MDL-54751 behat: Support for adhoc module and section deletion in behat

Introduced new behat step for running all pending adhoc tasks and
modified the relavant behat tests.

lib/tests/behat/behat_general.php

@@ -1001,6 +1001,43 @@ class behat_general extends behat_base {
         }
     }
 
+    /**
+     * Runs all ad-hoc tasks in the queue.
+     *
+     * This is faster and more reliable than running cron (running cron won't
+     * work more than once in the same test, for instance). However it is
+     * a little less 'realistic'.
+     *
+     * While the task is running, we suppress mtrace output because it makes
+     * the Behat result look ugly.
+     *
+     * @Given /^I run all adhoc tasks$/
+     * @throws DriverException
+     */
+    public function i_run_all_adhoc_tasks() {
+        // Do setup for cron task.
+        cron_setup_user();
+
+        // Run tasks. Locking is handled by get_next_adhoc_task.
+        $now = time();
+        ob_start(); // Discard task output as not appropriate for Behat output!
+        while (($task = \core\task\manager::get_next_adhoc_task($now)) !== null) {
+
+            try {
+                $task->execute();
+
+                // Mark task complete.
+                \core\task\manager::adhoc_task_complete($task);
+            } catch (Exception $e) {
+                // Mark task failed and throw exception.
+                \core\task\manager::adhoc_task_failed($task);
+                ob_end_clean();
+                throw new DriverException('An adhoc task failed', 0, $e);
+            }
+        }
+        ob_end_clean();
+    }
+
     /**
      * Checks that an element and selector type exists in another element and selector type on the current page.
      *