--- /dev/null
+<?php
+
+namespace Drupal\system\Tests\Ajax;
+
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Provides a base class for Ajax tests.
+ */
+abstract class AjaxTestBase extends WebTestBase {
+
+ /**
+ * Modules to enable.
+ *
+ * @var array
+ */
+ public static $modules = ['node', 'ajax_test', 'ajax_forms_test'];
+
+ /**
+ * Asserts the array of Ajax commands contains the searched command.
+ *
+ * An AjaxResponse object stores an array of Ajax commands. This array
+ * sometimes includes commands automatically provided by the framework in
+ * addition to commands returned by a particular controller. During testing,
+ * we're usually interested that a particular command is present, and don't
+ * care whether other commands precede or follow the one we're interested in.
+ * Additionally, the command we're interested in may include additional data
+ * that we're not interested in. Therefore, this function simply asserts that
+ * one of the commands in $haystack contains all of the keys and values in
+ * $needle. Furthermore, if $needle contains a 'settings' key with an array
+ * value, we simply assert that all keys and values within that array are
+ * present in the command we're checking, and do not consider it a failure if
+ * the actual command contains additional settings that aren't part of
+ * $needle.
+ *
+ * @param $haystack
+ * An array of rendered Ajax commands returned by the server.
+ * @param $needle
+ * Array of info we're expecting in one of those commands.
+ * @param $message
+ * An assertion message.
+ */
+ protected function assertCommand($haystack, $needle, $message) {
+ $found = FALSE;
+ foreach ($haystack as $command) {
+ // If the command has additional settings that we're not testing for, do
+ // not consider that a failure.
+ if (isset($command['settings']) && is_array($command['settings']) && isset($needle['settings']) && is_array($needle['settings'])) {
+ $command['settings'] = array_intersect_key($command['settings'], $needle['settings']);
+ }
+ // If the command has additional data that we're not testing for, do not
+ // consider that a failure. Also, == instead of ===, because we don't
+ // require the key/value pairs to be in any particular order
+ // (http://php.net/manual/language.operators.array.php).
+ if (array_intersect_key($command, $needle) == $needle) {
+ $found = TRUE;
+ break;
+ }
+ }
+ $this->assertTrue($found, $message);
+ }
+
+}