[11.x] slug() with alphanumeric separator

[faissaloux]

Fixes #54444

This PR made slug() fallback to default separator (-) when an alphanumeric separator been passed.

Examples

Before

str('nad')->slug('az'); // nazd

After

str('nad')->slug('az'); // nad

str('hello world')->slug('e'); // hello-word
str('hello world')->slug('2'); // hello-word

[shaedrich]

I don't like these silent fallbacks that might not be intuitive and therefore easily overlooked when something doesn't work as expected. Maybe, throwing an exception is more intuitive.

[rodrigopedra]

I agree with @shaedrich, silent fallbacks are not intuitive at all.

And this approach also does not solve the issue described, as the issue reporter expects to be using a localized slug in a different language, and the proposed solution would mask the issue further as they would expect language-specific characters to be treated in that language.

For example, the word "soccer" in Russian is written as "футбольный" (according to Google Translate, I don't speak Russian). It would get different slugs depending on the language parameter:

$ php artisan tinker
Psy Shell v0.12.7 (PHP 8.2.27 — cli) by Justin Hileman
> str('футбольный')->slug()
= Illuminate\Support\Stringable {#6608
    value: "futbolnyi",
  }

> str('футбольный')->slug('ru')
= Illuminate\Support\Stringable {#6632
    value: "frutbolnyi",
  }

> str('футбольный')->slug('-')
= Illuminate\Support\Stringable {#6626
    value: "futbolnyi",
  }

> str('футбольный')->slug(language: 'ru')
= Illuminate\Support\Stringable {#6612
    value: "futbolnyy",
  }

Blindly replacing ru by - when the language parameter is not specified correctly would result in an unexpected slug, as outlined in the examples above.

I commented in the issue, recommending the user to use a named parameter to properly specify the language parameter:

#54444 (comment)

[vlakoff]

The use case is incorrect due to an erroneous parameter, and the proposed change would not solve the issue, but rather create additional problems. This should be closed as invalid.