User a Blender wrapper `tests/utils/blender_headless.py` to runs a
graphical instance of Blender within a headless weston compositor.
Currently only WAYLAND is supported as a back-end, support for other
platforms is possible. The tests can run from X11 since the tests don't
depend on existing instances of X11 or WAYLAND.
- Each test runs a separate headless instance of WESTON
since the overhead is minimal, this allows tests to run in parallel
without interfering with each other.
- There is a CMake option WESTON_BIN, when left empty the weston
from LIBDIR is used. Otherwise this can point to the weston binary
installed on the users system.
- In most cases simulated events are needed to implement these tests
(running blender with `--enable-event-simulate`).
- This commit adds 14 undo tests - simulating user interaction as well
as undo/redo actions, ensuring the desired result is reached.
Other kinds of UI tests could be added in the future.
Ref !114164
126f3bcfc1