GenericCacheBackendUnitTestBase.php

<?php

/**
 * @file
 * Definition of Drupal\system\Tests\Cache\GenericCacheBackendUnitTestBase.
 */
namespace Drupal\system\Tests\Cache;

use Drupal\Core\Cache\CacheBackendInterface;
use Drupal\simpletest\UnitTestBase;
use stdClass;

/**
 * Tests any cache backend.
 *
 * Full generic unit test suite for any cache backend. In order to use it for a
 * cache backend implementation, extend this class and override the
 * createBackendInstace() method to return an object.
 *
 * @see DatabaseBackendUnitTestCase
 *   For a full working implementation.
 */
abstract class GenericCacheBackendUnitTestBase extends UnitTestBase {

  /**
   * Array of objects implementing Drupal\Core\Cache\CacheBackendInterface.
   *
   * @var array
   */
  protected $cachebackends;

  /**
   * Cache bin to use for testing.
   *
   * @var string
   */
  protected $testBin;

  /**
   * Random value to use in tests.
   *
   * @var string
   */
  protected $defaultValue;

  /**
   * Gets the testing bin.
   *
   * Override this method if you want to work on a different bin than the
   * default one.
   *
   * @return string
   *   Bin name.
   */
  protected function getTestBin() {
    if (!isset($this->testBin)) {
      $this->testBin = 'page';
    }
    return $this->testBin;
  }

  /**
   * Creates a cache backend to test.
   *
   * Override this method to test a CacheBackend.
   *
   * @param string $bin
   *   Bin name to use for this backend instance.
   *
   * @return Drupal\Core\Cache\CacheBackendInterface
   *   Cache backend to test.
   */
  protected abstract function createCacheBackend($bin);

  /**
   * Allows specific implementation to change the environment before a test run.
   */
  public function setUpCacheBackend() {
  }

  /**
   * Allows alteration of environment after a test run but before tear down.
   *
   * Used before the real tear down because the tear down will change things
   * such as the database prefix.
   */
  public function tearDownCacheBackend() {
  }

  /**
   * Gets a backend to test; this will get a shared instance set in the object.
   *
   * @return Drupal\Core\Cache\CacheBackendInterface
   *   Cache backend to test.
   */
  final function getCacheBackend($bin = null) {
    if (!isset($bin)) {
      $bin = $this
        ->getTestBin();
    }
    if (!isset($this->cachebackends[$bin])) {
      $this->cachebackends[$bin] = $this
        ->createCacheBackend($bin);

      // Ensure the backend is empty.
      $this->cachebackends[$bin]
        ->deleteAll();
    }
    return $this->cachebackends[$bin];
  }
  public function setUp() {
    $this->cachebackends = array();
    $this->defaultValue = $this
      ->randomName(10);
    parent::setUp();
    $this
      ->setUpCacheBackend();
  }
  public function tearDown() {

    // Destruct the registered backend, each test will get a fresh instance,
    // properly emptying it here ensure that on persistant data backends they
    // will come up empty the next test.
    foreach ($this->cachebackends as $bin => $cachebackend) {
      $this->cachebackends[$bin]
        ->deleteAll();
    }
    unset($this->cachebackends);
    $this
      ->tearDownCacheBackend();
    parent::tearDown();
  }

