Issue #2780549 by andrewbelcher, alexpott, mpdonadio:...

Issue #2780549 by andrewbelcher, alexpott, mpdonadio: FormattedDateDiff::$maxAge never applied to caches

core/lib/Drupal/Core/Datetime/FormattedDateDiff.php

@@ -51,9 +51,9 @@ public function getString() {
   }
 
   /**
-   * @return int
+   * {@inheritdoc}
    */
-  public function getMaxAge() {
+  public function getCacheMaxAge() {
     return $this->maxAge;
   }
 

core/tests/Drupal/Tests/Core/Datetime/DateTest.php

@@ -2,6 +2,7 @@
 
 namespace Drupal\Tests\Core\Datetime;
 
+use Drupal\Core\Cache\CacheableMetadata;
 use Drupal\Core\Datetime\DateFormatter;
 use Drupal\Core\Datetime\FormattedDateDiff;
 use Drupal\Core\DependencyInjection\ContainerBuilder;
@@ -392,6 +393,36 @@ public function providerTestFormatDiff() {
     return $data;
   }
 
+  /**
+   * Tests FormattedDateDiff.
+   *
+   * @covers \Drupal\Core\Datetime\FormattedDateDiff::toRenderable
+   * @covers \Drupal\Core\Datetime\FormattedDateDiff::getString
+   * @covers \Drupal\Core\Datetime\FormattedDateDiff::getCacheMaxAge
+   */
+  public function testFormattedDateDiff() {
+    $string = '10 minutes';
+    $max_age = 60;
+    $object = new FormattedDateDiff($string, $max_age);
+
+    // Test conversion to a render array.
+    $expected = [
+      '#markup' => $string,
+      '#cache' => [
+        'max-age' => $max_age,
+      ],
+    ];
+    $this->assertArrayEquals($expected, $object->toRenderable());
+
+    // Test retrieving the formatted time difference string.
+    $this->assertEquals($string, $object->getString());
+
+    // Test applying cacheability data to an existing build.
+    $build = [];
+    CacheableMetadata::createFromObject($object)->applyTo($build);
+    $this->assertEquals($max_age, $build['#cache']['max-age']);
+  }
+
   /**
    * Creates a UNIX timestamp given a date and time string in the format
    * year-month-day hour:minute:seconds (e.g. 2013-12-11 10:09:08).