Add tests for setRemberMeExpire()

tests/lib/SimpleSAML/SessionTest.php

+<?php
+
+declare(strict_types=1);
+
+namespace SimpleSAML\Test\Utils;
+
+use PHPUnit\Framework\TestCase;
+use SimpleSAML\Test\Utils\ClearStateTestCase;
+use SimpleSAML\Session;
+use SimpleSAML\Configuration;
+
+class SessionTest extends ClearStateTestCase
+{
+    /** @var \SimpleSAML\Session */
+    protected $session;
+
+    /**
+     * @return void
+     */
+    public function setUp(): void
+    {
+        $this->session = Session::getSessionFromRequest();
+    }
+
+    /**
+     * @return void
+     */
+    public function testSetRememberMeExpireDefaults(): void
+    {
+        // Not yet set
+        $this->assertNull($this->session->getRememberMeExpire());
+
+        // Set to default value
+        $this->session->setRememberMeExpire();
+
+        $this->assertEquals(time() + 14 * 86400, $this->session->getRememberMeExpire());
+    }
+
+    /**
+     * @return void
+     */
+    public function testSetRememberMeExpireExplicit(): void
+    {
+        // Set to specific value
+        $this->session->setRememberMeExpire(1000);
+
+        $this->assertEquals(time() + 1000, $this->session->getRememberMeExpire());
+    }
+}