Add FunctionalTest to test both Exporter and Loader

Author: clue

tests/FunctionalTest.php

@@ -0,0 +1,27 @@
+<?php
+
+use Fhaculty\Graph\Graph;
+use Graphp\GraphML\Exporter;
+use Graphp\GraphML\Loader;
+
+class FunctionalTest extends TestCase
+{
+    public function testMixed()
+    {
+        // 1 -- 2 -> 3
+        $graph = new Graph();
+        $v1 = $graph->createVertex(1);
+        $v2 = $graph->createVertex(2);
+        $v3 = $graph->createVertex(3);
+        $v1->createEdge($v2);
+        $v2->createEdgeTo($v3);
+
+        $exporter = new Exporter();
+        $output = $exporter->getOutput($graph);
+
+        $loader = new Loader();
+        $new = $loader->loadContents($output);
+
+        $this->assertGraphEquals($graph, $new);
+    }
+}