Protect / help avoid validation logic problems

The problem was that the regex strings needed prefix and suffix slashes, but the UI didn't make that clear, once I added the slashes it worked as expected.

Turning this around to focus on improving the UI, it was user error that could be guarded against rather than a bug in the module.

100% agreed with this, regex validators should be... validated, both indicating the format expected and preventing saving the wrong format. Or just removing the need to append the slashes.

I guess I had the same issue here...

Migrated several regex rules from D7 to D10 and wondered why they all erroring with preg_match(): No ending delimiter '^. But https://stackoverflow.com/questions/4634993/php-regular-expressions-no-e... provided the solution. The D10 module requires leading and trailing slashes!

Example - Telephone number validation:

D7:
^(?:(\+\d{1,2})\s(?:\(\d{1,}\))\s(?:\d+[-.\s]?+)\d{1,})$

D10
/^(?:(\+\d{1,2})\s(?:\(\d{1,}\))\s(?:\d+[-.\s]?+)\d{1,})$/

Is this an intentional change or a defect in the module?