/**
* Tests whether the declaration of dependencies directly on the nodes works correctly
* and the dependencies are detected by the graph.
*
* @test
*/
public function testDeclarationOnNodes()
{
$graph = new DependencyGraph();
$nodeA = new DependencyNode('A');
$nodeB = new DependencyNode('B');
$nodeC = new DependencyNode('C');
$nodeD = new DependencyNode('D');
$nodeE = new DependencyNode('E');
$nodeA->dependsOn($nodeB);
$nodeA->dependsOn($nodeD);
$nodeB->dependsOn($nodeC);
$nodeB->dependsOn($nodeE);
$nodeC->dependsOn($nodeD);
$nodeC->dependsOn($nodeE);
$graph->addNode($nodeA);
$dependencies = $graph->getDependencies();
$this->assertEquals(array($nodeB, $nodeD), $dependencies[$nodeA]->getArrayCopy());
$this->assertEquals(array($nodeC, $nodeE), $dependencies[$nodeB]->getArrayCopy());
$this->assertEquals(array($nodeD, $nodeE), $dependencies[$nodeC]->getArrayCopy());
$this->assertEquals(array(), $dependencies[$nodeD]->getArrayCopy());
$this->assertEquals(array(), $dependencies[$nodeE]->getArrayCopy());
}
/**
* Brings the table into an order which respects dependencies between them.
*
* @param Table[] $tables
*
* @return Table[]
*/
public function sortTablesByDependencies(array $tables)
{
$nodes = array();
$dependencyGraph = new DependencyGraph();
// create nodes for each table
foreach ($tables as $table) {
$node = new DependencyNode($table, $table->getName());
$nodes[$table->getName()] = $node;
$dependencyGraph->addNode($node);
}
foreach ($tables as $table) {
foreach ($table->getForeignKeys() as $foreignKey) {
// TODO foreign keys pointing to own table not supported yet
if ($foreignKey->getForeignTableName() == $table->getName()) {
continue;
}
$dependencyGraph->addDependency($nodes[$table->getName()], $nodes[$foreignKey->getForeignTableName()]);
}
}
// TODO why the filter?
return array_filter($dependencyGraph->resolve());
}
