Fiddler script to search within websocket messages

searchws.js

// Adds QuickExec command `searchws <string>` to search the string inside websocket messages on all current Fiddler websocket sessions
// It also adds a column to the sessions `WS Search` reporting on how many hits for <string> were found on each session,
// and logs to the standard log tab in what messages of which session was the <string> found.

// This script may be copied as-is to replace all the contents in Fiddler > Rules > Customize Rules editor,
// or its contents can be added to the script already found there.

import System;
import System.Windows.Forms;
import Fiddler;

class Handlers
{
	public static BindUIColumn("WS Search")
	function WsSearchCol(oS: Session){
		if (null != oS["custom-ws-search"]) return oS["custom-ws-search"]; else return String.Empty; 
	}
			
	static function OnExecAction(sParams: String[]): Boolean {

		FiddlerObject.StatusText = "ExecAction: " + sParams[0];

		var sAction = sParams[0].toLowerCase();
		switch (sAction) {
			case "searchws":
				if (sParams.Length<2) { FiddlerObject.StatusText="Please specify a string to search for"; return false;}
				const searchString = sParams[1]
				var webSocketCounter = 0;
				var foundTotalCounter = 0;

				const oSessions : Session[] = UI.GetAllSessions();
				for (var sessionIdx:int = 0; sessionIdx < oSessions.Length; sessionIdx++){
					var currSession = oSessions[sessionIdx];                    
                    
					if(currSession.bHasWebSocketMessages){
						webSocketCounter += 1;
						currSession["custom-ws-search"] = String.Empty;                        
						const currWebSocketTunnel : WebSocket = (WebSocket) (currSession.__oTunnel); // couldnt find a cleaner way to get the websocket tunnel from the session...
                        
						var foundInSessionCounter = 0;
						for(var wsMessageIdx : int = 0; wsMessageIdx < currWebSocketTunnel.MessageCount; wsMessageIdx++)
						{
							const wsMessage = currWebSocketTunnel.listMessages[wsMessageIdx];
							const wsType = wsMessage.FrameType;
							if(wsType != WebSocketFrameTypes.Ping && wsType != WebSocketFrameTypes.Pong) // don't search in ping-pong messages
							{
								const wsPayload = wsMessage.PayloadAsString();
								//FiddlerObject.log(wsPayload);
								if(wsPayload.search(searchString) != -1)
								{
									FiddlerObject.log("Found " + searchString + " in Session #" + currSession.id + " WSMessage #" + wsMessage.ID);
									foundTotalCounter += 1
									foundInSessionCounter += 1;
								}   
                                
							}
						}
                        
						if(foundInSessionCounter > 0)
						{
							currSession["custom-ws-search"] = "FOUND " + foundInSessionCounter + " messages containing \"" + searchString + "\"";
						}
						currSession.RefreshUI();
					}
				}
                
				FiddlerObject.StatusText = "Found " + foundTotalCounter + " total hits on " + webSocketCounter + " Websocket tunnels";
				return true;
			
			default:
				FiddlerObject.StatusText = "Requested ExecAction: '" + sAction + "' not found. Type HELP to learn more.";
				return false;
		}
	}
}