Add tests.

Author: dereuromark

README.md

@@ -87,9 +87,7 @@ Supported class types:
 * [x] Forms
 * [x] Mailers
 
-Feel free to help out improving and completing this test helper plugin.
-
-* [Full Documentation](docs/README.md)
+[Full Documentation](docs/README.md)
 
 ## Custom Linter Tasks
 

src/Controller/TestHelperController.php

@@ -38,7 +38,7 @@ public function index() {
 
 		$plugins = Plugin::loaded();
 
-		$namespace = $this->request->getQuery('plugin');
+		$namespace = (string)$this->request->getQuery('plugin') ?: null;
 		if ($namespace && !in_array($namespace, $plugins, true)) {
 			$this->Flash->error('Invalid plugin');