Rename websocket.js to websocket.sub.js. This makes it impossible to forget the substitution. 
diff --git a/websockets/Secure-Close-string.htm b/websockets/Secure-Close-string.htm index 20dffe1..64bf16b 100644 --- a/websockets/Secure-Close-string.htm +++ b/websockets/Secure-Close-string.htm 
@@ -4,7 +4,7 @@  <title>W3C WebSocket API - Close Secure WebSocket - Code is string</title>  <script type="text/javascript" src="/resources/testharness.js"></script>  <script type="text/javascript" src="/resources/testharnessreport.js"></script> - <script type="text/javascript" src="websocket.js?pipe=sub"></script> + <script type="text/javascript" src="websocket.sub.js"></script>  </head>  <body>  <div id="log"></div>