Figure out if we still need immutable MessageEvent

<script src='wsHook.js'></script>

Define your custom before and after hooks on the globally exposed wsHook object.

wsHook.before = function(data, url, wsObject) {
    console.log("Sending message to " + url + " : " + data);
}

// Make sure your program calls `wsClient.onmessage` event handler somewhere.
wsHook.after = function(messageEvent, url, wsObject) {
    console.log("Received message from " + url + " : " + messageEvent.data);
    return messageEvent;
}

// if you do not want to propagate the MessageEvent further down, just return null
wsHook.after = function(messageEvent, url, wsObject) {
 console.log("Received message from " + url + " : " + messageEvent.data);
 // This example can ping-pong forever, so maybe use some conditions
 wsObject.send("Intercepted and sent again")
 return null;
}

var wsClient = new WebSocket("wss://echo.websocket.org");

wsClient.onopen = function() {
    wsClient.send("Echo this");
}

wsClient.onmessage = function(e){
  console.log(e);
}

Invoked just before calling the actual WebSocket's send() method.

This method must return data which can be modified as well.

Invoked just after receiving the MessageEvent from the WebSocket server and before calling the WebSocket's onmessage Event Handler.

This method must return event whose properties can be modified as well. You might be interested in modiying, event.data or event.origin usually.

The wsObject refers to the corresponding WebSocket object used. You can use this to send a message to the server. This allows one to fully hijack the WebSocket connection programatically.

If you do not want the user's original onmessage event handler to be called, just return null.

// Load wsHook.js
// Define the 'before' and 'after' hooks as you wish.

wsHook.before = function(data, url, wsObject){
  data += "_modified";
  console.log("Modifying data to " + data);
  return data;
}

var wsClient = new WebSocket("wss://echo.websocket.org");
wsClient.onopen = function() {
  wsClient.send("Echo this");
}
wsClient.onmessage = function(e){
  console.log(e);
}

• Hookish: Hooks in to interesting functions and helps reverse the web app faster.

• Test cases for common WebSocket libraries.

The MIT License (MIT)

Copyright (c) 2015 Ahamed Nafeez

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

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