L-Ami-Fiduciaire/app/Http/Requests/StoreFolderMentionRequest.php

<?php

namespace App\Http\Requests;

use Illuminate\Foundation\Http\FormRequest;
use Illuminate\Validation\Rule;

class StoreFolderMentionRequest extends FormRequest
{
    /**
     * Determine if the user is authorized to make this request.
     */
    public function authorize(): bool
    {
        return $this->user() !== null;
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array<string, \Illuminate\Contracts\Validation\ValidationRule|array<mixed>|string>
     */
    public function rules(): array
    {
        $workspaceId = $this->session()->get('current_workspace_id');

        return [
            'user_id' => [
                'required',
                'integer',
                Rule::exists('workspace_user', 'user_id')
                    ->where('workspace_id', $workspaceId),
            ],
            'message' => ['required', 'string', 'max:500'],
        ];
    }
}