libinput ships with a number of tests all run automatically on ninja test.
The primary test suite is the libinput-test-suite-runner. When testing, the libinput-test-suite-runner should always be invoked to check for behavior changes.
The test suite runner uses Check underneath the hood but most of the functionality is abstracted into litest wrappers.
The test suite runner has a make-like job control enabled by the -j or --jobs flag and will fork off as many parallel processes as given by this flag. The default if unspecified is 8. When debugging a specific test case failure it is recommended to employ test filtures (see Selective running of tests) and disable parallel tests. The test suite automatically disables parallel make when run in gdb.
X.Org config to avoid interference
uinput devices created by the test suite are usually recognised by X as input devices. All events sent through these devices will generate X events and interfere with your desktop.
Copy the file $srcdir/test/50-litest.conf into your /etc/X11/xorg.conf.d and restart X. This will ignore any litest devices and thus not interfere with your desktop.
Permissions required to run tests
Most tests require the creation of uinput devices and access to the resulting /dev/input/eventX nodes. Some tests require temporary udev rules. This usually requires the tests to be run as root. If not run as root, the test suite runner will exit with status 77, interpreted as "skipped" by ninja.
Selective running of tests
litest's tests are grouped into test groups, test names and devices. A test group is e.g. "touchpad:tap" and incorporates all tapping-related tests for touchpads. Each test function is (usually) run with one or more specific devices. The --list commandline argument shows the list of suites and tests. This is useful when trying to figure out if a specific test is run for a device.
In the above example, the "pointer:left-handed" suite contains multiple tests, e.g. "pointer_left_handed_during_click" (this is also the function name of the test, making it easy to grep for). This particular test is run for various devices including the trackpoint device and the magic mouse device.
The "no device" entry signals that litest does not instantiate a uinput device for a specific test (though the test itself may instantiate one).
The --filter-test argument enables selective running of tests through basic shell-style function name matching. For example:
The --filter-device argument enables selective running of tests through basic shell-style device name matching. The device names matched are the litest-specific shortnames, see the output of --list. For example:
The --filter-group argument enables selective running of test groups through basic shell-style test group matching. The test groups matched are litest-specific test groups, see the output of --list. For example:
The --filter-device and --filter-group arguments can be combined with --list to show which groups and devices will be affected.
Controlling test output
Each test supports the --verbose commandline option to enable debugging output, see libinput_log_set_priority() for details. The LITEST_VERBOSE environment variable, if set, also enables verbose mode.
