# Detox (E2E) test automation

> How to run Detox tests with codemagic.yaml



Detox testing refers to end-to-end (E2E) testing for React Native apps using the Detox framework. Detox provides a gray box testing solution, meaning it runs tests on a real device or emulator while also accessing the app's internal state for better synchronization.


## Prerequisites

1. A React Native project
2. **npm/yarn** are pre-installed
3. Xcode for iOS and Android Studio for Android are pre-installed
4. **homebrew** is pre-installed



> 
> 🔔 Pre-installed means that Codemagic machines already have the software ready to use, so there is no need to install it manually.
> 



## Preparing the application

Adjust your project's **package.json** file with Detox before starting Codemagic configurations:


```yaml

  "detox": {
    "runnerConfig": "e2e/config.json",
    "configurations": {
      "ios.sim.release": {
        "type": "ios.simulator",
        "device": {
          "type": "iPhone 14"
        },
        "binaryPath": "ios/build/Build/Products/Debug-iphonesimulator/MyReactNativeApp.app",
        "build": "xcodebuild -workspace ios/YOUR_APP.xcworkspace -scheme YOUR_APP -configuration Debug -sdk iphonesimulator -derivedDataPath ios/build"

      },
    }
  }

```


More information about Detox environment setup can be found in the official documentation [here](https://wix.github.io/Detox/docs/introduction/environment-setup).

## Running Detox tests in Codemagic

We are going to add all the scripts we need to run to install additional software and execute Detox tests to the `scripts` section of `codemagic.yaml`.

1. Install Detox CLI tools and **applesimutils** which is required by Detox to work with iOS simulators:
   

```yaml

npm install detox-cli --global
brew tap wix/brew
brew install applesimutils

```


2. Build and run Detox tests:
   

```yaml

detox build --configuration ios.sim.release
detox test --configuration ios.sim.release

```

 
Here is how your **codemagic.yaml** should look like:


```yaml

workflows:
  detox-test:
    name: Detox test automation
    environment:
      node: latest
      xcode: latest
    scripts:
      - name: Install Detox CLI tools
        script: npm install detox-cli --global
      - name: Install applesimutils
        script: |
          brew tap wix/brew
          brew install applesimutils
      - name: Build Detox app
        script: detox build --configuration ios.sim.release
      - name: Execute Detox testing
        script: detox test --configuration ios.sim.release

```


To run this workflow automatically in response to events in the repository, you can additionally configure [automatic build triggering](https://docs.codemagic.io/yaml-running-builds/starting-builds-automatically/).