--- /dev/null
+<?php
+
+namespace Drupal\system\Tests\Common;
+
+use Drupal\language\Entity\ConfigurableLanguage;
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests the format_date() function.
+ *
+ * @group Common
+ */
+class FormatDateTest extends WebTestBase {
+
+ /**
+ * Modules to enable.
+ *
+ * @var array
+ */
+ public static $modules = ['language'];
+
+ /**
+ * Arbitrary langcode for a custom language.
+ */
+ const LANGCODE = 'xx';
+
+ protected function setUp() {
+ parent::setUp('language');
+
+ $this->config('system.date')
+ ->set('timezone.user.configurable', 1)
+ ->save();
+ $formats = $this->container->get('entity.manager')
+ ->getStorage('date_format')
+ ->loadMultiple(['long', 'medium', 'short']);
+ $formats['long']->setPattern('l, j. F Y - G:i')->save();
+ $formats['medium']->setPattern('j. F Y - G:i')->save();
+ $formats['short']->setPattern('Y M j - g:ia')->save();
+ $this->refreshVariables();
+
+ $this->settingsSet('locale_custom_strings_' . self::LANGCODE, [
+ '' => ['Sunday' => 'domingo'],
+ 'Long month name' => ['March' => 'marzo'],
+ ]);
+
+ ConfigurableLanguage::createFromLangcode(static::LANGCODE)->save();
+ $this->resetAll();
+ }
+
+ /**
+ * Tests admin-defined formats in format_date().
+ */
+ public function testAdminDefinedFormatDate() {
+ // Create and log in an admin user.
+ $this->drupalLogin($this->drupalCreateUser(['administer site configuration']));
+
+ // Add new date format.
+ $edit = [
+ 'id' => 'example_style',
+ 'label' => 'Example Style',
+ 'date_format_pattern' => 'j M y',
+ ];
+ $this->drupalPostForm('admin/config/regional/date-time/formats/add', $edit, t('Add format'));
+
+ // Add a second date format with a different case than the first.
+ $edit = [
+ 'id' => 'example_style_uppercase',
+ 'label' => 'Example Style Uppercase',
+ 'date_format_pattern' => 'j M Y',
+ ];
+ $this->drupalPostForm('admin/config/regional/date-time/formats/add', $edit, t('Add format'));
+ $this->assertText(t('Custom date format added.'));
+
+ $timestamp = strtotime('2007-03-10T00:00:00+00:00');
+ $this->assertIdentical(format_date($timestamp, 'example_style', '', 'America/Los_Angeles'), '9 Mar 07');
+ $this->assertIdentical(format_date($timestamp, 'example_style_uppercase', '', 'America/Los_Angeles'), '9 Mar 2007');
+ $this->assertIdentical(format_date($timestamp, 'undefined_style'), format_date($timestamp, 'fallback'), 'Test format_date() defaulting to `fallback` when $type not found.');
+ }
+
+}