Expo setup

If needed, there is a guide depending on what you want to build/launch in the Expo documentation

Local build and development

Tooling Requirements

1. node v18+
2. yarn v3
3. Android Studio / Xcode
4. The Expo Go application on your mobile phone

Yarn

To install yarn, run

npm install --global yarn

Run yarn to install dependencies

Launching the app

• Run Expo

yarn start

• Open Expo Go or scan the QR code.
• You can also open the devtool console by typing d in the terminal

Reset the cache

If you changed some environment variable, you might need to reset the cache:

npx expo start --reset-cache

Running on Expo Go with local web

• Run web, copy the lan IP e.g 192.168.x.y
• Update your EXPO_PUBLIC_LOCAL_URI in the .env with the related IP
• Run the mobile app using this command (note the --reset-cache option, it's necessary for Metro to reload the .env file):

npx expo start --reset-cache

• Install Expo Go
• Launch ShapeShift by scanning the QR code
• Select the localhost environment in the settings
• The hotreloading should work as expected

Run the iOS build in a simulator

1. There is an expo command to run the iOS app:

yarn ios

2. If you are struggling launching the simulator, you might want to use the prebuild command which is updating native folders:

yarn prebuild

Run the Android build in a simulator

1. There is an expo command to run the iOS app:

yarn android

Pushing builds to EAS

• Install EAS:

npm install -g eas-cli

• Send both apps:

eas build

Deploying a new version

• Update the version field in the app.json file to the new version
• run npx expo prebuild to build both android and ios bundles and update the versions
• and then deploy a build to eas using eas build

Getting native files to test builds locally using an emulator

• Make sure you have android studio installed, with an emulator, same for iOS with xcode
• First run npx expo prebuild
• Then npx expo start
• Hit i or a depending on which emulator you want to run

Push a workflow job manually

We can launch workflows to deploy an app without relying on the CI:

npx eas-cli@latest workflow:run .eas/workflows/build-and-deploy.yml

It can be useful if we want the operation team to test a specific version before we merge on main.

Autoincrement

EAS supports auto incrementing builds. Every time we submit a build, the patch version will be automatically incremented.

Major or minor versions

1. Update the appVersion and version fields of the app.json file
2. run npx expo prebuild to build both android and ios bundles and update the versions
3. and then deploy a build to eas using eas build

Updating native files

If we add some native library, we will need to prevent the old applications from receiving the Over-The-Air (OTA) updates:

• The process is the same as updating to a major or minor version, but you also need to update the runtimeVersion, which is used by Expo to check if the runtimeVersion of the update is the same as the current OTA. If it differs, the application will not accept the OTA to avoid crash issues due to missing native files.

Allow for OPS to test before releasing an OTA

The more practical way is to update the runtimeVersion and push this particular build to android testing channels and flightests, but this will require a store update.

In the future, if we see that it would be more practical to have a dedicated channel, it would means that OPS team would need to keep the operations app on their phone, we could do a release channel build and update them as OTAs, then rebuild using the production channel, but as far as I know, iPhones can't install both apps at the same time...