public function testDirnameBuilding() { $root = new Root(); $root->addDirectory($d1 = new Directory('dir1')); $root->addDirectory($d2 = new Directory('dir2')); $d2->addDirectory($d3 = new Directory('dir3')); $this->assertEquals(null, $root->dirname()); $this->assertEquals('/', $d1->dirname()); $this->assertEquals('/', $d2->dirname()); $this->assertEquals('/dir2', $d3->dirname()); }