adds api controller tests

tests/Api/Controller/ApiControllerTestCase.php

@@ -0,0 +1,46 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * (c) Toby Zerner <toby.zerner@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Flarum\Tests\Api\Controller;
+
+use Flarum\Http\Controller\ControllerInterface;
+use Flarum\Tests\Test\TestCase;
+use Flarum\User\User;
+use Psr\Http\Message\ResponseInterface;
+
+abstract class ApiControllerTestCase extends TestCase
+{
+    /**
+     * @var ControllerInterface
+     */
+    protected $controller;
+
+    /**
+     * @var null|User
+     */
+    protected $actor = null;
+
+    protected function callWith(array $body = []): ResponseInterface
+    {
+        return $this->call(
+            $this->controller,
+            $this->actor,
+            [],
+            $body ? ['data' => ['attributes' => $body]] : []
+        );
+    }
+
+    protected function tearDown()
+    {
+        $this->actor = null;
+        parent::tearDown();
+    }
+}