Automatic screenshots when test fail by Selenium Webdriver in Python

Question

I want to automatic capturing screenshots if my webdriver tests failed (any exception or assertion error). I am using Python unittest and Selenium Webdriver. Does anyone hav

Answer 1

Here is a solution using a decorator that wrapps every method on a class that starts test_ with a wrapper that takes a screenshot if the method raises and Exception. The browser_attr is used to tell the decorator how to obtain the web browser (driver).

from functools import partialmethod


def sreenshotOnFail(browser_attr='browser'):
    def decorator(cls):
        def with_screen_shot(self, fn, *args, **kwargs):
            """Take a Screen-shot of the drive page, when a function fails."""
            try:
                return fn(self, *args, **kwargs)
            except Exception:
                # This will only be reached if the test fails
                browser = getattr(self, browser_attr)
                filename = 'screenshot-%s.png' % fn.__name__
                browser.get_screenshot_as_file(filename)
                print('Screenshot saved as %s' % filename)
                raise

        for attr, fn in cls.__dict__.items():
            if attr[:5] == 'test_' and callable(fn):
                setattr(cls, attr, partialmethod(with_screen_shot, fn))

        return cls
    return decorator


@sreenshotOnFail()
class TestDemo(unittest.TestCase):
    def setUp(self):
        """Set up the Firefox Browser and the Tear Down."""
        self.browser = webdriver.Firefox()

    def test_demo2(self):
        """A test case that fails because assert."""
        self.driver.get("https://stackoverflow.com")
        self.assertEqual(True, False)