Maybe I don't understand what this lines does, but...

[joedevon]

$rules = (isset($options['rules']['rule'])) ? array($options['rules']) : $options['rules'];

So if $options['rules']['rule'] exists, which means $options['rules'] is an array, then cast $options['rules'] to an array and pass that value to $rules.

Otherwise, clearly $options['rules'] is not an array, therefore just pass it to $rules.

Isn't that the same as:

$rules = $options['rules']

?

Am I missing something?

(Sometimes my tone gets misunderstood on the Internet so to be clear, I'm not being snarky. Just want to clarify.)

[tmaiaroto]

It's ok! I appreciate the enthusiasm and interest. You can fork this and submit a pull request / patch if you like. I'm super swamped and just can't get to all the things I'd like to unfortunately. Thanks for your feedback.

[joedevon]

No need to. I read it wrong.

It isn't casting to an array, it's just adding it to an empty array.
Not totally clear why you're doing it (yet), but after some testing I can see that there was a purpose there.

[tmaiaroto]

You know, it's been a while, but all that I can remember (fuzzy) is that I wanted to allow it to accept a single rule or multiple...Each rule itself is an array though.