Added test to ensure view parser plugins works when defined as closure.

tests/system/View/ParserTest.php

@@ -747,6 +747,25 @@ public function testParserPluginNoParams()
 
 	//--------------------------------------------------------------------
 
+	/**
+	 * @group parserplugins
+	 */
+	public function testParserPluginClosure()
+	{
+		$config                   = $this->config;
+		$config->plugins['hello'] = function (array $params = []) {
+			return 'Hello, ' . trim($params[0]);
+		};
+
+		$parser = new Parser($config, $this->viewsDir, $this->loader);
+
+		$template = '{+ hello world +}';
+
+		$this->assertEquals('Hello, world', $parser->renderString($template));
+	}
+
+	//--------------------------------------------------------------------
+
 	/**
 	 * @group parserplugins
 	 */