Now you have multiple tests you are probably feeling pretty good about your progress. However there are other ways to improve code efficiency further — you may notice that you've so far had to include a setUp() and a tearDown() method in each test file, going by the current constructs we've seen in this series. If you have several dozen tests then that’s a lot of code duplication! In this article we'll look at how to put the setUp()/tearDown() code common to all tests into a TestBase class, which can then be imported into each individual test file.
test_base.py
To start with, create a new file called test_base.py, in the same directory as your existing test cases.
Next, move your important statements that relate to the common setup (unittest, Marionette and time) into the file, along with a TestBase class containing the setUp() and tearDown() methods, and associated common helper functions (such as unlock_screen()). The file should look something like this:
import time
import unittest
from marionette import Marionette
class TestBase(unittest.TestCase):
def unlock_screen(self):
self.marionette.execute_script('window.wrappedJSObject.lockScreen.unlock();')
def kill_all(self):
self.marionette.switch_to_frame()
self.marionette.execute_async_script("""
// Kills all running apps, except the homescreen.
function killAll() {
let manager = window.wrappedJSObject.AppWindowManager;
let apps = manager.getApps();
for (let id in apps) {
let origin = apps[id].origin;
if (origin.indexOf('verticalhome') == -1) {
manager.kill(origin);
}
}
};
killAll();
// return true so execute_async_script knows the script is complete
marionetteScriptFinished(true);
""")
def setUp(self):
# Create the client for this session. Assuming you're using the default port on a Marionette instance running locally
self.marionette = Marionette()
self.marionette.start_session()
# Unlock the screen
self.unlock_screen()
# kill all open apps
self.kill_all()
# Switch context to the homescreen iframe and tap on the contacts icon
time.sleep(2)
home_frame = self.marionette.find_element('css selector', 'div.homescreen iframe')
self.marionette.switch_to_frame(home_frame)
def tearDown(self):
# Close the Marionette session now that the test is finished
self.marionette.delete_session()
Updating your test files
With your test_base.py file created, you need to import TestBase into your test files, and the test classes need to be changed to extend the TestBase class:
import unittest
from marionette import Wait
from marionette import By
from test_base import TestBase
class TestContacts(TestBase):
def test(self):
# Tests in here
if __name__ == '__main__':
unittest.main()
Try running your test file again.
It may not look like much now but when you have dozens or hundreds of tests this really saves a lot of duplicate code.