libinput test suite

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.

$ ./test/libinput-test-suite-runner --list
...
pointer:left-handed:
pointer_left_handed_during_click_multiple_buttons:
trackpoint
ms-surface-cover
mouse-wheelclickcount
mouse-wheelclickangle
low-dpi-mouse
mouse-roccat
mouse-wheel-tilt
mouse
logitech-trackball
cyborg-rat
magicmouse
pointer_left_handed_during_click:
trackpoint
ms-surface-cover
mouse-wheelclickcount
mouse-wheelclickangle
low-dpi-mouse
mouse-roccat
mouse-wheel-tilt
mouse
logitech-trackball
cyborg-rat
litest-magicmouse-device
pointer_left_handed:
trackpoint
ms-surface-cover
mouse-wheelclickcount
mouse-wheelclickangle
low-dpi-mouse
mouse-roccat
mouse-wheel-tilt
mouse
...

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:

$ ./test/libinput-test-suite-runner --filter-test="*1fg_tap*"

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:

$ ./test/libinput-test-suite-runner --filter-device="synaptics*"

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:

$ ./test/libinput-test-suite-runner --filter-group="touchpad:*hover*"

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.

$ ./test/libinput-test-suite-runner --verbose
$ LITEST_VERBOSE=1 ninja test