I like this work a lot. It's good to give developers easy to verify
guidance about formatting the --help messages.
However, I think instead of just adding a bunch of line breaks to
satisfy the test, we should really try to make the lines shorter by
rewording. Otherwise, chances are we are making the usability worse for
many users, because it's more likely that part of the help will scroll
off the screen. For example, in many cases, we could replace "do not"
by "don't", or we could decrease the indentation of the second column by
a few spaces, or just reword altogether.
Also, it would be very useful if the TAP test function could print out
the violating lines if a test fails. (Similar to how is() and like()
print the failing values.) Maybe start with that, and then it's easier
to play with different wording variants to try to make it fit better.