Releasing Expo Go for Android

This document will guide you through the process of releasing a new version of Expo Go for Android.

1. Bump versions of Android project

   Why: Every new version of Expo Go has to have another version and version code.

   How: Edit /android/app/build.gradle and bump versions in that file.

2. Add changelog for Play Store

   Why: It's polite to inform users why they may want to upgrade to latest version of an app.

   How: Add a new file under /fastlane/android/metadata/en-US/changelogs/[versionCode].txt (most probably it can read “Add support for SDK XX”).

3. Test the application

   Why: For our convenience it's the CI who builds the APK. Before submitting it anywhere we want to test it properly.

   How: On the release branch (sdk-XX) from which any updates are published, open the client_android job for commit after step 2., download build artifact from under /root/expo/android/app/build/outputs/apk/release/app-versioned-release.apk.

   • Run adb shell pm clear host.exp.exponent
   • Enable airplane mode on the device you'll be testing it on
   • adb install {downloaded-apk}
   • Open the application. Ensure Home loads.
     • known issue: icons don't load in airplane mode
   • Disable airplane mode and test the application.

4. Upload the application to backend for website and expo-cli to download

   Why: So that developers who used expo-cli to download Expo Go to their devices can download the update.

   How:

   • Open CircleCI on the release branch and go to the client workflow. Once client_android job is finished, approve client_android_apk_release_approve job and follow the next job client_android_apk_release which takes and uploads the artifact archive from client_android job to staging.
   • Test if this APK works as expected. Connect Android device to your computer or open up an emulator and then run expotools command et client-install -p android to install and launch an APK.
   • When you're ready to sync the versions change to production, run et promote-versions.

5. Submit the application to Play Store

   Why: So that our users that downloaded Expo Go from Play Store can update easily.

   How: Open the client workflow from which you downloaded app-release.apk in step 3. and approve the client_android_approve_google_play job. About 45 minutes later the update should be downloadable via Play Store.