Develop, Deploy and Test React Native apps with Expo

08 Oct Develop, Deploy and Test React Native apps with Expo

What’s Expo?

Expo is a set of tools, libraries, and services which let you build native iOS and Android apps by writing JavaScript.

Expo apps are React Native apps which contain the Expo SDK. The SDK is a native-and-JS library which provides access to the device's system functionality (things like the camera, contacts, local storage, and other hardware). That means you don't need to use Xcode or Android Studio, or write any native code, and it also makes your pure-JS project very portable because it can run in any native environment containing the Expo SDK.

Installation

There are two tools that you need to develop apps with Expo: a local development tool and a mobile client to open your app.

Local Development Tool: Expo CLI

npm install -g expo-cli

{
  "expo": {
  "name": "Your App Name",
  "icon": "./path/to/your/app-icon.png",
  "version": "1.0.0",
  "slug": "your-app-slug",
  "sdkVersion": "XX.0.0",
  "ios": {
    "bundleIdentifier": "com.yourcompany.yourappname"
  },
  "android": {
    "package": "com.yourcompany.yourappname"
    }
  }
}

cd AwesomeProject
expo start

On Expo Dev Tools, we can run on Android device/ emulator or iOS simulator. Here is a brief breakdown of the new browser experience:

• It’s easy to view logs from multiple devices simultaneously.
• We made switching connections and connecting to your devices easier to navigate. There are three options: localhost, LAN, and Tunnel.
• We’ll let you know if you lose your network connection.
• More clarity around issues and warnings to help you through annoying situations.
• You can still scan a QR code or send a link to your project to your phone.
• The Publish step acts as a guide to help you keep your published project pages looking sharp

Deploy

Start the build

Run expo build:android or expo build:ios. If you don't already have a packager running for this project, exp will start one for you.

Note: If you choose the first option and later decide to upload your own keystore, we currently offer an option to clear your current Android keystore from our build servers by running expo build:android --clear-credentials. This is irreversible, so only run this command if you know what you are doing! You can download a backup copy of the keystore by running expo fetch:android:keystore. If you do not have a local copy of your keystore , you will be unable to publish new versions of your app to the Play Store. Your only option would be to generate a new keystore and re-upload your application as a new application. You can learn more about how code signing and keystores work in the Android documentation.




Publish

Testing your React Native apps on real devices

In this part, I will guide you how to use Kobiton Cloud to test your apps. A Kobiton account is required to access Kobiton system. If you do not have a Kobiton account yet, go ahead to create a free trial account and sign in. It takes just a few moments.

• Uploading Mobile Apps to Kobiton Store for Testing
  • Navigate to https://portal.kobiton.com/apps and upload your apps
  • 
  • The file extension can be .apk, .ipa or .zip
  • The file size exceeds 500mb
  •  Select menu to view Automation snippet code
  • 
• Launch a manual test with your expected device
  • Navigate to https://portal.kobiton.com/devices and launch your device
  • 
  • Select APPS tab and install your app into the real device
  • 
  • We have several ways to install an app. Another way is from your local file or from public URL.
• Modify your desiredCaps to automate your app with the expected device
  • You can set your test to reference the application at the Kobiton Storage URL with the app capability, as shown in this example for Java.

  • DesiredCapabilities capabilities = new DesiredCapabilities();
    capabilities.setCapability("app", "kobiton-store:1024"); 
    capabilities.setCapability("deviceGroup", "KOBITON"); 
    capabilities.setCapability("deviceName", "Galaxy S8+");
    capabilities.setCapability("platformVersion", "7.0");
    capabilities.setCapability("platformName", "Android");