  /**
   * Tests the get and set methods of Drupal\Core\Cache\CacheBackendInterface.
   */
  public function testSetGet() {
    $backend = $this
      ->getCacheBackend();
    $this
      ->assertIdentical(FALSE, $backend
      ->get('test1'), "Backend does not contain data for cache id test1.");
    $backend
      ->set('test1', 7);
    $cached = $backend
      ->get('test1');
    $this
      ->assert(is_object($cached), "Backend returned an object for cache id test1.");
    $this
      ->assertIdentical(7, $cached->data);
    $this
      ->assertTrue($cached->valid, 'Item is marked as valid.');
    $this
      ->assertEqual($cached->created, REQUEST_TIME, 'Created time is correct.');
    $this
      ->assertEqual($cached->expire, CacheBackendInterface::CACHE_PERMANENT, 'Expire time is correct.');
    $this
      ->assertIdentical(FALSE, $backend
      ->get('test2'), "Backend does not contain data for cache id test2.");
    $backend
      ->set('test2', array(
      'value' => 3,
    ), REQUEST_TIME + 3);
    $cached = $backend
      ->get('test2');
    $this
      ->assert(is_object($cached), "Backend returned an object for cache id test2.");
    $this
      ->assertIdentical(array(
      'value' => 3,
    ), $cached->data);
    $this
      ->assertTrue($cached->valid, 'Item is marked as valid.');
    $this
      ->assertEqual($cached->created, REQUEST_TIME, 'Created time is correct.');
    $this
      ->assertEqual($cached->expire, REQUEST_TIME + 3, 'Expire time is correct.');
    $backend
      ->set('test3', 'foobar', REQUEST_TIME - 3);
    $this
      ->assertFalse($backend
      ->get('test3'), 'Invalid item not returned.');
    $cached = $backend
      ->get('test3', TRUE);
    $this
      ->assert(is_object($cached), 'Backend returned an object for cache id test3.');
    $this
      ->assertFalse($cached->valid, 'Item is marked as valid.');
    $this
      ->assertEqual($cached->created, REQUEST_TIME, 'Created time is correct.');
    $this
      ->assertEqual($cached->expire, REQUEST_TIME - 3, 'Expire time is correct.');
  }

  /**
   * Tests Drupal\Core\Cache\CacheBackendInterface::delete().
   */
  public function testDelete() {
    $backend = $this
      ->getCacheBackend();
    $this
      ->assertIdentical(FALSE, $backend
      ->get('test1'), "Backend does not contain data for cache id test1.");
    $backend
      ->set('test1', 7);
    $this
      ->assert(is_object($backend
      ->get('test1')), "Backend returned an object for cache id test1.");
    $this
      ->assertIdentical(FALSE, $backend
      ->get('test2'), "Backend does not contain data for cache id test2.");
    $backend
      ->set('test2', 3);
    $this
      ->assert(is_object($backend
      ->get('test2')), "Backend returned an object for cache id %cid.");
    $backend
      ->delete('test1');
    $this
      ->assertIdentical(FALSE, $backend
      ->get('test1'), "Backend does not contain data for cache id test1 after deletion.");
    $cached = $backend
      ->get('test2');
    $this
      ->assert(is_object($backend
      ->get('test2')), "Backend still has an object for cache id test2.");
    $backend
      ->delete('test2');
    $this
      ->assertIdentical(FALSE, $backend
      ->get('test2'), "Backend does not contain data for cache id test2 after deletion.");
  }

  /**
   * Tests data type preservation.
   */
  public function testValueTypeIsKept() {
    $backend = $this
      ->getCacheBackend();
    $variables = array(
      'test1' => 1,
      'test2' => '0',
      'test3' => '',
      'test4' => 12.64,
      'test5' => FALSE,
      'test6' => array(
        1,
        2,
        3,
      ),
    );

    // Create cache entries.
    foreach ($variables as $cid => $data) {
      $backend
        ->set($cid, $data);
    }

    // Retrieve and test cache objects.
    foreach ($variables as $cid => $value) {
      $object = $backend
        ->get($cid);
      $this
        ->assert(is_object($object), sprintf("Backend returned an object for cache id %s.", $cid));
      $this
        ->assertIdentical($value, $object->data, sprintf("Data of cached id %s kept is identical in type and value", $cid));
    }
  }

  /**
   * Tests Drupal\Core\Cache\CacheBackendInterface::getMultiple().
   */
  public function testGetMultiple() {
    $backend = $this
      ->getCacheBackend();

    // Set numerous testing keys.
    $backend
      ->set('test1', 1);
    $backend
      ->set('test2', 3);
    $backend
      ->set('test3', 5);
    $backend
      ->set('test4', 7);
    $backend
      ->set('test5', 11);
    $backend
      ->set('test6', 13);
    $backend
      ->set('test7', 17);

