Empty sparse fieldset parameter returns 500 error

[mdpoulter]

When providing an empty value to any of the fields query parameters, the server returns a 500 error with server error being:

LaravelJsonApi\Validation\Rules\AllowedFieldSets::notAllowed(): Argument # 2 ($fields) must be of type string, null given, called in /vendor/laravel-json-api/validation/src/Rules/AllowedFieldSets.php on line 232"

For example, if the client requests the following:

http://localhost/api/v1/employees?fields[employees]=

It certainly makes sense for an error to be returned, but I would have expected a validation error given that this is a client issue. It also ends up in our error tracking software which isn't great.

While not an ideal solution, I wondered if adding validation for each of the fields parameters (current resource and all relations) would help. Unfortunately, it still returns the same 500 error for the above request. For example:

'fields' => [
    'nullable',
    'array',
    JsonApiRule::fieldSets(),
],
'fields.employees' => 'filled',

[lindyhopchris]

Thanks for reporting. This does indeed look like a bug, so I'll get this fixed.

[lindyhopchris]

Out of interest, what do you expect the server to return when they've request no fields for the employees resource, as per that example?

[lindyhopchris]

Actually, have found the answer in the spec:

An empty value indicates that no fields should be returned.

So that would mean you only get the type and id - i.e. no attributes or relationships.

[mdpoulter]

Ah that's interesting! Thanks for investigating 😄

[lindyhopchris]

Tagged in 2.5.2 of this package. To update:

composer require laravel-json-api/laravel --no-update
composer up "laravel-json-api/*"

[mdpoulter]

Wow, that was fast - thank you so much!

[lindyhopchris]

Aha yeah you caught me on an evening when I was doing Laravel JSON:API admin!! 😄