Make AbstractPolicy compatible with both object and class as $model (#1977)

tests/unit/User/AbstractPolicyTest.php

@@ -0,0 +1,48 @@
+<?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\unit\User;
+
+use Flarum\Event\GetPermission;
+use Flarum\Tests\unit\TestCase;
+use Flarum\User\User;
+use Illuminate\Events\Dispatcher;
+use Mockery as m;
+
+class AbstractPolicyTest extends TestCase
+{
+    private $policy;
+    private $dispatcher;
+
+    public function setUp()
+    {
+        $this->policy = m::mock(UserPolicy::class)->makePartial();
+        $this->dispatcher = new Dispatcher();
+        $this->dispatcher->subscribe($this->policy);
+        User::setEventDispatcher($this->dispatcher);
+    }
+
+    public function test_policy_can_be_called_with_object()
+    {
+        $this->policy->shouldReceive('edit')->andReturn(true);
+
+        $allowed = $this->dispatcher->until(new GetPermission(new User(), 'edit', new User()));
+
+        $this->assertTrue($allowed);
+    }
+
+    public function test_policy_can_be_called_with_class()
+    {
+        $this->policy->shouldReceive('create')->andReturn(true);
+
+        $allowed = $this->dispatcher->until(new GetPermission(new User(), 'create', User::class));
+
+        $this->assertTrue($allowed);
+    }
+}