    // Mismatch order for harder testing.
    $reference = array(
      'test3',
      'test7',
      'test21',
      // Cid does not exist.
      'test6',
      'test19',
      // Cid does not exist until added before second getMultiple().
      'test2',
    );
    $cids = $reference;
    $ret = $backend
      ->getMultiple($cids);

    // Test return - ensure it contains existing cache ids.
    $this
      ->assert(isset($ret['test2']), "Existing cache id test2 is set.");
    $this
      ->assert(isset($ret['test3']), "Existing cache id test3 is set.");
    $this
      ->assert(isset($ret['test6']), "Existing cache id test6 is set.");
    $this
      ->assert(isset($ret['test7']), "Existing cache id test7 is set.");

    // Test return - ensure that objects has expected properties.
    $this
      ->assertTrue($ret['test2']->valid, 'Item is marked as valid.');
    $this
      ->assertEqual($ret['test2']->created, REQUEST_TIME, 'Created time is correct.');
    $this
      ->assertEqual($ret['test2']->expire, CacheBackendInterface::CACHE_PERMANENT, 'Expire time is correct.');

    // Test return - ensure it does not contain nonexistent cache ids.
    $this
      ->assertFalse(isset($ret['test19']), "Nonexistent cache id test19 is not set.");
    $this
      ->assertFalse(isset($ret['test21']), "Nonexistent cache id test21 is not set.");

    // Test values.
    $this
      ->assertIdentical($ret['test2']->data, 3, "Existing cache id test2 has the correct value.");
    $this
      ->assertIdentical($ret['test3']->data, 5, "Existing cache id test3 has the correct value.");
    $this
      ->assertIdentical($ret['test6']->data, 13, "Existing cache id test6 has the correct value.");
    $this
      ->assertIdentical($ret['test7']->data, 17, "Existing cache id test7 has the correct value.");

    // Test $cids array - ensure it contains cache id's that do not exist.
    $this
      ->assert(in_array('test19', $cids), "Nonexistent cache id test19 is in cids array.");
    $this
      ->assert(in_array('test21', $cids), "Nonexistent cache id test21 is in cids array.");

    // Test $cids array - ensure it does not contain cache id's that exist.
    $this
      ->assertFalse(in_array('test2', $cids), "Existing cache id test2 is not in cids array.");
    $this
      ->assertFalse(in_array('test3', $cids), "Existing cache id test3 is not in cids array.");
    $this
      ->assertFalse(in_array('test6', $cids), "Existing cache id test6 is not in cids array.");
    $this
      ->assertFalse(in_array('test7', $cids), "Existing cache id test7 is not in cids array.");

    // Test a second time after deleting and setting new keys which ensures that
    // if the backend uses statics it does not cause unexpected results.
    $backend
      ->delete('test3');
    $backend
      ->delete('test6');
    $backend
      ->set('test19', 57);
    $cids = $reference;
    $ret = $backend
      ->getMultiple($cids);

    // Test return - ensure it contains existing cache ids.
    $this
      ->assert(isset($ret['test2']), "Existing cache id test2 is set");
    $this
      ->assert(isset($ret['test7']), "Existing cache id test7 is set");
    $this
      ->assert(isset($ret['test19']), "Added cache id test19 is set");

    // Test return - ensure it does not contain nonexistent cache ids.
    $this
      ->assertFalse(isset($ret['test3']), "Deleted cache id test3 is not set");
    $this
      ->assertFalse(isset($ret['test6']), "Deleted cache id test6 is not set");
    $this
      ->assertFalse(isset($ret['test21']), "Nonexistent cache id test21 is not set");

    // Test values.
    $this
      ->assertIdentical($ret['test2']->data, 3, "Existing cache id test2 has the correct value.");
    $this
      ->assertIdentical($ret['test7']->data, 17, "Existing cache id test7 has the correct value.");
    $this
      ->assertIdentical($ret['test19']->data, 57, "Added cache id test19 has the correct value.");

