Keep only 100 notifications per user.

Author: alexsegura

src/MessageHandler/TopBarNotificationHandler.php

@@ -14,6 +14,8 @@ class TopBarNotificationHandler
     private $redis;
     private $liveUpdates;
 
+    public const MAX_NOTIFICATIONS = 100;
+
     public function __construct(
         Redis $redis,
         LiveUpdates $liveUpdates)
@@ -37,8 +39,15 @@ public function __invoke(TopBarNotification $message)
                 'timestamp' => (new \DateTime())->getTimestamp()
             ];
 
-            $this->redis->lpush($listKey, $uuid);
-            $this->redis->hset($hashKey, $uuid, json_encode($payload));
+            $this->redis->lPush($listKey, $uuid);
+            $this->redis->hSet($hashKey, $uuid, json_encode($payload));
+
+            $length = $this->redis->lLen($listKey);
+            if ($length > self::MAX_NOTIFICATIONS) {
+                $itemsToRemove = $this->redis->lRange($listKey, self::MAX_NOTIFICATIONS, $length - 1);
+                $this->redis->lTrim($listKey, 0, self::MAX_NOTIFICATIONS - 1);
+                $this->redis->hDel($hashKey, ...$itemsToRemove);
+            }
 
             $notificationsPayload = [
                 'name' => 'notifications',

tests/AppBundle/MessageHandler/TopBarNotificationHandlerFunctionalTest.php

@@ -0,0 +1,81 @@
+<?php
+
+namespace Tests\AppBundle\MessageHandler;
+
+use AppBundle\Message\TopBarNotification;
+use AppBundle\MessageHandler\TopBarNotificationHandler;
+use AppBundle\Service\LiveUpdates;
+use Prophecy\PhpUnit\ProphecyTrait;
+use Ramsey\Uuid\Uuid;
+use Redis;
+use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
+
+class TopBarNotificationHandlerFunctionalTest extends KernelTestCase
+{
+    private $redis;
+    private $liveUpdates;
+
+    use ProphecyTrait;
+
+    public function setUp(): void
+    {
+        parent::setUp();
+
+        self::bootKernel();
+
+        $this->redis = self::getContainer()->get(Redis::class);
+        $this->liveUpdates = $this->prophesize(LiveUpdates::class);
+    }
+
+    public function tearDown(): void
+    {
+        $this->redis->del('user:bob:notifications');
+        $this->redis->del('user:bob:notifications_data');
+
+        parent::tearDown();
+    }
+
+    public function testNotificationsLimit()
+    {
+        $handler = new TopBarNotificationHandler(
+            $this->redis,
+            $this->liveUpdates->reveal()
+        );
+
+        for ($i = 0; $i < 500; $i++) {
+            $message = new TopBarNotification(['bob'], 'Lorem ipsum');
+            call_user_func_array($handler, [$message]);
+        }
+
+        $this->assertEquals(TopBarNotificationHandler::MAX_NOTIFICATIONS, $this->redis->llen('user:bob:notifications'));
+        $this->assertEquals(TopBarNotificationHandler::MAX_NOTIFICATIONS, $this->redis->hlen('user:bob:notifications_data'));
+    }
+
+    public function testNotificationsLimitWithExisting()
+    {
+        $handler = new TopBarNotificationHandler(
+            $this->redis,
+            $this->liveUpdates->reveal()
+        );
+
+        for ($i = 0; $i < 500; $i++) {
+
+            $uuid = Uuid::uuid4()->toString();
+
+            $payload = [
+                'id' => $uuid,
+                'message' => 'Lorem ipsum',
+                'timestamp' => (new \DateTime())->getTimestamp()
+            ];
+
+            $this->redis->lPush('user:bob:notifications', $uuid);
+            $this->redis->hSet('user:bob:notifications_data', $uuid, json_encode($payload));
+        }
+
+        $message = new TopBarNotification(['bob'], 'Lorem ipsum');
+        call_user_func_array($handler, [$message]);
+
+        $this->assertEquals(TopBarNotificationHandler::MAX_NOTIFICATIONS, $this->redis->llen('user:bob:notifications'));
+        $this->assertEquals(TopBarNotificationHandler::MAX_NOTIFICATIONS, $this->redis->hlen('user:bob:notifications_data'));
+    }
+}