python retry with tenacity, disable `wait` for unittest

Question

I am using the tenacity library to use its @retry decorator.

I am using this to make a function which makes a HTTP-request \"repeat\" multiple times in

Answer 1

You can use unittest.mock module to mock some elements of tentacity library. In your case all decorators you use are classes e.g. retry is a decorator class defined here. So it might be little bit tricky, but I think trying to

mock.patch('tentacity.wait.wait_random_exponential.__call__', ...)

may help.

Answer 2

mock the base class wait func with:

mock.patch('tenacity.BaseRetrying.wait', side_effect=lambda *args, **kwargs: 0)

it always not wait

Answer 3

Thanks to discussion here, I found an elegant way to do this based on code from @steveb:

from tenacity import retry, stop_after_attempt, wait_exponential


@retry(reraise=True, stop=stop_after_attempt(5), wait=wait_exponential(multiplier=1, min=4, max=10))
def do_something_flaky(succeed):
    print('Doing something flaky')
    if not succeed:
        print('Failed!')
        raise Exception('Failed!')

And tests:

from unittest import TestCase, mock, skip
from main import do_something_flaky


class TestFlakyRetry(TestCase):
    def test_succeeds_instantly(self):
        try:
            do_something_flaky(True)
        except Exception:
            self.fail('Flaky function should not have failed.')

    def test_raises_exception_immediately_with_direct_mocking(self):
        do_something_flaky.retry.sleep = mock.Mock()
        with self.assertRaises(Exception):
            do_something_flaky(False)

    def test_raises_exception_immediately_with_indirect_mocking(self):
        with mock.patch('main.do_something_flaky.retry.sleep'):
            with self.assertRaises(Exception):
                do_something_flaky(False)

    @skip('Takes way too long to run!')
    def test_raises_exception_after_full_retry_period(self):
        with self.assertRaises(Exception):
            do_something_flaky(False)

Answer 4

The solution came from the maintainer of tenacity himself in this Github issue: https://github.com/jd/tenacity/issues/106

You can simply change the wait function temporarily for your unit test:

from tenacity import wait_none

func.retry.wait = wait_none()