reliably kill phantomjs launched in setUpClass if derived class' setUpClass fails - unit-testing

Question

I wrote a SeleniumTestCase class that launches PhantomJS in its setUpClass and kills it in its tearDownClass. However, if a derived class' setUpClass raises an error, the PhantomJS process is left hanging because SeleniumTestCase.tearDownClass doesn't get called.
from django.test import LiveServerTestCase
import sys, signal, os
from selenium import webdriver
errorShots = os.path.join(os.path.dirname(os.path.abspath(__file__)), '..', "errorShots")
class SeleniumTestCase(LiveServerTestCase):
#classmethod
def setUpClass(cls):
"""
Launches PhantomJS
"""
super(SeleniumTestCase, cls).setUpClass()
cls.browser = webdriver.PhantomJS()
#classmethod
def tearDownClass(cls):
"""
Saves a screenshot if the test failed, and kills PhantomJS
"""
print 'Tearing down...'
if cls.browser:
if sys.exc_info()[0]:
try:
os.mkdir(errorShots)
except:
pass
errorShotPath = os.path.join(
errorShots,
"ERROR_phantomjs_%s_%s.png" % (cls._testMethodName, datetime.datetime.now().isoformat())
)
cls.browser.save_screenshot(errorShotPath)
print 'Saved screenshot to', errorShotPath
cls.browser.service.process.send_signal(signal.SIGTERM)
cls.browser.quit()
class SetUpClassTest(SeleniumTestCase):
#classmethod
def setUpClass(cls):
print 'Setting Up'
super(SetUpClassTest, cls).setUpClass()
raise Error('gotcha!')
def test1(self):
pass
Output (note that "Tearing Down" doesn't get printed)
$ ./manage.py test
Creating test database for alias 'default'...
Setting Up
E
======================================================================
ERROR: setUpClass (trucks.tests.SetUpClassTest)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/Users/andy/leased-on/trucks/tests.py", line 1416, in setUpClass
raise Error('gotcha!')
NameError: global name 'Error' is not defined
----------------------------------------------------------------------
Ran 0 tests in 1.034s
FAILED (errors=1)
Destroying test database for alias 'default'...
How can I kill PhantomJS after a suite's setUpClass fails?
I know I could switch to using setUp and addCleanup, but I want to avoid relaunching PhantomJS (and logging back into my app with it) before every single test.

Answer 1

I decided to use setUpModule and tearDownModule to launch and kill PhantomJS. I put the screenshot-saving code in an addCleanup hook.
from django.test import LiveServerTestCase
from selenium import webdriver
import sys
import signal
import os
import unittest
errorShots = os.path.join(os.path.dirname(os.path.abspath(__file__)), '..', "errorShots")
browser = None
def setUpModule():
"""
Launches PhantomJS
"""
global browser
sys.stdout.write('Starting PhantomJS...')
sys.stdout.flush()
browser = webdriver.PhantomJS()
print 'done'
def tearDownModule():
"""
kills PhantomJS
"""
if browser:
sys.stdout.write('Killing PhantomJS...')
sys.stdout.flush()
browser.service.process.send_signal(signal.SIGTERM)
browser.quit()
print 'done'
class SeleniumTestCase(LiveServerTestCase):
def setUp(self):
self.addCleanup(self.cleanup)
def cleanup(self):
"""
Saves a screenshot if the test failed
"""
if sys.exc_info()[0]:
try:
os.mkdir(errorShots)
except:
pass
errorShotPath = os.path.join(
errorShots,
"ERROR_phantomjs_%s_%s.png" % (self._testMethodName, datetime.datetime.now().isoformat())
)
browser.save_screenshot(errorShotPath)
print '\nSaved screenshot to', errorShotPath