    // Test $cids array - ensure it contains cache id's that do not exist.
    $this
      ->assert(in_array('test3', $cids), "Deleted cache id test3 is in cids array.");
    $this
      ->assert(in_array('test6', $cids), "Deleted cache id test6 is in cids array.");
    $this
      ->assert(in_array('test21', $cids), "Nonexistent cache id test21 is in cids array.");

    // Test $cids array - ensure it does not contain cache id's that exist.
    $this
      ->assertFalse(in_array('test2', $cids), "Existing cache id test2 is not in cids array.");
    $this
      ->assertFalse(in_array('test7', $cids), "Existing cache id test7 is not in cids array.");
    $this
      ->assertFalse(in_array('test19', $cids), "Added cache id test19 is not in cids array.");
  }

  /**
   * Tests Drupal\Core\Cache\CacheBackendInterface::isEmpty().
   */
  public function testIsEmpty() {
    $backend = $this
      ->getCacheBackend();
    $this
      ->assertTrue($backend
      ->isEmpty(), "Backend is empty.");
    $backend
      ->set('pony', "Shetland");
    $this
      ->assertFalse($backend
      ->isEmpty(), "Backend is not empty.");
    $backend
      ->delete('pony');
    $this
      ->assertTrue($backend
      ->isEmpty(), "Backend is empty.");
  }

  /**
   * Test Drupal\Core\Cache\CacheBackendInterface::delete() and
   * Drupal\Core\Cache\CacheBackendInterface::deleteMultiple().
   */
  public function testDeleteMultiple() {
    $backend = $this
      ->getCacheBackend();

    // Set numerous testing keys.
    $backend
      ->set('test1', 1);
    $backend
      ->set('test2', 3);
    $backend
      ->set('test3', 5);
    $backend
      ->set('test4', 7);
    $backend
      ->set('test5', 11);
    $backend
      ->set('test6', 13);
    $backend
      ->set('test7', 17);
    $backend
      ->delete('test1');
    $backend
      ->delete('test23');

    // Nonexistent key should not cause an error.
    $backend
      ->deleteMultiple(array(
      'test3',
      'test5',
      'test7',
      'test19',
      // Nonexistent key should not cause an error.
      'test21',
    ));

    // Test if expected keys have been deleted.
    $this
      ->assertIdentical(FALSE, $backend
      ->get('test1'), "Cache id test1 deleted.");
    $this
      ->assertIdentical(FALSE, $backend
      ->get('test3'), "Cache id test3 deleted.");
    $this
      ->assertIdentical(FALSE, $backend
      ->get('test5'), "Cache id test5 deleted.");
    $this
      ->assertIdentical(FALSE, $backend
      ->get('test7'), "Cache id test7 deleted.");

    // Test if expected keys exist.
    $this
      ->assertNotIdentical(FALSE, $backend
      ->get('test2'), "Cache id test2 exists.");
    $this
      ->assertNotIdentical(FALSE, $backend
      ->get('test4'), "Cache id test4 exists.");
    $this
      ->assertNotIdentical(FALSE, $backend
      ->get('test6'), "Cache id test6 exists.");

    // Test if that expected keys do not exist.
    $this
      ->assertIdentical(FALSE, $backend
      ->get('test19'), "Cache id test19 does not exist.");
    $this
      ->assertIdentical(FALSE, $backend
      ->get('test21'), "Cache id test21 does not exist.");
  }

  /**
   * Tests Drupal\Core\Cache\CacheBackendInterface::deleteTags().
   */
  function testDeleteTags() {
    $backend = $this
      ->getCacheBackend();

    // Create two cache entries with the same tag and tag value.
    $backend
      ->set('test_cid_invalidate1', $this->defaultValue, CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag' => 2,
    ));
    $backend
      ->set('test_cid_invalidate2', $this->defaultValue, CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag' => 2,
    ));
    $this
      ->assertTrue($backend
      ->get('test_cid_invalidate1') && $backend
      ->get('test_cid_invalidate2'), 'Two cache items were created.');

