diff --git a/core/tests/Drupal/Tests/BrowserTestBase.php b/core/tests/Drupal/Tests/BrowserTestBase.php
index 754f9d9..0f8c57c 100644
--- a/core/tests/Drupal/Tests/BrowserTestBase.php
+++ b/core/tests/Drupal/Tests/BrowserTestBase.php
@@ -651,6 +651,43 @@ protected function drupalGet($path, array $options = [], array $headers = []) {
   }
 
   /**
+   * Retrieves a Drupal path or an absolute path and JSON decodes the result.
+   *
+   * @param \Drupal\Core\Url|string $path
+   *   Drupal path or URL to request AJAX from.
+   * @param array $options
+   *   Array of URL options.
+   * @param array $headers
+   *   Array of headers. Eg array('Accept: application/vnd.drupal-ajax').
+   *
+   * @return array
+   *   Decoded json.
+   */
+  protected function drupalGetJSON($path, array $options = [], array $headers = []) {
+    return Json::decode($this->drupalGetWithFormat($path, 'json', $options, $headers));
+  }
+
+  /**
+   * Retrieves a Drupal path or an absolute path for a given format.
+   *
+   * @param \Drupal\Core\Url|string $path
+   *   Drupal path or URL to request given format from.
+   * @param string $format
+   *   The wanted request format.
+   * @param array $options
+   *   Array of URL options.
+   * @param array $headers
+   *   Array of headers.
+   *
+   * @return mixed
+   *   The result of the request.
+   */
+  protected function drupalGetWithFormat($path, $format, array $options = [], array $headers = []) {
+    $options += ['query' => ['_format' => $format]];
+    return $this->drupalGet($path, $options, $headers);
+  }
+
+  /**
    * Takes a path and returns an absolute path.
    *
    * @param string $path