How to skip the rest of tests in the class if one has failed?

Alex Okrushko picture Alex Okrushko · Sep 13, 2012 · Viewed 22.3k times · Source

I'm creating the test cases for web-tests using Jenkins, Python, Selenium2(webdriver) and Py.test frameworks.

So far I'm organizing my tests in the following structure:

each Class is the Test Case and each test_ method is a Test Step.

This setup works GREAT when everything is working fine, however when one step crashes the rest of the "Test Steps" go crazy. I'm able to contain the failure inside the Class (Test Case) with the help of teardown_class(), however I'm looking into how to improve this.

What I need is somehow skip(or xfail) the rest of the test_ methods within one class if one of them has failed, so that the rest of the test cases are not run and marked as FAILED (since that would be false positive)

Thanks!

UPDATE: I'm not looking or the answer "it's bad practice" since calling it that way is very arguable. (each Test Class is independent - and that should be enough).

UPDATE 2: Putting "if" condition in each test method is not an option - is a LOT of repeated work. What I'm looking for is (maybe) somebody knows how to use the hooks to the class methods.

Answer

hpk42 picture hpk42 · Sep 25, 2012

I like the general "test-step" idea. I'd term it as "incremental" testing and it makes most sense in functional testing scenarios IMHO.

Here is a an implementation that doesn't depend on internal details of pytest (except for the official hook extensions). Copy this into your conftest.py:

import pytest

def pytest_runtest_makereport(item, call):
    if "incremental" in item.keywords:
        if call.excinfo is not None:
            parent = item.parent
            parent._previousfailed = item

def pytest_runtest_setup(item):
    previousfailed = getattr(item.parent, "_previousfailed", None)
    if previousfailed is not None:
        pytest.xfail("previous test failed (%s)" % previousfailed.name)

If you now have a "test_step.py" like this:

import pytest

@pytest.mark.incremental
class TestUserHandling:
    def test_login(self):
        pass
    def test_modification(self):
        assert 0
    def test_deletion(self):
        pass

then running it looks like this (using -rx to report on xfail reasons):

(1)hpk@t2:~/p/pytest/doc/en/example/teststep$ py.test -rx
============================= test session starts ==============================
platform linux2 -- Python 2.7.3 -- pytest-2.3.0.dev17
plugins: xdist, bugzilla, cache, oejskit, cli, pep8, cov, timeout
collected 3 items

test_step.py .Fx

=================================== FAILURES ===================================
______________________ TestUserHandling.test_modification ______________________

self = <test_step.TestUserHandling instance at 0x1e0d9e0>

    def test_modification(self):
>       assert 0
E       assert 0

test_step.py:8: AssertionError
=========================== short test summary info ============================
XFAIL test_step.py::TestUserHandling::()::test_deletion
  reason: previous test failed (test_modification)
================ 1 failed, 1 passed, 1 xfailed in 0.02 seconds =================

I am using "xfail" here because skips are rather for wrong environments or missing dependencies, wrong interpreter versions.

Edit: Note that neither your example nor my example would directly work with distributed testing. For this, the pytest-xdist plugin needs to grow a way to define groups/classes to be sent whole-sale to one testing slave instead of the current mode which usually sends test functions of a class to different slaves.