    // Delete test_tag of value 1. This should delete both entries.
    $backend
      ->deleteTags(array(
      'test_tag' => 2,
    ));
    $this
      ->assertFalse($backend
      ->get('test_cid_invalidate1') || $backend
      ->get('test_cid_invalidate2'), 'Two cache items invalidated after deleting a cache tag.');
    $this
      ->assertFalse($backend
      ->get('test_cid_invalidate1', TRUE) || $backend
      ->get('test_cid_invalidate2', TRUE), 'Two cache items deleted after deleting a cache tag.');

    // Create two cache entries with the same tag and an array tag value.
    $backend
      ->set('test_cid_invalidate1', $this->defaultValue, CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag' => array(
        1,
      ),
    ));
    $backend
      ->set('test_cid_invalidate2', $this->defaultValue, CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag' => array(
        1,
      ),
    ));
    $this
      ->assertTrue($backend
      ->get('test_cid_invalidate1') && $backend
      ->get('test_cid_invalidate2'), 'Two cache items were created.');

    // Delete test_tag of value 1. This should delete both entries.
    $backend
      ->deleteTags(array(
      'test_tag' => array(
        1,
      ),
    ));
    $this
      ->assertFalse($backend
      ->get('test_cid_invalidate1') || $backend
      ->get('test_cid_invalidate2'), 'Two cache items invalidated after deleted a cache tag.');
    $this
      ->assertFalse($backend
      ->get('test_cid_invalidate1', TRUE) || $backend
      ->get('test_cid_invalidate2', TRUE), 'Two cache items deleted after deleting a cache tag.');

    // Create three cache entries with a mix of tags and tag values.
    $backend
      ->set('test_cid_invalidate1', $this->defaultValue, CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag' => array(
        1,
      ),
    ));
    $backend
      ->set('test_cid_invalidate2', $this->defaultValue, CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag' => array(
        2,
      ),
    ));
    $backend
      ->set('test_cid_invalidate3', $this->defaultValue, CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag_foo' => array(
        3,
      ),
    ));
    $this
      ->assertTrue($backend
      ->get('test_cid_invalidate1') && $backend
      ->get('test_cid_invalidate2') && $backend
      ->get('test_cid_invalidate3'), 'Three cached items were created.');
    $backend
      ->deleteTags(array(
      'test_tag_foo' => array(
        3,
      ),
    ));
    $this
      ->assertTrue($backend
      ->get('test_cid_invalidate1') && $backend
      ->get('test_cid_invalidate2'), 'Cached items not matching the tag were not deleted.');
    $this
      ->assertFalse($backend
      ->get('test_cid_invalidated3', TRUE), 'Cache item matching the tag was deleted.');

    // Create cache entry in multiple bins. Two cache entries
    // (test_cid_invalidate1 and test_cid_invalidate2) still exist from previous
    // tests.
    $tags = array(
      'test_tag' => array(
        1,
        2,
        3,
      ),
    );
    $bins = array(
      'path',
      'bootstrap',
      'page',
    );
    foreach ($bins as $bin) {
      $this
        ->getCacheBackend($bin)
        ->set('test', $this->defaultValue, CacheBackendInterface::CACHE_PERMANENT, $tags);
      $this
        ->assertTrue($this
        ->getCacheBackend($bin)
        ->get('test'), 'Cache item was set in bin.');
    }

    // Delete tag in mulitple bins.
    foreach ($bins as $bin) {
      $this
        ->getCacheBackend($bin)
        ->deleteTags(array(
        'test_tag' => array(
          2,
        ),
      ));
    }

    // Test that cache entry has been deleted in multple bins.
    foreach ($bins as $bin) {
      $this
        ->assertFalse($this
        ->getCacheBackend($bin)
        ->get('test', TRUE), 'Tag deletion affected item in bin.');
    }

    // Test that the cache entry with a matching tag has been invalidated.
    $this
      ->assertFalse($this
      ->getCacheBackend($bin)
      ->get('test_cid_invalidate2', TRUE), 'Cache items matching tag were deleted.');

