Improve the way graphs are compared using images.

Author: drupol

spec/drupol/phptree/Exporter/GraphSpec.php

@@ -6,9 +6,9 @@
 
 use drupol\phptree\Exporter\Graph;
 use drupol\phptree\Node\ValueNode;
-use PhpSpec\ObjectBehavior;
+use spec\drupol\phptree\Node\NodeObjectBehavior;
 
-class GraphSpec extends ObjectBehavior
+class GraphSpec extends NodeObjectBehavior
 {
     public function it_can_generate_a_graph()
     {
@@ -29,6 +29,10 @@ public function it_can_generate_a_graph()
         $this
             ->export($child1)
             ->shouldReturnAnInstanceOf(\Fhaculty\Graph\Graph::class);
+
+        $this
+            ->export($tree)
+            ->shouldHaveSameGraphImageFile($_SERVER['PWD'] . '/tests/fixtures/graphvizMvJSKP.png');
     }
 
     public function it_is_initializable()

spec/drupol/phptree/Node/NodeObjectBehavior.php

@@ -4,8 +4,10 @@
 
 namespace spec\drupol\phptree\Node;
 
+use drupol\phptree\Exporter\Graph;
 use drupol\phptree\Exporter\Text;
 use drupol\phptree\Node\NodeInterface;
+use Graphp\GraphViz\GraphViz;
 use PhpSpec\ObjectBehavior;
 
 /**
@@ -14,6 +16,8 @@
  * @method shouldHaveSameGraph(NodeInterface $node)
  * @method shouldHaveSameTextExport(string $export)
  * @method shouldNotHaveSameTextExport(string $export)
+ * @method shouldHaveSameGraphImage(NodeInterface $node)
+ * @method shouldHaveSameGraphImageFile(string $filepath)
  */
 abstract class NodeObjectBehavior extends ObjectBehavior
 {
@@ -45,6 +49,22 @@ public function getMatchers(): array
 
                 return $left !== $key;
             },
+            'haveSameGraphImage' => function ($subject, $key) {
+                $exporter = new Graph();
+
+                $left = $exporter->export($subject);
+                $right = $exporter->export($key);
+
+                $left = (new GraphViz())->setFormat('png')->createImageFile($left);
+                $right = (new GraphViz())->setFormat('png')->createImageFile($right);
+
+                return \file_get_contents($left) === \file_get_contents($right);
+            },
+            'haveSameGraphImageFile' => function ($subject, $key) {
+                $left = (new GraphViz())->setFormat('png')->createImageFile($subject);
+
+                return \file_get_contents($left) === \file_get_contents($key);
+            },
         ];
     }
 }

spec/drupol/phptree/Node/ValueNodeSpec.php

@@ -78,6 +78,19 @@ public function it_can_be_set_with_a_value()
             ->shouldReturn('root');
     }
 
+    public function it_can_draw_the_tree()
+    {
+        $this
+            ->beConstructedWith('root', 3);
+
+        foreach (\range(0, 30) as $number) {
+            $this->add(new ValueNode($number, 2));
+        }
+
+        $this
+            ->shouldHaveSameGraphImage($this->getWrappedObject());
+    }
+
     public function it_can_have_children()
     {
         $this