Resolved issue #5

Author: peter279k

.travis.yml

@@ -1,5 +1,5 @@
 language: php
-dist: trusty
+dist: xenial
 sudo: true
 php:
   - '7.1'

src/Encryption.php

@@ -16,6 +16,8 @@
 
 namespace Lablnet;
 
+use InvalidArgumentException;
+
 class Encryption
 {
     /**
@@ -86,6 +88,10 @@ public function setAdapter($adapter)
      */
     public function setKey($key)
     {
+        if ($key === '') {
+            throw new InvalidArgumentException('The key should not be empty string.');
+        }
+
         $this->key = $key;
 
         return $this;

tests/EncryptionTest.php

@@ -16,6 +16,7 @@
 
 namespace Lablnet\Tests;
 
+use InvalidArgumentException;
 use Lablnet\Encryption;
 use PHPUnit\Framework\TestCase;
 
@@ -42,4 +43,11 @@ public function testEncryptAndDecryptWithSodium()
         $this->assertSame(112, strlen($encryptedString));
         $this->assertSame('plain-text', $decryptedString);
     }
+
+    public function testEncryptOnEmptyStringKey()
+    {
+        $this->expectException(InvalidArgumentException::class);
+
+        new Encryption('', 'sodium');
+    }
 }