    // Test that the cache entry with without a matching tag still exists.
    $this
      ->assertTrue($this
      ->getCacheBackend($bin)
      ->get('test_cid_invalidate1'), 'Cache items not matching tag were not invalidated.');
  }

  /**
   * Test Drupal\Core\Cache\CacheBackendInterface::deleteAll().
   */
  public function testDeleteAll() {
    $backend = $this
      ->getCacheBackend();

    // Set both expiring and permanent keys.
    $backend
      ->set('test1', 1, CacheBackendInterface::CACHE_PERMANENT);
    $backend
      ->set('test2', 3, time() + 1000);
    $backend
      ->deleteAll();
    $this
      ->assertTrue($backend
      ->isEmpty(), "Backend is empty after deleteAll().");
    $this
      ->assertFalse($backend
      ->get('test1'), 'First key has been deleted.');
    $this
      ->assertFalse($backend
      ->get('test2'), 'Second key has been deleted.');
  }

  /**
   * Test Drupal\Core\Cache\CacheBackendInterface::invalidate() and
   * Drupal\Core\Cache\CacheBackendInterface::invalidateMultiple().
   */
  function testInvalidate() {
    $backend = $this
      ->getCacheBackend();
    $backend
      ->set('test1', 1);
    $backend
      ->set('test2', 2);
    $backend
      ->set('test3', 2);
    $backend
      ->set('test4', 2);
    $reference = array(
      'test1',
      'test2',
      'test3',
      'test4',
    );
    $cids = $reference;
    $ret = $backend
      ->getMultiple($cids);
    $this
      ->assertEqual(count($ret), 4, 'Four items returned.');
    $backend
      ->invalidate('test1');
    $backend
      ->invalidateMultiple(array(
      'test2',
      'test3',
    ));
    $cids = $reference;
    $ret = $backend
      ->getMultiple($cids);
    $this
      ->assertEqual(count($ret), 1, 'Only one item element returned.');
    $cids = $reference;
    $ret = $backend
      ->getMultiple($cids, TRUE);
    $this
      ->assertEqual(count($ret), 4, 'Four items returned.');
  }

  /**
   * Tests Drupal\Core\Cache\CacheBackendInterface::invalidateTags().
   */
  function testInvalidateTags() {
    $backend = $this
      ->getCacheBackend();

    // Create two cache entries with the same tag and tag value.
    $backend
      ->set('test_cid_invalidate1', $this->defaultValue, CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag' => 2,
    ));
    $backend
      ->set('test_cid_invalidate2', $this->defaultValue, CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag' => 2,
    ));
    $this
      ->assertTrue($backend
      ->get('test_cid_invalidate1') && $backend
      ->get('test_cid_invalidate2'), 'Two cache items were created.');

    // Invalidate test_tag of value 1. This should invalidate both entries.
    $backend
      ->invalidateTags(array(
      'test_tag' => 2,
    ));
    $this
      ->assertFalse($backend
      ->get('test_cid_invalidate1') || $backend
      ->get('test_cid_invalidate2'), 'Two cache items invalidated after invalidating a cache tag.');
    $this
      ->assertTrue($backend
      ->get('test_cid_invalidate1', TRUE) && $backend
      ->get('test_cid_invalidate2', TRUE), 'Cache items not deleted after invalidating a cache tag.');

    // Create two cache entries with the same tag and an array tag value.
    $backend
      ->set('test_cid_invalidate1', $this->defaultValue, CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag' => array(
        1,
      ),
    ));
    $backend
      ->set('test_cid_invalidate2', $this->defaultValue, CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag' => array(
        1,
      ),
    ));
    $this
      ->assertTrue($backend
      ->get('test_cid_invalidate1') && $backend
      ->get('test_cid_invalidate2'), 'Two cache items were created.');

