InvoiceShelf/app/Policies/UserPolicy.php

<?php

namespace App\Policies;

use App\Models\User;
use Illuminate\Auth\Access\HandlesAuthorization;

class UserPolicy
{
    use HandlesAuthorization;

    /**
     * Determine whether the user can view any models.
     *
     * @return mixed
     */
    public function viewAny(User $user): bool
    {
        if ($user->isOwner()) {
            return true;
        }

        return false;
    }

    /**
     * Determine whether the user can view the model.
     *
     * @return mixed
     */
    public function view(User $user, User $model): bool
    {
        return $user->isOwner() && $this->sharesActiveCompany($model);
    }

    /**
     * Determine whether the user can create models.
     *
     * @return mixed
     */
    public function create(User $user): bool
    {
        if ($user->isOwner()) {
            return true;
        }

        return false;
    }

    /**
     * Determine whether the user can update the model.
     *
     * @return mixed
     */
    public function update(User $user, User $model): bool
    {
        return $user->isOwner() && $this->sharesActiveCompany($model);
    }

    /**
     * Determine whether the user can delete the model.
     *
     * @return mixed
     */
    public function delete(User $user, User $model): bool
    {
        return $user->isOwner() && $this->sharesActiveCompany($model);
    }

    /**
     * Determine whether the user can restore the model.
     *
     * @return mixed
     */
    public function restore(User $user, User $model): bool
    {
        if ($user->isOwner()) {
            return true;
        }

        return false;
    }

    /**
     * Determine whether the user can permanently delete the model.
     *
     * @return mixed
     */
    public function forceDelete(User $user, User $model): bool
    {
        if ($user->isOwner()) {
            return true;
        }

        return false;
    }

    /**
     * Determine whether the user can invite the model.
     *
     * @return mixed
     */
    public function invite(User $user, User $model)
    {
        if ($user->isOwner()) {
            return true;
        }

        return false;
    }

    /**
     * Determine whether the user can delete models.
     *
     * @return mixed
     */
    public function deleteMultiple(User $user)
    {
        if ($user->isOwner()) {
            return true;
        }

        return false;
    }

    /**
     * A company owner may only act on members of the company set in the
     * `company` request header. Without this, view/update/delete resolve the
     * target user by global id, which would let an owner of one company read
     * or overwrite users belonging to another company (cross-tenant IDOR).
     */
    private function sharesActiveCompany(User $model): bool
    {
        $companyId = request()->header('company');

        return $companyId
            && $model->companies()->wherePivot('company_id', $companyId)->exists();
    }
}