Building and Testing

Our JavaScript code is thoroughly verified with comprehensive unit tests, complemented by integration tests. Additionally, our native code undergoes rigorous testing through both unit and integration tests. To ensure complete functionality, we conduct end-to-end tests on a fully-featured React Native application, designed to encompass all our public APIs (refer to our test app for details).

Important

Before submitting a pull request, please ensure at a minimum that your code adheres to our linting standards and that all unit tests run successfully without any errors.

The following sections describe how to build and test our code, with a general instruction. However, we recommend you to refer to our package.json files for a complete list of available scripts:

• Detox Framework: detox/package.json
• Detox Test App: detox/test/package.json

Unit Tests (JavaScript)

We use Jest for running our unit tests.

Under the detox/ directory, run the following command to run the unit tests with coverage:

cd detox
npm run unit

The unit tests reside alongside the JavaScript code. Typically, they can also be easily run directly from within an IDE such as WebStorm or vscode, even in debug (i.e step-by-step execution) mode.

Unit Tests - Android Native

We also have unit tests for our native code (Android only). They reside alongside Detox's native Android code, under a dedicated subdirectory called testFull. You can run them using the following commands:

cd detox
npm run unit:android-release

The native unit tests can also be run in Android Studio (i.e. the IDE for Android apps development). Most tests can be run seamlessly using Android Studio's build-in support for unit-tests, but some require a plugin called Spek, which can be installed from within Android Studio itself - under the Plugins marketplace.

iOS: Rebuilding the Native Code

Detox Framework

After changing the native code of Detox iOS, you need to rebuild the Detox framework. This is done when running:

detox build-framework-cache

Note that it is only required when you change the native code of Detox, or one of its dependencies (e.g. DetoxSync). If you are only changing the JavaScript code, you don't need to rebuild the framework.

Building the Detox Test App

The Detox self-test app is a full-feature React Native app for testing Detox end-to-end.

Before running the tests, you must first build the Detox test app. To do so, under detox/test, use the build command of the Detox CLI. List of available configurations can be found under detox/test/e2e/detox.config.js.

For example, to build the Detox test app for iOS in release mode, run:

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

End-to-End Tests

To run the end-to-end tests (after building the app), use the test command of the Detox CLI.

For example, to run the end-to-end tests for iOS in release mode, run:

cd detox/test
detox test --configuration ios.sim.release

note

Mind that on iOS, Detox expects a specific simulator device with a specific name and os version to be available in your Xcode environment. The required details are specified in the detox.config.js under ios.simulator device configuration (see type and os). Be sure to install such a device, beforehand.

To run in Android release mode, run:

cd detox/test
detox test --configuration android.emu.release

note

Mind that on Android, Detox expects a specific AVD with a specific name to be available on your computer. The required details are specified in the detox.config.js under android.emulator device configuration (see avdName). Be sure to install such an AVD, beforehand.

Integration Tests

Besides unit tests and end-to-end tests, we have some middle ground integration tests, which typically run Detox in a custom headless-like mode (i.e. stubs replace devices). Those tests typically execute Detox from a command line in that mode, and then do some post-processing of the results. We use Jest for running our integration tests.

The integration reside under a dedicated directory alongside Detox's the self-test app's code.

Run the following command to run the integration tests:

cd detox/test
npm run integration

Linting

We use ESLint for linting our JavaScript code.

You can run the linter locally using the following command (under detox/test):

npm run lint

We also test our types using the following command:

npm run test:types

Running the CI Scripts Locally

On our CI, we test our changes on both iOS and Android, and we lint-check our code. You can run the same scripts we run on our CI locally, to ensure your changes are passing the tests (under the project's root directory):

npm run ci:ios
npm run ci:android

Refer to the scripts scripts/ci.ios.sh and scripts/ci.android.sh to see how we run the tests on our CI.