Introduce a new harness based on pytest that does basic shell command
handling. The harness is enabeld using:
harness: shell
and expects a file with parameters in the form:
test_shell_harness:
- command: "kernel version"
expected: "Zephyr version .*"
- ...
Multiple commands and their expected output can be tested.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
