Sanity checking phone number via Beberlei\Assertion::e164() worth it?

[Revisor]

The ApiSmsManager checks whether recipients' phone numbers follow the E.164 recommendation (lines 98 - 102):

foreach ($smsMessage->getRecipients() as $recipient) {
    Assertion::e164($recipient);
    $numberList->addChild('Number', $recipient);
    $hasAnyNumber = true;
}

It does this by pulling the whole Beberlei/Assert library and calling the method \Assert\Assertion::e164(), which by itself is nothing more than a small regex:

if (!\preg_match('/^\+?[1-9]\d{1,14}$/', $value))

My questions:

1. Is it worth it pulling down a whole library just for one regex? Maybe it would be better to drop the dependency and just check this manually, with your own method.
2. The E.164 is just a recommendation and it doesn't get followed. See Falsehood about phone numbers nr. 15:

ITU-T specifies that a phone number cannot be longer than fifteen digits, with one to three digits reserved for the country calling code, but valid numbers in Germany have been assigned that are longer than this.

Maybe this library could drop the Assertion dependency and just loosely sanity-check whether the given number looks like a phone number, something like

if ( ! preg_match('/^\+?\d+$/', $phoneNumber))

Checking if the number is a real phone number (let alone one which can receive SMS) is much more complicated and there is a whole huge library for it, so I would leave it out.

What do you think?

[simPod]

Hi @Revisor. First, thank you for exhausting issue!

I completely agree with you. Simple regex check sounds reasonable, I'd leave the rest of validation responsibility to SMS Gateway backend. Care sending PR?

Best! S.