Just a simple example of model constant testing via PHPUnit

UserConstantsTest.php

<?php

namespace Tests\Unit\Models;

use App\Models\User;
use PHPUnit\Framework\TestCase;

class UserConstantsTest extends TestCase
{
    /**
     * Test values of very important constants to avoid changes without notion.
     *
     * @return void
     */
    public function test_constants_of_role_ids_not_changed_values()
    {
        $this->assertTrue(1 === User::ROLE_ID_ADMIN);
        $this->assertTrue(2 === User::ROLE_ID_SUPPORTER);
        $this->assertTrue(3 === User::ROLE_ID_USER);
    }
}