.0, however, you will no longer be able to import flaky from box.test.
Flaky is a plugin for nose or py.test that automatically reruns flaky tests.
Ideally, tests reliably pass or fail, but sometimes test fixtures must rely on components that aren’t 100% reliable. With flaky, instead of removing those tests or marking them to @skip, they can be automatically retried.
Like any nose plugin, flaky can be activated via the command line:
To mark a test as flaky, simply decorate it with @flaky:
@flaky def test_something_that_usually_passes(self): value_to_double = 21 result = get_result_from_flaky_doubler(value_to_double) self.assertEqual(result, value_to_double * 2, 'Result doubled incorrectly.')
By default, flaky will retry a failing test once, but that behavior can be overridden by passing values to the flaky decorator. It accepts two parameters: max_runs, and min_passes; flaky will run tests up to max_runs times, until it has succeeded min_passes times. Once a test passes min_passes times, it’s considered a success; once it has been run max_runs times without passing min_passes times, it’s considered a failure.
@flaky(max_runs=3, min_passes=2) def test_something_that_usually_passes(self): """This test must pass twice, and it can be run up to three times.""" value_to_double = 21 result = get_result_from_flaky_doubler(value_to_double) self.assertEqual(result, value_to_double * 2, 'Result doubled incorrectly.')
In addition to marking a single test flaky, entire test cases can be marked flaky:
@flaky class TestMultipliers(TestCase): def test_flaky_doubler(self): value_to_double = 21 result = get_result_from_flaky_doubler(value_to_double) self.assertEqual(result, value_to_double * 2, 'Result doubled incorrectly.') @flaky(max_runs=3) def test_flaky_tripler(self): value_to_triple = 14 result = get_result_from_flaky_tripler(value_to_triple) self.assertEqual(result, value_to_triple * 3, 'Result tripled incorrectly.')
The @flaky class decorator will mark test_flaky_doubler as flaky, but it won’t override the 3 max_runs for test_flaky_tripler (from the decorator on that test method).
Additional usage examples are in the code - see test/test_example.py
To install, simply:
pip install flaky
Create a virtual environment and install packages -
mkvirtualenv flaky pip install -r requirements-dev.txt
Run all tests using -
The tox tests include code style checks via pep8 and pylint.
Copyright and License
Copyright 2014 Box, Inc. All rights reserved. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.