Testing Android apps with Expo on physical devices

If you’re a web developer and you want to create mobile apps for iOS and Android, then you’ll probably use Expo1. Expo allows you to write React Native2 code and has a full development environment for both iOS and Android, as well as generating a web preview of the same application. Your development build integrates directly with iOS and Android emulators running on your local machine, making it easy to debug and rapidly make changes. However, there’s no replacement for testing on a physical device. For iOS, this is fairly straightforward so long as you’re on a Mac; for Android, it can be a bit trickier. After trying out several approaches, I finally landed on attaching an Android device via USB to the same Windows machine running my Expo development server. This approach gives the device access to localhost, so I can run the API backend locally and have everything work. As a bonus, it even works when the dev server is running in WSL. Step 1: Download and install Android Studio To get…