Add tests with 100% coverage for new Algorithm\Loop

Author: clue

tests/LoopTest.php

@@ -0,0 +1,57 @@
+<?php
+
+use Fhaculty\Graph\Algorithm\Loop as AlgorithmLoop;
+use Fhaculty\Graph\Graph;
+
+class LoopTest extends TestCase
+{
+    public function testGraphEmpty()
+    {
+        $graph = new Graph();
+
+        $alg = new AlgorithmLoop($graph);
+
+        $this->assertFalse($alg->hasLoop());
+    }
+
+    public function testGraphWithMixedCircuitIsNotConsideredLoop()
+    {
+        // 1 -> 2
+        // 2 -- 1
+        $graph = new Graph();
+        $v1 = $graph->createVertex(1);
+        $v2 = $graph->createVertex(2);
+        $v1->createEdgeTo($v2);
+        $v2->createEdge($v1);
+
+        $alg = new AlgorithmLoop($graph);
+
+        $this->assertFalse($alg->hasLoop());
+        $this->assertFalse($alg->hasLoopVertex($v1));
+        $this->assertFalse($alg->hasLoopVertex($v2));
+    }
+
+    public function testGraphUndirectedLoop()
+    {
+        // 1 -- 1
+        $graph = new Graph();
+        $graph->createVertex(1)->createEdge($v1 = $graph->getVertex(1));
+
+        $alg = new AlgorithmLoop($graph);
+
+        $this->assertTrue($alg->hasLoop());
+        $this->assertTrue($alg->hasLoopVertex($v1));
+    }
+
+    public function testGraphDirectedLoop()
+    {
+        // 1 -> 1
+        $graph = new Graph();
+        $graph->createVertex(1)->createEdgeTo($v1 = $graph->getVertex(1));
+
+        $alg = new AlgorithmLoop($graph);
+
+        $this->assertTrue($alg->hasLoop());
+        $this->assertTrue($alg->hasLoopVertex($v1));
+    }
+}