    // Invalidate test_tag of value 1. This should invalidate both entries.
    $backend
      ->invalidateTags(array(
      'test_tag' => array(
        1,
      ),
    ));
    $this
      ->assertFalse($backend
      ->get('test_cid_invalidate1') || $backend
      ->get('test_cid_invalidate2'), 'Two caches removed after invalidating a cache tag.');
    $this
      ->assertTrue($backend
      ->get('test_cid_invalidate1', TRUE) && $backend
      ->get('test_cid_invalidate2', TRUE), 'Cache items not deleted after invalidating a cache tag.');

    // Create three cache entries with a mix of tags and tag values.
    $backend
      ->set('test_cid_invalidate1', $this->defaultValue, CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag' => array(
        1,
      ),
    ));
    $backend
      ->set('test_cid_invalidate2', $this->defaultValue, CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag' => array(
        2,
      ),
    ));
    $backend
      ->set('test_cid_invalidate3', $this->defaultValue, CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag_foo' => array(
        3,
      ),
    ));
    $this
      ->assertTrue($backend
      ->get('test_cid_invalidate1') && $backend
      ->get('test_cid_invalidate2') && $backend
      ->get('test_cid_invalidate3'), 'Three cached items were created.');
    $backend
      ->invalidateTags(array(
      'test_tag_foo' => array(
        3,
      ),
    ));
    $this
      ->assertTrue($backend
      ->get('test_cid_invalidate1') && $backend
      ->get('test_cid_invalidate2'), 'Cache items not matching the tag were not invalidated.');
    $this
      ->assertFalse($backend
      ->get('test_cid_invalidated3'), 'Cached item matching the tag was removed.');

    // Create cache entry in multiple bins. Two cache entries
    // (test_cid_invalidate1 and test_cid_invalidate2) still exist from previous
    // tests.
    $tags = array(
      'test_tag' => array(
        1,
        2,
        3,
      ),
    );
    $bins = array(
      'path',
      'bootstrap',
      'page',
    );
    foreach ($bins as $bin) {
      $this
        ->getCacheBackend($bin)
        ->set('test', $this->defaultValue, CacheBackendInterface::CACHE_PERMANENT, $tags);
      $this
        ->assertTrue($this
        ->getCacheBackend($bin)
        ->get('test'), 'Cache item was set in bin.');
    }

    // Invalidate tag in mulitple bins.
    foreach ($bins as $bin) {
      $this
        ->getCacheBackend($bin)
        ->invalidateTags(array(
        'test_tag' => array(
          2,
        ),
      ));
    }

    // Test that cache entry has been invalidated in multple bins.
    foreach ($bins as $bin) {
      $this
        ->assertFalse($this
        ->getCacheBackend($bin)
        ->get('test'), 'Tag invalidation affected item in bin.');
    }

    // Test that the cache entry with a matching tag has been invalidated.
    $this
      ->assertFalse($this
      ->getCacheBackend($bin)
      ->get('test_cid_invalidate2'), 'Cache items matching tag were invalidated.');

    // Test that the cache entry with without a matching tag still exists.
    $this
      ->assertTrue($this
      ->getCacheBackend($bin)
      ->get('test_cid_invalidate1'), 'Cache items not matching tag were not invalidated.');
  }

  /**
   * Test Drupal\Core\Cache\CacheBackendInterface::invalidateAll().
   */
  public function testInvalidateAll() {
    $backend = $this
      ->getCacheBackend();

    // Set both expiring and permanent keys.
    $backend
      ->set('test1', 1, CacheBackendInterface::CACHE_PERMANENT);
    $backend
      ->set('test2', 3, time() + 1000);
    $backend
      ->invalidateAll();
    $this
      ->assertFalse($backend
      ->get('test1'), 'First key has been invalidated.');
    $this
      ->assertFalse($backend
      ->get('test2'), 'Second key has been invalidated.');
    $this
      ->assertTrue($backend
      ->get('test1', TRUE), 'First key has not been deleted.');
    $this
      ->assertTrue($backend
      ->get('test2', TRUE), 'Second key has not been deleted.');
  }

}