Android Testing

Testing

Paparazzi: Screenshot Testing for Android Without an Emulator

Paparazzi is a Cash App library that renders Android views and Compose UIs to PNG screenshots on the JVM — no emulator, no device, no ADB. Tests run in seconds instead of minutes. You record a baseline, then any future change that alters the visual output fails the test. This is

Testing

Testing Android ViewModels with Kotlin Flow, Turbine, and Coroutines

ViewModels are the core of Android architecture: they hold state, handle business logic, and expose data via Kotlin Flow. Testing them thoroughly — including loading states, error handling, and side effects — requires understanding how to control coroutines and observe Flow emissions in tests. This guide covers ViewModel testing with TestDispatcher, Turbine