Improve array validation message

[s3bsch]

The available validation rules in Laravel are awesome and most of the time the error message which is shown to the client is super clear and helpful.

But recently I had a finding related to the array validation rule, which made me think. Can this be improved? 🤔

When you are using the array validation rule with extra arguments, like it is also shown in the documentation, then you get a rather confusing error message.

test('validation message of array rule', function () {
    $input = [
        'user' => [
            'name' => 'Taylor Otwell',
            'username' => 'taylorotwell',
            'admin' => true,
        ],
    ];

    $validator = Validator::make($input, [
        'user' => 'array:name,username',
    ]);

    dump($validator->messages());
    # → The user field must be an array.
});

The user in the input is clearly an array. But it defines additional attributes which are not expected/allowed.

For me this is not this 100% Laravel usually tries to deliver. Does anybody think the same? It did not dare to open a bug issue for this, as I would not really consider this as a "bug". It's more an enhancement.

I found out that the message is defined in src/Illuminate/Translation/lang/en/validation.php#L24. Does anybody have a glue how "easy" this could be improved? Or if this is even possible at all?

[macropay-solutions]

Acc. to ->validated() return type, it should return only user as array with name and username. If it is not acting like that then you could say it is not like laravel works/should work.

Update:

But clearly is marks the user as invalid because it does have other attributes which is ok, no?

The only thing missing here is the message that does not clearly explain the reason.

[s3bsch]

The behavior is totally fine, it's just the message that does bother me.

Imagine you are working on a client calling this API endpoint and you get this message back. It does not explain what is actually wrong.

[macropay-solutions]

\Illuminate\Validation\Concerns\ValidatesAttributes::validateArray

    /**
     * Validate that an attribute is an array.
     *
     * @param  string  $attribute
     * @param  mixed  $value
     * @param  array  $parameters
     * @return bool
     */
    public function validateArray($attribute, $value, $parameters = [])
    {
        if (! is_array($value)) {
            return false;
        }

        if (empty($parameters)) {
            return true;
        }

        return empty(array_diff_key($value, array_fill_keys($parameters, '')));
    }

as you can see the function returns only bool and then the default message is used. Throwing an exception with the message from there would mean some refactoring...

[macropay-solutions]

You could use manual message to overwrite the default one, or a custom rule...

[s3bsch]

Thanks for the suggestion, which is really a good one. I already defined a custom message and solved this for our API.

But my intention was more to improve the framework (if possible) for the whole community. I can not imagine we are the only ones stumbling over this.

In case anybody else see an improvement here I'm open to create a pull request for this. Before spending more time and going deeper, I thought starting a discussion makes sense. 😊