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Staying With Expo

This guide will teach you how to set up an Expo development build which prepares your project for native code via Config Plugins, but keeps you in Expo's managed workflow.

Appetizer​

Follow the Pristine Expo Project recipe first to make sure you're starting with an Expo only project.

You'll also need eas-cli globally installed and and an Expo account if you don't already have one.

npm install -g eas-cli

Optional: You can use EAS builds for free, however there is a queue time to wait for your build. It is possible to build locally, however you'll need a couple of other dependencies installed for proper iOS and Android builds (if you can already build iOS/Android natively, you're probably good to go!)

iOS
brew install cocoapods fastlane
Android

SDK and NDK

Steps​

1. Project Setup​

From within your project directory, run the following:

yarn add expo-dev-client

Create or link an EAS project.

eas init
✔ Linked to project @infinitered/cookbook
✔ Linked app.json to project with ID 012aaaa3-4ce5-4bae-9f4d-2f842489f07a

Configure the project to support EAS Build.

eas build:configure

2. Build Profile​

Modify the newly generated eas.json to configure a preview build profile

{
  "cli": {
    "version": ">= 0.60.0"
  },
  "build": {
    "development": {
      "developmentClient": true,
      "distribution": "internal"
    },
    "preview": {
      "developmentClient": true,
      "ios": {
        "simulator": true
      }
    },
    "production": {}
  },
  "submit": {
    "production": {}
  }
}

3. Run the Build!​

Using EAS build servers

eas build --profile preview

Once complete, you can download the Android apk or iOS tar file.

Build Locally

eas build --profile preview --local

Your app will be saved in the root directory unless you specify the desired directory with the environment variable EAS_LOCAL_BUILD_ARTIFACTS_DIR, for example:

EAS_LOCAL_BUILD_ARTIFACTS_DIR=build eas build --profile preview --local

This will save your *.apk or *.tar.gz (containing the .app) in the [project-dir]/build/ directory.

4. Run the Development Client​

With the builds complete, let's add them to your emulator or simulator.

iOS
  • tar zxvf build/build-*.tar.gz -C build/ (adapt this command depending on where you saved it to)
  • Drag the PizzaApp.app onto your iOS simulator
Android

Drag the APK onto your emulator or install it on a device (making sure your settings are appropriate for "Install unknown apps")

You can now develop locally like you normally would with Expo Go, with one last adjustment to the start script.

In package.json modify the start script to use the expo-dev-client package.

--"start": "expo start"
++"start": "expo start --dev-client"

Run yarn start in your terminal so metro starts up. Follow the Expo CLI to boot up either the Android or iOS app. You'll notice Expo Go has not launched in this case, but something that looks very similar (you can still shake the device for developer menu, etc).