This app can be used to manually test gRPC under changing network conditions.

It makes RPCs in a loop, logging when the request is sent and the response is received.

To test on the simulator, run pod install, open the workspace created by Cocoapods, and run the app. Once running, disable WiFi (or ethernet) in your computer, then enable it again after a while. Don‘t bother with the simulator’s WiFi or cell settings, as they have no effect: Simulator apps are just Mac apps running within the simulator UI.

The expected result is to never see a “hanged” RPC: success or failure should happen almost immediately after sending the request. Symptom of a hanged RPC is a log like the following being the last in your console:

2016-06-29 16:51:29.443 ConnectivityTestingApp[73129:3567949] Sending request.