MDL-74636 behat: step to skip this scenario if a plugin isn't installed

lib/tests/behat/behat_general.php

@@ -1988,6 +1988,21 @@ public function database_family_used_is_one_of_the_following(TableNode $database
         throw new \Moodle\BehatExtension\Exception\SkippedException();
     }
 
+    /**
+     * Checks if given plugin is installed, and skips the current scenario if not.
+     *
+     * @Given the :plugin plugin is installed
+     * @param string $plugin frankenstyle plugin name, e.g. 'filter_embedquestion'.
+     * @throws \Moodle\BehatExtension\Exception\SkippedException
+     */
+    public function plugin_is_installed(string $plugin): void {
+        $path = core_component::get_component_directory($plugin);
+        if (!is_readable($path . '/version.php')) {
+            throw new \Moodle\BehatExtension\Exception\SkippedException(
+                    'Skipping this scenario because the ' . $plugin . ' is not installed.');
+        }
+    }
+
     /**
      * Checks focus is with the given element.
      *