diff --git a/core/tests/Drupal/Tests/Core/Entity/ChunkedIteratorTest.php b/core/tests/Drupal/Tests/Core/Entity/ChunkedIteratorTest.php
new file mode 100644
index 0000000..136867a
--- /dev/null
+++ b/core/tests/Drupal/Tests/Core/Entity/ChunkedIteratorTest.php
@@ -0,0 +1,185 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Tests\Core\Entity\ChunkedIteratorTest.
+ */
+
+namespace Drupal\Tests\Core\Entity;
+
+use Drupal\Core\Entity\ChunkedIterator;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * @group Entity
+ * @coversDefaultClass \Drupal\Core\Entity\ChunkedIterator
+ */
+class ChunkedIteratorTest extends UnitTestCase {
+
+  /**
+   * The entity storage.
+   *
+   * @var \Drupal\Core\Entity\EntityStorageInterface|\Prophecy\Prophecy\ObjectProphecy
+   */
+  protected $entityStorage;
+
+  /**
+   * The entity storage.
+   *
+   * @var \Drupal\Core\Entity\EntityInterface|\Prophecy\Prophecy\ObjectProphecy
+   */
+  protected $entity;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setUp() {
+    $this->entityStorage = $this->prophesize('Drupal\Core\Entity\EntityStorageInterface');
+    $this->entity = $this->prophesize('Drupal\Core\Entity\EntityInterface');
+  }
+
+  /**
+   * @covers ::count
+   */
+  public function testCountWithNoItems() {
+    $this->entityStorage->loadMultiple()->shouldNotBeCalled();
+    $iterator = new ChunkedIterator($this->entityStorage->reveal(), []);
+    $this->assertSame(0, $iterator->count());
+  }
+
+  /**
+   * @covers ::getIterator
+   * @covers ::loadEntities
+   */
+  public function testIterationWithNoItems() {
+    $this->entityStorage->resetCache()->shouldNotBeCalled();
+    $this->entityStorage->loadMultiple()->shouldNotBeCalled();
+
+    $iterator = new ChunkedIterator($this->entityStorage->reveal(), []);
+
+    foreach ($iterator as $entity) {
+
+    }
+  }
+
+  /**
+   * @covers ::getIterator
+   * @covers ::loadEntities
+   */
+  public function testIteratorWithNoValidItems() {
+    $this->entityStorage->resetCache()->shouldBeCalled();
+    $this->entityStorage->loadMultiple([1,2,3])
+      ->willReturn([])
+      ->shouldBeCalled();
+
+    $iterator = new ChunkedIterator($this->entityStorage->reveal(), [1,2,3]);
+
+    foreach ($iterator as $entity) {
+
+    }
+  }
+
+  /**
+   * @covers ::getIterator
+   * @covers ::loadEntities
+   */
+  public function testIteratorWithOneChunkValidItems() {
+    $return = [
+      1 => $this->entity->reveal(),
+      2 => $this->entity->reveal(),
+      3 => $this->entity->reveal(),
+    ];
+
+    $this->entityStorage->resetCache()->shouldBeCalled();
+    $this->entityStorage->loadMultiple([1,2,3])
+      ->willReturn($return)
+      ->shouldBeCalled();
+
+    $iterator = new ChunkedIterator($this->entityStorage->reveal(), [1,2,3]);
+
+    $this->assertSame($return, iterator_to_array($iterator));
+  }
+
+  /**
+   * @covers ::getIterator
+   * @covers ::loadEntities
+   */
+  public function testIteratorWithOneChunkInvalidItems() {
+    $return = [
+      2 => $this->entity->reveal(),
+      3 => $this->entity->reveal(),
+    ];
+
+    $this->entityStorage->resetCache()->shouldBeCalled();
+    $this->entityStorage->loadMultiple([1,2,3])
+      ->willReturn($return)
+      ->shouldBeCalled();
+
+    $iterator = new ChunkedIterator($this->entityStorage->reveal(), [1,2,3]);
+
+    $this->assertSame($return, iterator_to_array($iterator));
+  }
+
+  /**
+   * @covers ::getIterator
+   * @covers ::loadEntities
+   */
+  public function testIteratorWithMultipleChunkValidItems() {
+    $return_1 = [
+      1 => $this->entity->reveal(),
+      2 => $this->entity->reveal(),
+      3 => $this->entity->reveal(),
+    ];
+
+    $return_2 = [
+      4 => $this->entity->reveal(),
+      5 => $this->entity->reveal(),
+      6 => $this->entity->reveal(),
+    ];
+
+    $this->entityStorage->resetCache()->shouldBeCalled();
+    $this->entityStorage->loadMultiple([1, 2, 3])
+      ->willReturn($return_1)
+      ->shouldBeCalled();
+    $this->entityStorage->loadMultiple([4, 5, 6])
+      ->willReturn($return_2)
+      ->shouldBeCalled();
+
+    // Create a new iterator but set the cache limit to 3. Two chunks should be
+    // loaded.
+    $iterator = new ChunkedIterator($this->entityStorage->reveal(), [1, 2, 3, 4, 5, 6], 3);
+
+    $this->assertSame($return_1 + $return_2, iterator_to_array($iterator));
+  }
+
+  /**
+   * @covers ::getIterator
+   * @covers ::loadEntities
+   */
+  public function testIteratorWithMultipleChunkInvalidItems() {
+    $return_1 = [
+      2 => $this->entity->reveal(),
+      3 => $this->entity->reveal(),
+    ];
+
+    $return_2 = [
+      5 => $this->entity->reveal(),
+      6 => $this->entity->reveal(),
+    ];
+
+    $this->entityStorage->resetCache()->shouldBeCalled();
+    $this->entityStorage->loadMultiple([1, 2, 3])
+      ->willReturn($return_1)
+      ->shouldBeCalled();
+    $this->entityStorage->loadMultiple([4, 5, 6])
+      ->willReturn($return_2)
+      ->shouldBeCalled();
+
+    // Create a new iterator but set the cache limit to 3. Two chunks should be
+    // loaded.
+    $iterator = new ChunkedIterator($this->entityStorage->reveal(), [1, 2, 3, 4, 5, 6], 3);
+
+    $this->assertSame($return_1 + $return_2, iterator_to_array($iterator));
+  }
+
+}