Detox + Jest + Ejected Expo application

This is an example of ejected Expo application integrated with Detox + Jest, using jest-circus runner.

The tests run on the app's production version, which must be built with yarn detox-build:release before running the tests with yarn detox-test:release

Setup

Mac OS

Java

On MacOS, to install OpenJDK 8, run the following:

brew tap adoptopenjdk/openjdk
brew cask install adoptopenjdk8
java -version

A window will pop-up saying that java is asking for file access permissions. Allow it and you should be ready to go!

Android SDK

After installing, you must add it to path, like so:

printf '\nexport ANDROID_HOME=/Users/"$USER"/Library/Android/sdk\nexport ANDROID_SDK_ROOT=$ANDROID_HOME\n' >> ~/.bash_profile

Issues I had when setting up Detox environment

OpenJDK 8

Detox + Expo currently depende on Java 1.8 or OpenJDK 8

On MacOS, to install OpenJDK 8, run the following:

brew tap adoptopenjdk/openjdk
brew cask install adoptopenjdk8
java -version

A window will pop-up saying that java is asking for file access permissions. Allow it and you should be ready to go!

Use an open source emulator

Follow the instructions for installing as per Detox documentation

Error while dexing

Solved by limiting gradlew tasks to the app project, by adding app prefix to build command on .detoxrc.json:

- "build": "cd android && ./gradlew assembleRelease assembleAndroidTest -DtestBuildType=release && cd ..",
+ "build": "cd android && ./gradlew app:assembleRelease app:assembleAndroidTest -DtestBuildType=release && cd ..",

Source on StackOverflow

App has not responded to the network requests below: (id = -1000) isReady: {}

To solve this issue, I had to build and run the tests on the production version of the app. To do this, just change binaryPath and DtestBuildType on .detoxrc.json:

- "binaryPath": "android/app/build/outputs/apk/debug/app-debug.apk",
- "build": "cd android && ./gradlew assembleDebug assembleAndroidTest -DtestBuildType=debug && cd ..",
+ "binaryPath": "android/app/build/outputs/apk/release/app-release.apk",
+ "build": "cd android && ./gradlew assembleRelease assembleAndroidTest -DtestBuildType=release && cd ..",

Source on StackOverflow

Kotlin gradle Could not initialize class class org.jetbrains.kotlin.gradle.internal.KotlinSourceSetProviderImplKt

For this one I just had to change my Kotlin version:

buildscript {
    ext {
-       kotlinVersion = '1.3.0'
+       kotlinVersion = '1.3.72'
    }
}

Source on StackOverflow

Expiring Daemon because JVM heap space is exhausted

To solve this I needed to change gradle.properties and app/build.gradle to allow for more memory usage by JVM:

gradle.properties

  android.useAndroidX=true
  android.enableJetifier=true
+ org.gradle.jvmargs=-Xmx4g -XX:MaxPermSize=2048m -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8

app/build.gradle

android {

+ dexOptions {
+   javaMaxHeapSize "4g"
+ }

}

Source on StackOverflow

App Crashing

If you get an invariant error in iOS talking about "Safe Area" or an Android error like the one below:

09-14 12:38:26.343  5648  5672 E AndroidRuntime: FATAL EXCEPTION: mqt_native_modules
09-14 12:38:26.343  5648  5672 E AndroidRuntime: Process: com.vagners.expoapp, PID: 5648
09-14 12:38:26.343  5648  5672 E AndroidRuntime: com.facebook.react.common.JavascriptException: Invariant Violation: requireNativeComponent: "RNCSafeAreaProvider" was not found in the UIManager.

That means that you should verify the react-native-safe-area-context library version. Run:

yarn why react-native-safe-area-context

It should show a single installed package. If expo is using a different version, update the package.json version to match it (in the case of this prototype, we had to set it to @3.0.7). Having this dep duplicated will result in errors and different behavior between iOS and Android, so always check on both if/when you update this package's version.