The openQA test suite for openSUSE and SLE has a test module called
tests/console/sudo.pm.
It verifies that sudo works: passwords, shells, sudoers rules,
environment isolation. Basic stuff. It runs tens of thousands of
times per year and takes about 9 minutes each time. That adds up.
Where the time goes
There is no single bottleneck. The test uses expect to interact
with password prompts. Every sudo call goes through credential cache
reset, process spawn, password entry, and result verification. It
does this 20 times because the test runs the full suite twice with
slightly different sudoers configurations.