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Using Interfaces

Interfaces are Python classes that allow easy access to hardware and software modules commonly used in testing, such as UART, BLE, or J-Link devices. Interfaces are similar to drivers because they present a documented interface to some module.

Interfaces are not PyTest fixtures, but they can be used to easily create them. A typical use-case would be a simple fixture that yields an instance of an interface::

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@pytest.fixture
def some_fixture():

    interface = SomeInterface()

    yield interface

    interface.cleanup()

This fixture creates an instance of the interface, yields it to the test, and then cleans up after the test is done. For more details on how PyTest fixtures work, see their official documentation.

The test would then use the fixture in order to access the interface::

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def test_something(some_fixture):

    data = some_fixture.some_interface_method()

    assert data == "Hello World"

In the above example, some_fixture is actually an instance of the SomeInterface class, even though it has "fixture" in the name. In this way, interface classes can easily be converted into fixtures.