I'd like to set up a communication mechanism between the Ui test runner and my iOS app. The purpose is to be able to collect some custom performance metrics in addition to standard ones like scrollingAndDecelerationMetric. Let's say we measure some specific intervals in our code using signposts, then serialize the result into a structured payload and report it back to the runner.
So, are there any good options for that kind of IPC?
The primary concern is running on Simulator. However, since it is not a regular UI test but more a performance UI test, and it is usually recommended to run those on a real device, with release optimizations/flags in place, I wonder if it is feasible to have it for device too.
appaul
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution
Post
Replies
Boosts
Views
Activity
My team are now testing http/3 support in our app and backend. It looks strange to me how the behaviour is different between iOS 15.7.3 and 16.x (now 16.6).
It is a default URLSession config and just a regular URLRequest, with no assumesHTTP3Capable flag set. I observe the protocol in use with both collecting URLSessionTaskMetrics and the Network instrument.
On 15.7.3 the 1st request is done using h2, the network subsystem caches the Alt-Svc header (per host I suppose). Several seconds pass and then when I issue the same 2nd request a new connection is established and the protocol is upgraded to h3. This is all fine and as described in the documentation or wwdc videos.
However, when I take the same steps with a device running e.g. iOS 16.5.1 I see that the protocol is never upgraded to h3. Neither a longer timeout nor an app relaunch make any difference.
Interestingly, on my Ventura desktop the same url is also handled differently: h3 by Chrome but always h2 by Safari. In the mobile Safari on iOS 16, I'm also always shown HTTP/2 on e.g. the cloudflare status page for QUIC.
What can be the reason for such behaviour on iOS 16 and Apple platforms in general?
PS. I've tried running the app with CFNETWORK_DIAGNOSTICS but found no useful log messages to clarify problems with QUIC. Is there still a way to better diagnose such a problem?