class TestSuiteIterator

final class TestSuiteIterator implements RecursiveIterator {
    private int $position = 0;
    
    /**
     * @psalm-var list<Test>
     */
    private readonly array $tests;
    public function __construct(TestSuite $testSuite) {
        $this->tests = $testSuite->tests();
    }
    public function rewind() : void {
        $this->position = 0;
    }
    public function valid() : bool {
        return $this->position < count($this->tests);
    }
    public function key() : int {
        return $this->position;
    }
    public function current() : Test {
        return $this->tests[$this->position];
    }
    public function next() : void {
        $this->position++;
    }
    
    /**
     * @throws NoChildTestSuiteException
     */
    public function getChildren() : self {
        if (!$this->hasChildren()) {
            throw new NoChildTestSuiteException('The current item is not a TestSuite instance and therefore does not have any children.');
        }
        $current = $this->current();
        assert($current instanceof TestSuite);
        return new self($current);
    }
    public function hasChildren() : bool {
        return $this->valid() && $this->current() instanceof TestSuite;
    }

}