Run API Client requests through middleware (#2783)

- Add integration tests for login and registration
- Use URL instead of controller
- Add fluent API
- Allow setting parent request, user, session

tests/integration/forum/IndexTest.php

@@ -0,0 +1,72 @@
+<?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\forum;
+
+use Flarum\Extend;
+use Flarum\Testing\integration\RetrievesAuthorizedUsers;
+use Flarum\Testing\integration\TestCase;
+
+class IndexTest extends TestCase
+{
+    use RetrievesAuthorizedUsers;
+
+    /**
+     * @inheritDoc
+     */
+    protected function setUp(): void
+    {
+        $this->extend(
+            (new Extend\Csrf)->exemptRoute('login')
+        );
+
+        $this->prepareDatabase([
+            'users' => [
+                $this->normalUser()
+            ]
+        ]);
+    }
+
+    /**
+     * @test
+     */
+    public function guest_not_serialized_by_current_user_serializer()
+    {
+        $response = $this->send(
+            $this->request('GET', '/')
+        );
+
+        $this->assertEquals(200, $response->getStatusCode());
+        $this->assertStringNotContainsString('preferences', $response->getBody()->getContents());
+    }
+
+    /**
+     * @test
+     */
+    public function user_serialized_by_current_user_serializer()
+    {
+        $login = $this->send(
+            $this->request('POST', '/login', [
+                'json' => [
+                    'identification' => 'normal',
+                    'password' => 'too-obscure'
+                ]
+            ])
+        );
+
+        $response = $this->send(
+            $this->request('GET', '/', [
+                'cookiesFrom' => $login
+            ])
+        );
+
+        $this->assertEquals(200, $response->getStatusCode());
+        $this->assertStringContainsString('preferences', $response->getBody()->getContents());
+    }
+}