FormRequest failed validation returns 500 error instead of 422 with errors (after 5.2 upgrade)

Question

After updating from L5.1 to L5.2, I no longer receive a JSON object as response on a failed FormRequest (i.e. on an AJAX post request).

Usually I would receive a 422 response like:

[
    email: 'E-mail is invalid',
    firstname: 'Firstname must be at least 2 characters'
]

But now I receive a 500 error page:

I have ensured that my AJAX calls have application/json as Accept header.

Update

And no, I am not manually catching this exception. I am using the default FormRequest that Laravel provides. As they state in documentation: When using the validate method during an AJAX request, Laravel will not generate a redirect response. Instead, Laravel generates a JSON response containing all of the validation errors. This JSON response will be sent with a 422 HTTP status code.

Like so: php artisan make:request StoreBlogPostRequest (https://laravel.com/docs/5.1/validation#form-request-validation)

Answer 1

@Mattias!

I've recently had the same issue and I wasted more than 2 hours trying to understand what actually causes this problem. Disabling debugging in .env file causes form validation to display 500 since the FormValidator throws ValidationException (and it is unhandled). The solution for this issue was: Open app\Exceptions\Handler.php

private function handleExceptions($e)
    {
       // Add anywhere in this method the following code
       // It does what the FormValidator does.

        if($e instanceof ValidationException) {

            return redirect()->back()->withErrors($e->validator->getMessageBag()->toArray());
        }

        return response()->view('errors.500', [], 500);
    }

Answer 2

To reiterate what the others have said, you more than likely have a modified app/Exceptions/Handler.php in your project where you have some code that is preventing you from seeing the result you'd hoped for.

All exceptions are handled by the App\Exceptions\Handler class. This class contains two methods: report and render.

Double check app/Exceptions/Handler.php and the documentation regarding exception handlers at https://laravel.com/docs/5.2/errors#the-exception-handler to make sure you're handling exceptions as you'd intended.