Add tests with 100% coverage for new GraphProperty algorithm

Author: clue

tests/Property/PropertyGraphTest.php

@@ -0,0 +1,27 @@
+<?php
+
+use Fhaculty\Graph\Graph;
+use Fhaculty\Graph\Algorithm\Property\GraphProperty;
+
+class PropertyGraphTest extends TestCase
+{
+    public function testEmptyIsEdgeless()
+    {
+        $graph = new Graph($graph);
+
+        $alg = new GraphProperty($graph);
+
+        $this->assertTrue($alg->isEdgeless());
+        $this->assertFalse($alg->isTrivial());
+    }
+
+    public function testSingleVertexIsTrivial()
+    {
+        $graph = new Graph();
+        $graph->createVertex(1);
+
+        $alg = new GraphProperty($graph);
+
+        $this->assertTrue($alg->isTrivial());
+    }
+}