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<?php
namespace MongoDB\Tests\Model;
use MongoDB\Model\CachingIterator;
use MongoDB\Tests\TestCase;
use Exception;
class CachingIteratorTest extends TestCase
{
public function testTraversingGeneratorConsumesIt()
{
$iterator = $this->getTraversable([1, 2, 3]);
$this->assertSame([1, 2, 3], iterator_to_array($iterator));
$this->expectException(Exception::class);
$this->expectExceptionMessage('Cannot traverse an already closed generator');
iterator_to_array($iterator);
}
public function testConstructorRewinds()
{
$iterator = new CachingIterator($this->getTraversable([1, 2, 3]));
$this->assertTrue($iterator->valid());
$this->assertSame(0, $iterator->key());
$this->assertSame(1, $iterator->current());
}
public function testIteration()
{
$iterator = new CachingIterator($this->getTraversable([1, 2, 3]));
$expectedKey = 0;
$expectedItem = 1;
foreach ($iterator as $key => $item) {
$this->assertSame($expectedKey++, $key);
$this->assertSame($expectedItem++, $item);
}
$this->assertFalse($iterator->valid());
}
public function testIterationWithEmptySet()
{
$iterator = new CachingIterator($this->getTraversable([]));
$iterator->rewind();
$this->assertFalse($iterator->valid());
}
public function testPartialIterationDoesNotExhaust()
{
$traversable = $this->getTraversableThatThrows([1, 2, new Exception]);
$iterator = new CachingIterator($traversable);
$expectedKey = 0;
$expectedItem = 1;
foreach ($iterator as $key => $item) {
$this->assertSame($expectedKey++, $key);
$this->assertSame($expectedItem++, $item);
if ($key === 1) {
break;
}
}
$this->assertTrue($iterator->valid());
}
public function testRewindAfterPartialIteration()
{
$iterator = new CachingIterator($this->getTraversable([1, 2, 3]));
$iterator->rewind();
$this->assertTrue($iterator->valid());
$this->assertSame(0, $iterator->key());
$this->assertSame(1, $iterator->current());
$iterator->next();
$this->assertSame([1, 2, 3], iterator_to_array($iterator));
}
public function testCount()
{
$iterator = new CachingIterator($this->getTraversable([1, 2, 3]));
$this->assertCount(3, $iterator);
}
public function testCountAfterPartialIteration()
{
$iterator = new CachingIterator($this->getTraversable([1, 2, 3]));
$iterator->rewind();
$this->assertTrue($iterator->valid());
$this->assertSame(0, $iterator->key());
$this->assertSame(1, $iterator->current());
$iterator->next();
$this->assertCount(3, $iterator);
}
public function testCountWithEmptySet()
{
$iterator = new CachingIterator($this->getTraversable([]));
$this->assertCount(0, $iterator);
}
private function getTraversable($items)
{
foreach ($items as $item) {
yield $item;
}
}
private function getTraversableThatThrows($items)
{
foreach ($items as $item) {
if ($item instanceof Exception) {
throw $item;
} else {
yield $item;
}
}
}
}