Selenium testing framework for Django applications
sbo-selenium is a framework primarily intended to help write Selenium tests for Django applications, although it may be useful in testing other kinds of web applications as well.
Add ‘sbo-selenium’ to the requirements for the application being tested, and add ‘sbo_selenium’ to the INSTALLED_APPS setting. Install the new dependency as usual for the containing project; for SBO packages this is typically:
pip install -r requirements/tests.txt
To run tests using a particular browser, it needs to already be installed. To drive Chrome via Selenium, you’ll need to install both Chrome itself and then chromedriver:
- Download the correct ChromeDriver from http://chromedriver.storage.googleapis.com/index.html
- Put the binary, chromedriver, somewhere on your path (ex: /usr/local/bin/chromedriver)
On Mac OS X, if you have Homebrew installed you can instead run brew install chromedriver.
To test Mobile Safari in the iPhone simulator, you’ll first need to do the following:
- Install Xcode
- From the Downloads tab of the Xcode Preferences dialog, install “Command Line Tools” and one of the iOS Simulator components (probably the latest one)
- Download and run Appium
- Check the “Use Mobile Safari” checkbox
- If you want to test in the iPad form factor, check the “Force Device” checkbox and make sure “iPad” is selected next to it
- Click the “Launch” button
To test Opera or Safari, you’ll need to download the Selenium standalone server jar file and configure the path to it in the SELENIUM_JAR_PATH setting described below.
Note that all of these browsers and more can be tested using Sauce OnDemand; see below for details.
sbo-selenium uses a few Django settings to configure some aspects of test runs:
- DJANGO_LIVE_TEST_SERVER_ADDRESS - The address at which to run the test server (this will be used as the environment variable of the same name described in the Django testing documentation). Default value is 'localhost:9090'.
- SELENIUM_DEFAULT_BROWSER - The web browser to use for tests when none is specified. Default value is 'chrome'.
- SELENIUM_DEFAULT_TESTS - The Selenium test(s) to be run by default when none are specified. Should be an array of nose-compatible test specifications (see Running Tests below for examples). Default value is an empty list.
- SELENIUM_PAGE_LOAD_TIMEOUT - The number of seconds to wait for a response to a GET request before considering it to have failed. Default value is 10 seconds. (This is particularly important when using Sauce Connect, as it sometimes fails to connect properly, such that every single page load stalls indefinitely.)
- SELENIUM_JAR_PATH - Absolute path of the Selenium standalone server jar file.
- SELENIUM_POLL_FREQUENCY - The number of seconds to wait after a failed operation before trying again. Default value is 0.5 seconds.
- SELENIUM_SAUCE_API_KEY - The API key for the Sauce Labs account to use for running tests.
- SELENIUM_SAUCE_CONNECT_PATH - Absolute path of the Sauce Connect binary, used when testing a site that isn’t visible to the internet at large via Sauce Labs. If not set but other parameters indicate Sauce usage, it’s assumed that the site being tested is publicly accessible.
- SELENIUM_SAUCE_USERNAME - The username for the Sauce Labs account to use for running tests.
- SELENIUM_SAUCE_VERSION - The version of Selenium to ask Sauce Labs to use in the provided virtual machine. If omitted, the current default version provided by Sauce Labs is used. Documentation on the available versions and current default can be found here.
- SELENIUM_SCREENSHOT_DIR - Absolute path of the directory in which to save screenshots taken over the course of running tests (these can be useful for debugging test failures). The directory will be created if it doesn’t already exist. If the tests are being run via Sauce Labs, screenshots are not created in this directory because that service generates screenshots for us.
- SELENIUM_TIMEOUT - The number of seconds to wait after an operation first failed until giving up and declaring it an error. Default value is 10 seconds.
Note that some test runners (such as nose) may not always show errors logged during test setup and teardown. To consistently get this output, you may want to configure a logging handler that outputs to file (in addition to any that may be outputting to console).
We’re creating Selenium tests as Python classes. Typically you’ll want to create a common subclass of sbo_selenium.SeleniumTestCase which each of your application’s actual test classes will in turn inherit from. This main class will contain methods for common operations like logging in and logging out, verifying that common page content is present, loading typical test data, and so forth. This can be defined in the application’s tests.selenium.__init__ module. Avoid method names with “test” in them, as the test runner is likely to mistake them for actual standalone tests.
Each related set of tests should then be created as methods in a subclass of this common test case class which lives in its own file within tests.selenium (or a subdirectory thereof). These test methods should start with test_ so the test runner can find them, and it’s generally good practice to have utility methods which aren’t tests themselves start with an underscore. Typically each test class will cover functionality on a single page or a set of closely related pages.
Tests can be run via the “selenium” management command:
./manage.py selenium --settings=myapp.selenium_settings
Or to specify which test(s) to run rather than using the defaults specified in the settings file:
./manage.py selenium myapp.tests.selenium.test_module:TestClass.test_method myotherapp/tests/selenium --settings=myapp.selenium_settings
Having a separate settings file for the Selenium tests isn’t a requirement, but in practice you’ll probably want to use different settings for the tests than you do for development (for example, to make sure that DEBUG=False). If you don’t want to type out the settings parameter each time, a simple shell script should do the trick:
#!/bin/sh ./manage.py selenium $@ --settings=myapp.selenium_settings
All the usual methods that nose uses to identify tests should work:
directory/of/tests python.module python.module:TestClass python.module:TestClass.test_method
(Note that a specifying a package, like myapp.tests.selenium when the actual tests are defined in modules within that package, does NOT work.)
By default, tests are run in the browser specified by SELENIUM_DEFAULT_BROWSER. You can use the -b or --browser parameter to change this:
./manage.py selenium -b firefox ./manage.py selenium --browser=safari
Valid browser names are “chrome”, “firefox”, “htmlunit”, “ios”, “opera”, “phantomjs”, and “safari” (“ipad”, “iphone”, and “ipod” are treated as synonyms for “ios”, the form factor is chosen in Appium). Alternatively, tests can be run at Sauce Labs; see below for details.
You can also specify the number of times to run the tests (for example, if you have a test that is failing intermittently for some reason and want to run it a few times to increase the odds of encountering the error):
./manage.py selenium -n 5
Instead of running tests in a local browser, they can be run on one in a virtual machine hosted at Sauce Labs. Support for this in sbo-selenium is designed to play nicely with the Jenkins Sauce OnDemand plugin. For running tests in Jenkins, just install that plugin and configure it for the job you want to run. On a local machine, you’ll need to set the SELENIUM_SAUCE_* Django settings described above and use a couple of command-line parameters in addition to the -b browser name setting mentioned previously:
- -p or --platform - The name and version of the operating system to use.
- --browser-version - The version number of the browser to use.
The valid values for these can be found on the Sauce Labs website.
There’s also a --tunnel-identifier parameter which can be used to utilize a named Sauce Connect tunnel; this is particularly useful if you intend to run multiple Connect instances against the same account simultaneously (like on multiple Jenkins slave nodes). For more about what these tunnels are and when to use them, see the Sauce Labs documentation on the topic.