Failure modes

Airplane Mode

Takes one app offline. In the iOS Simulator it behaves like a real device for apps launched with request monitoring:

• requests fail with “The Internet connection appears to be offline”,
• NWPathMonitor reports no network,
• SCNetworkReachability (used by Alamofire and Reachability.swift) reports no network.

Connection failures

• Refuse connections: refuse a percentage of new connections.
• Time out: every request times out.
• Drop connections: drop connections after a number of seconds.
• Outages: go offline and come back, repeatedly.

Fail or mock one endpoint

In simulator apps, pick an endpoint and make it go offline, time out, return an HTTP status or respond with a delay, or mock it with a made-up response starting from the real one. The rest of the app keeps working. More about mocking endpoints.