Use the run_test_suite script found in the Tails source root to run all automated Cucumber test features. See the setup documentation in case you don't have a testing environment yet.

It's important to note that some features only depend on the Tails sources, and some on the actual product of the sources, i.e. a Tails ISO image. These features are tagged @source and @product, respectively. The arguments passed to run_test_suite may only affect one of these types of features and not the other.

A typical example run of a few @product features could be:

./run_test_suite --view --capture test-0.17.webm \
    --iso path/to/tails.iso \
    features/apt.feature features/erase_memory.feature

which will test only the iceweasel and erase_memory features (if no feature paths are given, all features in features/cucumber will be tested) of the given ISO image tails.iso while showing the test session in a VNC viewer (--view) and also capturing it into a video called test-0.17.web (--capture). Similarly, to test a @source feature, we'd simply run something like:

./run_test_suite features/build.feature

For full instructions, see its --help.

Note: since the test suite itself uses virt-viewer to interact with the Tails guest you cannot use it as that will steal the session from the test suite, leaving it with a blank screen.