javascript - Laravel validation with vuex store always responded error 422

Solution:

this code will only work when you will validate one country per post:

 $this->validate($request, ['iso' => 'required']);

But you are storing n countries, so you will have to validate the array:

$this->validate($request, ['countries.*.iso' => 'required']);

Solution:

the problem is with your validation rules. When you write

$this->validate($request, ['iso' => 'required']);

it means that you request requires a field "iso" to be validated, and in your post

 axios.post('/api/countries/upsert',{
            countries: state.countries,
 })

you only have a "countries" prop and "iso" is considered empty so your required rules is always declined.

If you are trying to validate that every country in your countries array needs to have a required "iso" field you should check how to validate arrays here Laravel Arrays Validation