Display empty or None help parameter for parser option as empty string

[hp310780]

In response to Bug #7394 , this PR updates pytest --help to parse an empty string or None as an empty string for the help parameter.

closes #7394

[gnikonorov]

Thanks for the PR @hp310780! I left some comments

Also, don't forget to add a changelog entry

[gnikonorov]

Requesting changes as above, sorry I checked approve on accident

[gnikonorov]

I was thinking something like [No description provided] so the end user knows the state of the option. But, happy to change to throwing an error (a TypeError like a missing function param?) on help being None or "", let me know what you would like.

Let’s get some more input. @RonnyPfannschmidt @nicoddemus do we think that in the event of no help provided we should throw an error, or supply a default help

[gnikonorov]

@hp310780 - I personally vote in favor of an exception. Are you ok with going with that plan while we wait for a review

[hp310780]

@hp310780 - I personally vote in favor of an exception. Are you ok with going with that plan while we wait for a review

Yep! Changed. Let me know of any feedback. Thanks.

[gnikonorov]

I think other than the comment I left the change looks good

[gnikonorov]

Thanks @hp310780, look good!

Let's wait for Ronny to take a look as well

[gnikonorov]

bump @RonnyPfannschmidt @nicoddemus @bluetech - could someone else take a look at this PR?

[bluetech]

Thanks for the update @hp310780. I left a couple of comments.

[nicoddemus]

LGTM, the requests/suggestions by @bluetech are on point! 👍

[bluetech]

Almost there, just one last question. I had hoped the improved test would answer it but it didn't.

[bluetech]

Thanks @hp310780! This looks good now. I will merge it right after pytest 6.0.0 is released (I don't want to interfere with the ongoing release).

[nicoddemus]

Backport: #7577