sprint_planer_web/tests/Controllers/UserControllerTest.php

<?php

declare(strict_types=1);

namespace App\Tests\Controllers;

use App\Controllers\UserController;
use PHPUnit\Framework\Attributes\DataProvider;
use PHPUnit\Framework\TestCase;

/**
 * The demotion guardrails are extracted into a pure static method; this
 * test pins the rule matrix without any SessionGuard / PDO setup.
 */
final class UserControllerTest extends TestCase
{
    /** @return list<array{int,int,bool,bool,int,?string,string}> */
    public static function guardrailCases(): array
    {
        // [actorId, targetId, wasAdmin, willBeAdmin, totalAdmins, expected, label]
        return [
            [1, 1, true,  false, 2, 'self_demote', 'self demote, 2 admins'],
            [1, 1, true,  false, 1, 'self_demote', 'self demote, only admin — self wins priority'],
            [1, 2, true,  false, 1, 'last_admin',  'demote the only admin (different user)'],
            [1, 2, true,  false, 2, null,          'demote someone else when another admin remains'],
            [1, 2, false, true,  1, null,          'promote — never blocked'],
            [1, 2, true,  true,  1, null,          'no-op — never blocked'],
            [1, 2, false, false, 1, null,          'no-op on non-admin — never blocked'],
            [1, 1, false, true,  1, null,          'actor promoting themselves? odd but not blocked'],
        ];
    }

    #[DataProvider('guardrailCases')]
    public function testDemoteGuardrail(
        int $actor,
        int $target,
        bool $was,
        bool $will,
        int $total,
        ?string $expected,
        string $label,
    ): void {
        $this->assertSame(
            $expected,
            UserController::demoteGuardrail($actor, $target, $was, $will, $total),
            $label,
        );
    }
}