Convert more controller tests to request tests

tests/integration/api/groups/ListTest.php

@@ -0,0 +1,31 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Tests\integration\api\groups;
+
+use Flarum\Group\Group;
+use Flarum\Tests\integration\TestCase;
+
+class ListTest extends TestCase
+{
+    /**
+     * @test
+     */
+    public function shows_index_for_guest()
+    {
+        $response = $this->send(
+            $this->request('GET', '/api/groups')
+        );
+
+        $this->assertEquals(200, $response->getStatusCode());
+        $data = json_decode($response->getBody()->getContents(), true);
+
+        $this->assertEquals(Group::count(), count($data['data']));
+    }
+}