Examples

Some examples are available under tests/e2e of this repo: https://github.com/trinhngocthuyen/e2e-mobile/tree/main/tests/e2e

Take a look at test_settings.py, for example. There are several tests to verify features under this Settings screen.

Running a particular test inside a test file

To run a particular test with pytest:

$ pytest <path/to/file>::<test_method>

For instance, to run the test test_forgot_password inside this file:

$ pytest tests/e2e/test_settings.py::test_forgot_password

Leveraging fixtures for reusable test setup

As you can see, in this file, we create some fixtures such as take_me_to_settings and take_me_to_login.

@pytest.fixture
def take_me_to_settings(tester: Tester):
    tester.ui.home.skip_tutorial()
    tester.ui.home.go_to_settings()


@pytest.fixture
def take_me_to_login(tester: Tester, take_me_to_settings):
    tester.ui.settings.button('Log in').tap()
    tester.ui.element('Log in to your account').must_exist()
    tester.ui.element('Username').must_exist()
    tester.ui.element('Password').must_exist()

These fixtures are incredibly useful. They can be used as a shortcut to performing necessary actions to enter a specific screen. All you need to do is to add the fixture to the test method signature. Then, the code inside those fixtures will be automatically executed. How convenient! Right 😄?

def test_login_error(tester: Tester, take_me_to_login): # <-- add the fixture here
    ...

Using xpath when accessibility labels/ids are missing

When inspecting the elements, you should see xml of the username textfield like this:

<XCUIElementTypeTextField type="XCUIElementTypeTextField" value="enter username" label="" enabled="true" visible="true" accessible="true" x="51" y="233" width="288" height="29" index="4">

As you notice, the label="" demonstrates that the accessibility label is missing. However, we can use xpath queries to overcome this issue.

At first sight, we can query the element of type XCUIElementTypeTextField having value as “enter username”:

tester.ui.textfield(xpath='//XCUIElementTypeTextField[@value="enter username"]').input('foo')

This xpath works like a charm. Yet, it’s still iOS-specific because of the type XCUIElementTypeTextField. To make it more universal for both platforms, we can update the query to accept any type.

tester.ui.textfield(xpath='//*[@value="enter username"]').input('foo')

–

Many argue that using xpath is slow. And using xpath queries accepting any type like above is even slower. However, in the context of end-to-end testing, does it matter that much if the queries run 0.5s slower, or even 1-2s slower. Sometimes, it’s a compromise between performance and maintenance cost. I’d leave that up to you to decide what’s best for your case 😉.