[11.x] Introduce method Rule::array()

[Jacobs63]

This PR introduces a new array method to \Illuminate\Validation\Rule.

Currently, it is often cumbersome to validate multiple array keys through the array rule. At the same time, if intending to using constants, or enums, we may end up in defining our rule such as:

['array:' . MyBackedEnum::VALUE->value . ',' . MyBackedEnum::VALUE_2->value]

The goal of this change is to improve code readability and prevent uncaught typos when validating array keys, but to also improve the existing functionalities by introducing support for Arrayable & lists of enums.

The newly introduced ArrayRule works very similar to the already existing In rule, by stringifying to the original array string rule, introducing no breaking changes.

In summary, the following is now possible:

Rule::array();

Rule::array('key_1', 'key_2', 'key_3');

Rule::array(['key_1', 'key_2', 'key_3']);

Rule::array(collect(['key_1', 'key_2', 'key_3']));

Rule::array([UnitEnum::key_1, UnitEnum::key_2, UnitEnum::key_3]);

Rule::array([BackedEnum::key_1, BackedEnum::key_2, BackedEnum::key_3]);

[vaishnavyogesh]

@Jacobs63 why not use Rule::enum() for matching against an enum's cases?

[Jacobs63]

@Jacobs63 why not use Rule::enum() for matching against an enum's cases?

The array rule does not serve for validating values, it can either validate, that:

1. The input value is of type array
2. The input value is of type array and only contains specific keys

Unlike enum rule, which validates values and can validate that:

1. The input value matches the enum name (if UnitEnum)
2. The input value matches the enum value (if BackedEnum)

They're two different validation rules.

[vaishnavyogesh]

@Jacobs63 why not use Rule::enum() for matching against an enum's cases?

The array rule does not serve for validating values, it can either validate, that:

1. The input value is of type array
2. The input value is of type array and only contains specific keys

Unlike enum rule, which validates values and can validate that:

1. The input value matches the enum name (if UnitEnum)
2. The input value matches the enum value (if BackedEnum)

They're two different validation rules.

My bad! I misunderstood the usecase, thanks for the explaination though.

[osbre]

What's the difference between Rule::in and Rule::array? Why another method?

[decadence]

What's the difference between Rule::in and Rule::array? Why another method?

array defines keys that validated value (array) can have. in is list of allowed values for validated value.

[osbre]

@decadence Thank you. I wasn't aware there's already an array rule in the first place 😅

https://laravel.com/docs/11.x/validation#rule-array