Trace missing in Fiddler

[tongyuze]

Hi there,

I have a question while integrate the webview2 with our library. When I try to use fiddler to capture the network trace from the network request, there will be some redirect sessions missing during the process.

Is there any special settings that I need to change in fiddler tool?

[champnic]

Hey @tongyuze, it's possible there's something else you need to do, but my expectation is that it should match the browser behavior. If you run your scenario in the Edge or Chrome browsers, do you see the missing redirects?

[ericlaw1979]

Hi. Fiddler developer here. Fiddler shows all of the network requests it receives unless you configure rules to hide requests. One thing you can do to verify that you're not unexpectedly hiding any requests is to use the Help > Troubleshoot command to cause Fiddler to render any requests that would be hidden in a strikethrough font.

Keep in mind that redirects can be cached by the browser; if the browser uses a previously cached redirect, that request isn't sent to the network and thus it's not visible to Fiddler.

Note that you can also configure your WebView2-based application to capture Chromium NetLogs[1], which you can then import[2] into Fiddler for easy viewing. The advantage there is that the NetLog contains requests that are serviced from the Chromium cache.

[1] https://textslashplain.com/2020/01/17/capture-network-logs-from-edge-and-chrome/#:~:text=WebView2%2Dbased%20applications
[2] https://textslashplain.com/2020/04/08/analyzing-network-traffic-logs-netlog-json/

[jasonxz]

I'm having the same problem...even with Troubleshooting turned on, I'm not seeing traces through Fiddler. I'll see the initial request for a document but none of the javascript or image requests appear.

But my big issue is that I need the AutoResponder functionality in Fiddler to redirect requests to local debugging files and I can't do that if those requests are never making it to Fiddler. Furthermore, b/c my instance of WebView2 isn't actually added to the Visual Tree until after the managed code receives an OK from the scripts that run in the browser, I can't use the Override functionality in the DevTools, either, b/c there's no way for me to accept the popup that's required for Override permissions. The script changes that I'm trying to test center around moving from WebView to WebView2 so, without being able to use my local scripts, the scripts can't talk to the managed code to tell it to go ahead with inserting the WebView2 into the Visual Tree.

[ericlaw1979]

@jasonxz: Have you confirmed that your WebView2 isn't simply reusing cached responses, either from the HTTP Disk Cache, or from a ServiceWorker that uses the Caching API?

[jasonxz]

@ericlaw1979 No, I have not. That seems like the simplest and most-likely explanation. So, how do I go about verifying that and, if that is the problem, how do I get around it?

[ericlaw1979]

@jasonxz I think the simple way to start would be trying to clear the cache for your instance; I don't know much about WV2 but it does not seem hard: #299