diff --git a/core/modules/simpletest/tests/src/Functional/BrowserTestBaseTest.php b/core/modules/simpletest/tests/src/Functional/BrowserTestBaseTest.php
index 796360f..4d1906e 100644
--- a/core/modules/simpletest/tests/src/Functional/BrowserTestBaseTest.php
+++ b/core/modules/simpletest/tests/src/Functional/BrowserTestBaseTest.php
@@ -36,6 +36,10 @@ public function testGoTo() {
     // Response includes cache tags that we can assert.
     $this->assertSession()->responseHeaderEquals('X-Drupal-Cache-Tags', 'rendered');
 
+    // Test that we can read the JS settings.
+    $js_settings = $this->getDrupalSettings();
+    $this->assertSame('azAZ09();.,\\\/-_{}', $js_settings['test-setting']);
+
     // Test drupalGet with a url object.
     $url = Url::fromRoute('test_page_test.render_title');
     $this->drupalGet($url);
diff --git a/core/tests/Drupal/Tests/BrowserTestBase.php b/core/tests/Drupal/Tests/BrowserTestBase.php
index 3beb32f..c0a82d0 100644
--- a/core/tests/Drupal/Tests/BrowserTestBase.php
+++ b/core/tests/Drupal/Tests/BrowserTestBase.php
@@ -7,6 +7,7 @@
 use Behat\Mink\Mink;
 use Behat\Mink\Session;
 use Drupal\Component\FileCache\FileCacheFactory;
+use Drupal\Component\Serialization\Json;
 use Drupal\Component\Serialization\Yaml;
 use Drupal\Component\Utility\Html;
 use Drupal\Component\Utility\SafeMarkup;
@@ -1768,6 +1769,20 @@ protected function getUrl() {
   }
 
   /**
+   * Gets the JavaScript drupalSettings variable for the currently-loaded page.
+   *
+   * @return array
+   *   The JSON decoded drupalSettings value from the current page.
+   */
+  protected function getDrupalSettings() {
+    $html = $this->getSession()->getPage()->getHtml();
+    if (preg_match('@<script type="application/json" data-drupal-selector="drupal-settings-json">([^<]*)</script>@', $html, $matches)) {
+      return Json::decode($matches[1]);
+    }
+    return [];
+  }
+
+  /**
    * {@inheritdoc}
    */
   public static function assertEquals($expected, $actual, $message = '', $delta = 0.0, $maxDepth = 10, $canonicalize = FALSE, $ignoreCase = FALSE) {