pytest-loop is a plugin for pytest that makes it easy to loop a single test, or multiple tests, a specific number of times or for a certain duration of time. This plugin merges pytest-repeat and pytest-stress with a fix for test results.
You will need the following prerequisites in order to use pytest-loop: - Python 3.7+ or PyPy - pytest 7 or newer
To install pytest-loop:
$ pip install pytest-loopUse the --loop command line option to specify how many times you want
your test, or tests, to be run:
$ pytest --loop=10 test_file.pyEach test collected by pytest will be run n times.
If you want to mark a test in your code to be looped a number of times, you
can use the @pytest.mark.loop(n) decorator:
import pytest
@pytest.mark.loop(3)
def test_loop_decorator():
passLoop tests for 30 seconds:
$ pytest --seconds 30
Loop tests for 45 minutes:
$ pytest --minutes 45
Loop tests for 8 hours:
$ pytest --hours 8
Loop tests for 1 hour 8 minutes and 9 seconds:
$ pytest --hours 1 --minutes 8 --seconds 9
Need to wait some time after each test loop?:
$ pytest --delay 5 --hours 4 --minutes 30
You can also add these values to config files:
[pytest] addopts = --hours 1 --minutes 30
Note: These loop times include setup and teardown operations as well. So if you have a test setup that takes 5 seconds, your actual tests will run for 5 seconds less than your desired time.
If you are trying to diagnose an intermittent failure, it can be useful to run the same
test over and over again until it fails. You can use pytest's -x option in
conjunction with pytest-loop to force the test runner to stop at the first failure.
For example:
$ pytest --loop=1000 -x test_file.pyThis will attempt to run test_file.py 1000 times, but will stop as soon as a failure occurs.
$ pytest --hours 10 -x test_file.This will attempt to run test_file.py for 10 hours, but will stop as soon as a failure occurs.
Unfortunately pytest-loop is not able to work with unittest.TestCase test classes.
These tests will simply always run once, regardless of --loop, and show a warning.