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Add proper unit tests for minimum spanning tree (~95% coverage)
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3 files changed

+193
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‎tests/MinimumSpanningTree/BaseMstTest.php

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<?php
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use Fhaculty\Graph\Graph;
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use Fhaculty\Graph\Vertex;
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use Fhaculty\Graph\Loader\CompleteGraph as LoaderCompleteGraph;
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use Fhaculty\Graph\Algorithm\MinimumSpanningTree\Base as MstBase;
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abstract class BaseMstTest extends TestCase
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{
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/**
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* @param Vertex $vertex
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* @return MstBase
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*/
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abstract protected function createAlg(Vertex $vertex);
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public function testIsolatedVertex()
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{
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$graph = new Graph();
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$v1 = $graph->createVertex(1);
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$alg = $this->createAlg($v1);
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$this->assertCount(0, $alg->getEdges());
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$this->assertEquals(0, $alg->getWeight());
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$graphMst = $alg->createGraph();
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$this->assertGraphEquals($graph, $graphMst);
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}
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public function testSingleEdge()
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{
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// 1 --[3]-- 2
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$graph = new Graph();
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$v1 = $graph->createVertex(1);
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$v2 = $graph->createVertex(2);
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$v1->createEdge($v2)->setWeight(3);
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$alg = $this->createAlg($v1);
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$this->assertCount(1, $alg->getEdges());
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$this->assertEquals(3, $alg->getWeight());
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$this->assertGraphEquals($graph, $alg->createGraph());
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}
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public function testSimpleGraph()
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{
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// 1 --[6]-- 2 --[9]-- 3 --[7]-- 4 --[8]-- 5
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$graph = new Graph();
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$v1 = $graph->createVertex(1);
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$v2 = $graph->createVertex(2);
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$v1->createEdge($v2)->setWeight(3);
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$alg = $this->createAlg($v1);
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$graphMst = $alg->createGraph();
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$this->assertGraphEquals($graph, $graphMst);
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}
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public function testFindingCheapestEdge()
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{
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// /--[4]--\
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// / \
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// 1 ---[3]--- 2
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// \ /
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// \--[5]--/
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$graph = new Graph();
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$v1 = $graph->createVertex(1);
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$v2 = $graph->createVertex(2);
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$v1->createEdge($v2)->setWeight(4);
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$v1->createEdge($v2)->setWeight(3);
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$v1->createEdge($v2)->setWeight(5);
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$alg = $this->createAlg($v1);
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$edges = $alg->getEdges();
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$this->assertCount(1, $edges);
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$this->assertEquals(3, $edges->getEdgeFirst()->getWeight());
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$this->assertEquals(3, $alg->getWeight());
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}
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public function testFindingCheapestTree()
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{
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// 1 --[4]-- 2 --[5]-- 3
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// \ /
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// \-------[6]-----/
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$graph = new Graph();
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$v1 = $graph->createVertex(1);
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$v2 = $graph->createVertex(2);
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$v3 = $graph->createVertex(3);
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$v1->createEdge($v2)->setWeight(4);
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$v2->createEdge($v3)->setWeight(5);
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$v3->createEdge($v1)->setWeight(6);
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// 1 --[4]-- 2 -- [5] -- 3
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$graphExpected = new Graph();
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$ve1 = $graphExpected->createVertex(1);
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$ve2 = $graphExpected->createVertex(2);
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$ve3 = $graphExpected->createVertex(3);
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$ve1->createEdge($ve2)->setWeight(4);
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$ve2->createEdge($ve3)->setWeight(5);
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$alg = $this->createAlg($v1);
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$this->assertCount(2, $alg->getEdges());
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$this->assertEquals(9, $alg->getWeight());
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$this->assertGraphEquals($graphExpected, $alg->createGraph());
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}
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public function testMixedGraphDirectionIsIgnored()
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{
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// 1 --[6]-> 2 --[7]-- 3 --[8]-- 4 <-[9]-- 5
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$graph = new Graph();
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$v1 = $graph->createVertex(1);
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$v2 = $graph->createVertex(2);
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$v3 = $graph->createVertex(3);
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$v4 = $graph->createVertex(4);
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$v5 = $graph->createVertex(5);
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$v1->createEdgeTo($v2)->setWeight(6);
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$v2->createEdge($v3)->setWeight(7);
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$v4->createEdge($v3)->setWeight(8);
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$v5->createEdgeTo($v4)->setWeight(9);
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$alg = $this->createAlg($v1);
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$this->assertCount(4, $alg->getEdges());
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$this->assertEquals(30, $alg->getWeight());
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$this->assertGraphEquals($graph, $alg->createGraph());
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}
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/**
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* @expectedException UnexpectedValueException
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*/
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public function testMultipleComponentsFail()
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{
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// 1 --[1]-- 2, 3 --[1]-- 4
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$graph = new Graph();
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$v1 = $graph->createVertex(1);
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$v2 = $graph->createVertex(2);
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$v3 = $graph->createVertex(3);
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$v4 = $graph->createVertex(4);
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$v1->createEdge($v2)->setWeight(1);
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$v3->createEdge($v4)->setWeight(1);
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$alg = $this->createAlg($v1);
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$alg->getEdges();
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}
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/**
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* @expectedException UnexpectedValueException
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*/
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public function testMultipleIsolatedVerticesFormMultipleComponentsFail()
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{
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// 1, 2
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$graph = new Graph();
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$v1 = $graph->createVertex(1);
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$v2 = $graph->createVertex(2);
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$alg = $this->createAlg($v1);
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$alg->getEdges();
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}
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}

‎tests/MinimumSpanningTree/KruskalTest.php

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<?php
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use Fhaculty\Graph\Graph;
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use Fhaculty\Graph\Vertex;
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use Fhaculty\Graph\Algorithm\MinimumSpanningTree\Kruskal;
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class KruskalTest extends BaseMstTest
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{
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protected function createAlg(Vertex $vertex)
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{
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return new Kruskal($vertex->getGraph());
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}
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/**
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* @expectedException UnexpectedValueException
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*/
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public function testNullGraphIsNotConsideredToBeConnected()
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{
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$graph = new Graph();
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$alg = new Kruskal($graph);
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$alg->getEdges();
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}
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}

‎tests/MinimumSpanningTree/PrimTest.php

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<?php
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use Fhaculty\Graph\Algorithm\MinimumSpanningTree\Prim as AlgorithmMSTPrim;
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use Fhaculty\Graph\Loader\CompleteGraph as LoaderCompleteGraph;
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class PrimTest extends PHPUnit_Framework_TestCase
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{
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public function testKnownComplete()
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{
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$this->assertCount(4, $this->getResultForComplete(5));
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}
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use Fhaculty\Graph\Vertex;
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use Fhaculty\Graph\Algorithm\MinimumSpanningTree\Prim;
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protected function getResultForComplete($n)
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class PrimTest extends BaseMstTest
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{
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protected function createAlg(Vertex $vertex)
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{
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$loader = new LoaderCompleteGraph($n);
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$loader->setEnableDirectedEdges(false);
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$alg = new AlgorithmMSTPrim($loader->createGraph()->getVertex(1));
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return $alg->getEdges();
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return new Prim($vertex);
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}
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}

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