pytest-rerunfailures

pytest-rerunfailures is a plugin for py.test that re-runs tests to eliminate intermittent failures.

Requirements

You will need the following prerequisites in order to use pytest-rerunfailures:

Python 2.6, 2.7, 3.3, 3.4, 3.5, PyPy, or PyPy3
py.test 2.4.2 or newer, except Python 3.5 that needs py.test 2.7.3 or newer

Installation

To install pytest-rerunfailures:

$ pip install pytest-rerunfailures

Re-run all failures

To re-run all test failures, use the --reruns command line option with the maximum number of times you'd like the tests to run:

$ py.test --rerun 5

Re-run individual failures

To mark individual tests as flaky, and have them automatically re-run when they fail, add the flaky mark with the maximum number of times you'd like the test to run:

@pytest.mark.flaky(reruns=5)
def test_example():
    import random
    assert random.choice([True, False])

Note that when teardown fails, two reports are generated for the case, one for the test case and the other for the teardown error.

Output

Here's an example of the output provided by the plugin when run with --reruns 2 and -r aR:

test_report.py RRF

================================== FAILURES ==================================
__________________________________ test_fail _________________________________

    def test_fail():
>       assert False
E       assert False

test_report.py:9: AssertionError
============================ rerun test summary info =========================
RERUN test_report.py::test_fail
RERUN test_report.py::test_fail
============================ short test summary info =========================
FAIL test_report.py::test_fail
======================= 1 failed, 2 rerun in 0.02 seconds ====================

Note that output will show all re-runs. Tests that fail on all the re-runs will be marked as failed. Due to a current limitation in pytest-xdist, when running tests in parallel only the final result will be included in the output.

Compatibility

This plugin may not be used with class, module, and package level fixtures.
This plugin is not compatible with pytest-xdist's --looponfail flag.
This plugin is not compatible with the core --pdb flag.
The support for Python 3.5 is limited to pytest 2.7.3 and higher. (Will break with TypeError: Call constructor takes either 0 or 3 positional arguments for older versions, see pytest-dev/pytest#744)

pkch/pytest-rerunfailures