diff --git a/.vscode/launch.json b/.vscode/launch.json
index 56952b1..1c237be 100644
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -4,6 +4,22 @@
     // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
     "version": "0.2.0",
     "configurations": [
+        {
+            "name": "Debug test script",
+            "type": "php",
+            "request": "launch",
+            "program": "",
+            "cwd": "${workspaceFolder}",
+            "port": 0,
+            "args": ["vendor/bin/phpunit", "${file}"],
+            "runtimeArgs": [
+                "-dxdebug.start_with_request=yes"
+            ],
+            "env": {
+                "XDEBUG_MODE": "debug,develop",
+                "XDEBUG_CONFIG": "client_port=${port}"
+            }
+        },
         {
             "name": "Launch currently open script",
             "type": "php",
diff --git a/Makefile b/Makefile
index 05fa947..16fc6f8 100644
--- a/Makefile
+++ b/Makefile
@@ -7,7 +7,7 @@ analyze-phpmd:
 analyze-phpstan:
 	vendor/bin/phpstan analyze --level=7  --error-format=raw src/ backup 
 analyze-psalm:
-	vendor/bin/psalm
+	vendor/bin/psalm --no-cache
 analyze-phpcs:
 	vendor/bin/phpcs src backup --report=emacs  --standard=PSR12
 
diff --git a/src/Notification/Ntfy.php b/src/Notification/Ntfy.php
index d9aeff2..ea71c0a 100644
--- a/src/Notification/Ntfy.php
+++ b/src/Notification/Ntfy.php
@@ -5,6 +5,8 @@ namespace App\Notification;
 use Ntfy\Server;
 use Ntfy\Message;
 use Ntfy\Client;
+use Exception;
+use InvalidArgumentException;
 
 class Ntfy implements NotificationInterface
 {
@@ -31,18 +33,30 @@ class Ntfy implements NotificationInterface
 
     public function setTopic(string $topic): void
     {
+        if (strlen($topic) < 1 || strlen($topic) >= 256) {
+            throw new InvalidArgumentException("Invalid topic length");
+        }
+
         $this->topic = $topic;
     }
 
+    public function getTopic(): string
+    {
+        return $this->topic;
+    }
+
     public function send(string $title, string $message): void
     {
-        assert(strlen($title) > 0);
-        assert(strlen($title) < 256);
-        assert(strlen($message) > 0);
-        assert(strlen($message) < 4096);
+        if (strlen($title) < 1 || strlen($title) >= 256) {
+            throw new InvalidArgumentException("Invalid title length");
+        }
+
+        if (strlen($message) < 1 || strlen($message) >= 4096) {
+            throw new InvalidArgumentException("Invalid message length");
+        }
 
         $msg = new Message();
-        $msg->topic($this->topic);
+        $msg->topic($this->getTopic());
         $msg->title($title);
         $msg->body($message);
         $this->client->send($msg);
diff --git a/tests/Notification/NtfyTest.php b/tests/Notification/NtfyTest.php
index 77cee4c..876c356 100644
--- a/tests/Notification/NtfyTest.php
+++ b/tests/Notification/NtfyTest.php
@@ -4,14 +4,77 @@ use PHPUnit\Framework\TestCase;
 use App\Notification\Ntfy;
 use Ntfy\Client;
 use Ntfy\Message;
+use PHPUnit\Framework\Attributes\DataProvider;
 
 final class NtfyTest extends TestCase
 {
+
+    private ?Ntfy $instance;
+
+    protected function setUp(): void
+    {
+        $this->client = $this->createMock(Client::class);
+        $this->instance = new Ntfy($this->client);
+    }
+
+    protected function tearDown(): void
+    {
+        $this->instance = null;
+    }
+
+    public function testFactory(): void
+    {
+        $config = ['domain'=>'https://test.com', 'topic'=>'something'];
+        $instance = Ntfy::factory($config);
+        $this->assertInstanceOf(Ntfy::class, $instance);
+    }
+
     public function testSend(): void
     {
-        $client = $this->createMock(Client::class);
-        $sut = new Ntfy($client);
-        $client->expects($this->once())->method('send')->with($this->isInstanceOf(Message::class));
-        $sut->send('title','text');
+        $this->client->expects($this->once())->method('send')->with($this->isInstanceOf(Message::class));
+        $this->instance->send('title','text');
+    }
+
+
+    public static function sendBadParameterProvider(): array
+    {
+        return [
+            ['', ''],
+            ['', 'text'],
+            ['title', ''],
+            [str_repeat("t", 256),'text'],
+            ['title',str_repeat("t", 4096)],
+        ];
+    }
+
+    #[DataProvider('sendBadParameterProvider')]
+    public function testSendInvalidParameters($title, $message): void
+    {
+        $this->expectException(InvalidArgumentException::class);
+        $this->instance->send($title, $message);
+    }
+
+    public function testSetTopic(): void
+    {
+        $topic = "abcdefg";
+        $this->instance->setTopic($topic);
+        $this->assertEquals($topic, $this->instance->getTopic());
+    }
+
+    public static function topicBadParameterProvider(): array
+    {
+        return [
+            [''],
+            [str_repeat("t", 256)],
+            [str_repeat("t", 4096)],
+        ];
+    }
+
+    #[DataProvider('topicBadParameterProvider')]
+    public function testSetTopicInvalidParameters( $topic ): void
+    {
+        $this->expectException(InvalidArgumentException::class);
+        $this->instance->setTopic( $topic );
+
     }
 }
\ No newline at end of file