Unique rule has an issue with SORT_REGULAR flag

[dvdheiden]

Let's say we want to validate an array with SemVer numbers:

$array = [
    "14.0",
    "14.1",
    "14.10",
];

These are unique, and array_unique agrees with me:

array_unique($array);

Results in:

[
    "14.0",
    "14.1",
    "14.10",
]

But the unique rule in this package uses an additional flag, called SORT_REGULAR. According to the PHP docs:

SORT_REGULAR - compare items normally (don't change types)

So based on that it makes sense to use the flag. But unfortunately, it doesn't...

array_unique($array, SORT_REGULAR):

Results in:

[
    "14.0",
    "14.1",
]

As you can see 14.1 and 14.10 are considered the same. That's because SORT_REGULAR triggers a loose comparison, see: https://stackoverflow.com/a/14803087.

With loose comparison:

"14.1" == "14.10";

Results in true, but with strict comparison:

"14.1" === "14.10"

Results in false.

That's why I think we shouldn't use the SORT_REGULAR flag, but just the regular array_unique. Please let me know if there are some other considerations.

There are multiple solutions:

1. Provide the flag as parameter and default to SORT_REGULAR flag.
2. Drop the SORT_REGULAR flag.
3. Something else I can't think of right now 🤔

I'm willing to create a PR for this, so just let me know.

[henriquemoody]

Hi @dvdheiden !

I totally agree with you that we have a bug here. I'm inclined to DROP the flag altogether, unless there's a good reason not to. If you would be up for creating a pull request, I would be happy to review and merge it!

🐼

[dvdheiden]

Thanks for your reply. I will create a PR for it.

[dvdheiden]

Done, see: #1534