fix pdf export cache directory (#650)

tests/Utils/MPdfConverterTest.php

@@ -0,0 +1,37 @@
+<?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\Utils;
+
+use App\Utils\MPdfConverter;
+use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
+
+/**
+ * @covers \App\Utils\MPdfConverter
+ */
+class MPdfConverterTest extends KernelTestCase
+{
+    function unicode_hex($unicode_dec)
+    {
+        return (sprintf("%05s", strtoupper(dechex($unicode_dec))));
+    }
+
+    public function test()
+    {
+        $kernel = self::bootKernel();
+        $cacheDir = $kernel->getContainer()->getParameter('kernel.cache_dir');
+
+        $sut = new MPdfConverter($cacheDir);
+        $result = $sut->convertToPdf('<h1>Test</h1>');
+        // Yeah, thats not a real test, I know ;-)
+        $this->assertNotEmpty($result);
+        preg_match('/\/Creator \((.*)\)/', $result, $matches);
+        $this->assertCount(2, $matches);
+    }
+}