added activity events for plugins (#2516)

tests/Event/AbstractActivityEventTest.php

@@ -0,0 +1,29 @@
+<?php
+
+/*
+ * This file is part of the Kimai time-tracking app.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace App\Tests\Event;
+
+use App\Entity\Activity;
+use App\Event\AbstractActivityEvent;
+use PHPUnit\Framework\TestCase;
+use Symfony\Contracts\EventDispatcher\Event;
+
+abstract class AbstractActivityEventTest extends TestCase
+{
+    abstract protected function createActivityEvent(Activity $activity): AbstractActivityEvent;
+
+    public function testGetterAndSetter()
+    {
+        $activity = new Activity();
+        $sut = $this->createActivityEvent($activity);
+
+        self::assertInstanceOf(Event::class, $sut);
+        self::assertSame($activity, $sut->getActivity());
+    }
+}