How to get results from an async Javascript script using C# and Microsoft WebView2 control?

Using helpful comments and hints from Phil and Jimi I have compiled a generic solution for my original Javascript script. Here I'm posting a bit more simplified but fully functional solution. The software versions I've used for the solution are .NET 9 (.NET Runtimes 9.0.4, .NET SDK 9.0.201) and Microsoft.Web.WebView2 v.1.0.3179.45.

1. Solution code

   public static async Task<string> ExecuteAsyncJSScriptAsync(
              Microsoft.Web.WebView2.WinForms.WebView2 wv,
              string jsScript,
              Func<string, Task> log,
              int timeOutInSeconds = 10)
   {
       var sw = Stopwatch.StartNew();
   
       ManualResetEvent waitFlag = new ManualResetEvent(false);
       var ipAddress = "";
       var timeOut = false;
       var timeOutTimer = new System.Timers.Timer(timeOutInSeconds)
       {
           Interval = timeOutInSeconds * 1000
       };
       timeOutTimer.Elapsed += new System.Timers.ElapsedEventHandler((sender, e) =>
       {
           timeOut = true;
           timeOutTimer.Stop();
           waitFlag.Set();
       });
       timeOutTimer.Start();
   
       if (!wv.CoreWebView2.Settings.IsWebMessageEnabled) wv.CoreWebView2.Settings.IsWebMessageEnabled = true;
       if (!wv.CoreWebView2.Settings.IsScriptEnabled) wv.CoreWebView2.Settings.IsScriptEnabled = true;
   
       var webMessageReceiveEventHandler = new EventHandler<CoreWebView2WebMessageReceivedEventArgs>(
               async (sender, args) =>
               {
                   var ipMessagePrefix = "ip => ";
                   var message = args.TryGetWebMessageAsString();
                   if (message.StartsWith(ipMessagePrefix))
                   {
                       await log($"webMessageReceived: IP found = {message}");
                       ipAddress = message.Substring(ipMessagePrefix.Length);
                   }
                   else
                   {
                       await log($"webMessageReceived: Message = {message}");
                   }
   
                   waitFlag.Set();
               }
               );
   
       try
       {
           wv.WebMessageReceived += webMessageReceiveEventHandler;
   
           await wv.ExecuteScriptAsync(jsScript);
   
           await log($"async JS execution activated, non-blocking wait started, elapsed = {sw.Elapsed.TotalSeconds:0.000}s");
   
           await Task.Run(() => waitFlag.WaitOne());
   
           await log($"Non-blocking wait completed, elapsed = {sw.Elapsed.TotalSeconds:0.000}s");
       }
       finally
       {
           wv.WebMessageReceived -= webMessageReceiveEventHandler;
           timeOutTimer.Dispose();
           waitFlag.Dispose();
       }
   
       await log($"ExecuteAsyncJSScriptAsync completed, elapsed = {sw.Elapsed.TotalSeconds:0.000}s");
   
       if (timeOut)
       {
           var errorMessage = "Error: Failed to execute async JS script - time-out";
           await log(errorMessage);
           return errorMessage;
       }
   
       return ipAddress;
   }
   

2. GetIPAddress JS Script

Hint: to make window.chrome.webview.postMessage(...) fired on C# client code side the JS Script should be "wrapped" into Promise.resolve(...).

    private string getIPAddressJsScript =>
    @"
        Promise.resolve(
        (async function getIPAddress() {
            data = await (await fetch('https://api.ipify.org?format=json')).json();
            ip = data.ip;
            window.chrome.webview.postMessage(`ip => ${ip}`);
            return ip;
        })());
    ";

3. GetIPAddress method

   public async Task<string> GetIPAddress(
                Microsoft.Web.WebView2.WinForms.WebView2 wv, 
                Func<string, Task> log)
   {
       return await ExecuteAsyncJSScriptAsync(wv, getIPAddressJsScript, log);
   }
   

4. Test run log

  async JS execution activated, non-blocking wait started, elapsed = 0.001s
  webMessageReceived: IP found = 119.13.224.44
  Non-blocking wait completed, elapsed = 0.662s
  ExecuteAsyncJSScriptAsync completed, elapsed = 0.664s

Please comment on this solution to improve it.

P.S. Of course WebView2 has to be initialized before using the solution code, e.g:

 await webView2InstanceRef.EnsureCoreWebView2Async(
     await CoreWebView2Environment.CreateAsync(null, null));