pytest-rerunfailures is a plugin for py.test that re-runs tests to eliminate intermittent failures.
You will need the following prerequisites in order to use pytest-rerunfailures:
- Python 2.7, 3.4, 3.5, 3.6, 3.7, PyPy, or PyPy3
- pytest 2.8.7 or newer
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:
$ pytest --reruns 5
Failed fixture or setup_class will also be re-executed.
To add a delay time between re-runs use the
--reruns-delay command line
option with the amount of seconds that you would like wait before the next
test re-run is launched:
$ pytest --reruns 5 --reruns-delay 1
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.
You can also specify the re-run delay time in the marker:
@pytest.mark.flaky(reruns=5, reruns_delay=2) def test_example(): import random assert random.choice([True, False])
Here's an example of the output provided by the plugin when run with
--reruns 2 and
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.
- 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.
- Test execution count can be retrieved from the
execution_countattribute in test
item's object. Example:
@hookimpl(tryfirst=True, hookwrapper=True) def pytest_runtest_makereport(item, call): print(item.execution_count)