Add tests for connected components (100% coverage)

Author: Christian Lück

tests/ConnectedComponentsTest.php

@@ -0,0 +1,97 @@
+<?php
+
+use Fhaculty\Graph\Algorithm\ConnectedComponents as AlgorithmConnected;
+use Fhaculty\Graph\Graph;
+
+class ConnectedComponentsTest extends TestCase
+{
+    public function testNullGraph()
+    {
+        $graph = new Graph();
+
+        $alg = new AlgorithmConnected($graph);
+
+        $this->assertEquals(0, $alg->getNumberOfComponents());
+        $this->assertFalse($alg->isSingle());
+        $this->assertCount(0, $alg->createGraphsComponents());
+    }
+
+    public function testGraphSingleTrivial()
+    {
+        $graph = new Graph();
+        $graph->createVertex(1);
+
+        $alg = new AlgorithmConnected($graph);
+
+        $this->assertEquals(1, $alg->getNumberOfComponents());
+        $this->assertTrue($alg->isSingle());
+
+        $graphs = $alg->createGraphsComponents();
+
+        $this->assertCount(1, $graphs);
+        $this->assertGraphEquals($graph, reset($graphs));
+    }
+
+    public function testGraphEdgeDirections()
+    {
+        // 1 -- 2 -> 3 <- 4
+        $graph = new Graph();
+        $graph->createVertex(1)->createEdge($graph->createVertex(2));
+        $graph->getVertex(2)->createEdgeTo($graph->createVertex(3));
+        $graph->createVertex(4)->createEdgeTo($graph->getVertex(3));
+
+        $alg = new AlgorithmConnected($graph);
+
+        $this->assertEquals(1, $alg->getNumberOfComponents());
+        $this->assertTrue($alg->isSingle());
+
+        $graphs = $alg->createGraphsComponents();
+
+        $this->assertCount(1, $graphs);
+        $this->assertGraphEquals($graph, reset($graphs));
+        $this->assertGraphEquals($graph, $alg->createGraphComponentVertex($graph->getVertex(1)));
+    }
+
+    public function testComponents()
+    {
+        // 1 -- 2, 3 -> 4, 5
+        $graph = new Graph();
+        $v1 = $graph->createVertex(1);
+        $v2 = $graph->createVertex(2);
+        $v3 = $graph->createVertex(3);
+        $v4 = $graph->createVertex(4);
+        $v5 = $graph->createVertex(5);
+        $e1 = $v1->createEdge($v2);
+        $e2 = $v3->createEdgeTo($v4);
+
+        $alg = new AlgorithmConnected($graph);
+
+        $this->assertEquals(3, $alg->getNumberOfComponents());
+        $this->assertFalse($alg->isSingle());
+
+        $graphs = $alg->createGraphsComponents();
+        $this->assertCount(3, $graphs);
+
+        $ge = new Graph();
+        $ge->createVertex(1)->createEdge($ge->createVertex(2));
+        $this->assertGraphEquals($ge, $alg->createGraphComponentVertex($v2));
+
+        $ge = new Graph();
+        $ge->createVertex(5);
+        $this->assertEquals($ge, $alg->createGraphComponentVertex($v5));
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testInvalidVertexPassedToAlgorithm()
+    {
+        $graph = new Graph();
+
+        $graph2 = new Graph();
+        $v2 = $graph2->createVertex(12);
+
+        $alg = new AlgorithmConnected($graph);
+        $alg->createGraphComponentVertex($v2);
+    }
+}