public function testComposite() { $expect = "/root\n/root/usr\n/root/usr/B\n/root/A\n"; $rootDir = new Directory("root"); $usrDir = new Directory("usr"); $fileA = new File("A"); $rootDir->add($usrDir); $rootDir->add($fileA); $fileB = new File("B"); $usrDir->add($fileB); $result = $rootDir->show(""); $this->assertEquals($result, $expect); }