PHPLIB-1167: Fix CachingIterator::count() on empty Cursor (#1118)

Fix error: "Cannot advance a completed or failed cursor."

src/Model/CachingIterator.php

@@ -110,8 +110,6 @@ public function next(): void
  $this->iterator->next();
 
  $this->storeCurrentItem();
-
- $this->iteratorExhausted = ! $this->iterator->valid();
  }
 
  next($this->items);
@@ -152,6 +150,8 @@ private function exhaustIterator(): void
  private function storeCurrentItem(): void
  {
  if (! $this->iterator->valid()) {
+ $this->iteratorExhausted = true;
+
  return;
  }
 

tests/Model/CachingIteratorFunctionalTest.php

@@ -0,0 +1,49 @@
+<?php
+
+namespace MongoDB\Tests\Model;
+
+use MongoDB\Model\CachingIterator;
+use MongoDB\Tests\FunctionalTestCase;
+
+class CachingIteratorFunctionalTest extends FunctionalTestCase
+{
+ /** @see https://jira.mongodb.org/browse/PHPLIB-1167 */
+ public function testEmptyCursor(): void
+ {
+ $collection = $this->dropCollection($this->getDatabaseName(), $this->getCollectionName());
+ $cursor = $collection->find();
+ $iterator = new CachingIterator($cursor);
+
+ $this->assertSame(0, $iterator->count());
+ $iterator->rewind();
+ $this->assertFalse($iterator->valid());
+ $this->assertFalse($iterator->current());
+ $this->assertNull($iterator->key());
+ }
+
+ public function testCursor(): void
+ {
+ $collection = $this->dropCollection($this->getDatabaseName(), $this->getCollectionName());
+ $collection->insertOne(['_id' => 1]);
+ $collection->insertOne(['_id' => 2]);
+ $cursor = $collection->find();
+ $iterator = new CachingIterator($cursor);
+
+ $this->assertSame(2, $iterator->count());
+
+ $iterator->rewind();
+ $this->assertTrue($iterator->valid());
+ $this->assertNotNull($iterator->current());
+ $this->assertSame(0, $iterator->key());
+
+ $iterator->next();
+ $this->assertTrue($iterator->valid());
+ $this->assertNotNull($iterator->current());
+ $this->assertSame(1, $iterator->key());
+
+ $iterator->next();
+ $this->assertFalse($iterator->valid());
+ $this->assertFalse($iterator->current());
+ $this->assertNull($iterator->key());
+ }
+}