React Native with Nx
Nx provides a holistic dev experience powered by an advanced CLI and editor plugins. It provides rich support for common tools like Detox, Storybook, Jest, and more.
In this guide we will show you how to develop React Native applications with Nx.
Creating Nx Workspace
The easiest way to create your workspace is via npx
.
npx create-nx-workspace happynrwl \
--preset=react-native \
--appName=mobile
Note: You can also run the command without arguments to go through the interactive prompts.
npx create-nx-workspace happynrwl
Once the command completes, the workspace will look as follows:
happynrwl/
βββ apps/
β βββ mobile/
β β βββ app.json
β β βββ metro.config.js
β β βββ android/
β β β βββ app/
β β β βββ gradle/
β β β βββ build.gradle
β β β βββ gradle.properties
β β β βββ gradlew
β β β βββ settings.gradle
β β βββ ios/
β β β βββ Mobile/
β β β βββ Mobile.xcodeproj/
β β β βββ Mobile.xcworkspace/
β β β βββ Podfile
β β β βββ Podfile.lock
β β βββ src/
β β β βββ main.tsx
β β β βββ app/
β β β βββ App.tsx
β β β βββ App.spec.tsx
β β βββ .babelrc
β β βββ jest.config.js
β β βββ test-setup.ts
β β βββ package.json
β β βββ project.json
β β βββ tsconfig.json
β β βββ tsconfig.app.json
β β βββ tsconfig.spec.json
β βββ mobile-e2e/
β βββ .detoxrc.json
β βββ src/
β β βββ app.spec.ts
β βββ .babelrc
β βββ jest.config.json
β βββ project.json
β βββ tsconfig.e2e.json
β βββ tsconfig.json
βββ libs/
βββ tools/
βββ babel.config.json
βββ jest.config.js
βββ jest.preset.js
βββ nx.json
βββ package-lock.json
βββ package.json
βββ tsconfig.base.json
βββ workspace.json
Run npx nx run-android mobile
to run the applicatoin in development mode on Android simulator/device. Run npx nx run-ios mobile
to run the applicatoin in developement mode on iOS simulator/device.
Try out other commands as well.
nx lint mobile
to lint the applicationnx test mobile
to run unit test on the application using Jestnx serve mobile
to serve the application Javascript bundler that communicates with connected devices. This will start the bundler at http://localhost:8081.nx sync-deps mobile
to sync app dependencies to itspackage.json
.
Release build
Android:
1npx nx build-android mobile
iOS: (Mac only)
No CLI support yet. Run in the Xcode project. See: https://reactnative.dev/docs/running-on-device
E2E
Android:
1npx nx test-android mobile-e2e
iOS: (Mac only)
1npx nx test-ios mobile-e2e
When using React Native in Nx, you get the out-of-the-box support for TypeScript, Detox, and Jest. No need to configure anything: watch mode, source maps, and typings just work.
Adding React Native to an Existing Workspace
For existing Nx workspaces, install the @nrwl/react-native
package to add React Native capabilities to it.
npm install @nrwl/react-native --save-dev
# Or with yarn
yarn add @nrwl/react-native --dev
Generating an Application
To create additional React Native apps run:
npx nx g @nrwl/react-native:app
Generating a Library
Nx allows you to create libraries with just one command. Some reasons you might want to create a library include:
- Share code between applications
- Publish a package to be used outside the monorepo
- Better visualize the architecture using
npx nx graph
For more information on Nx libraries, see our documentation on Creating Libraries and Library Types.
To generate a new library run:
npx nx g @nrwl/react-native:lib shared-ui-layout
And you will see the following:
happynrwl/
βββ apps/
β βββ mobile/
β βββ mobile-e2e/
βββ libs/
β βββ shared-ui-layout/
β βββ src/
β β βββ index.ts
β βββ .babelrc
β βββ jest.config.js
β βββ project.json
β βββ README.md
β βββ test-setup.ts
β βββ tsconfig.json
β βββ tsconfig.lib.json
β βββ tsconfig.spec.json
βββ tools/
βββ babel.config.json
βββ jest.config.js
βββ jest.preset.js
βββ nx.json
βββ package-lock.json
βββ package.json
βββ tsconfig.base.json
βββ workspace.json
Run:
npx nx test shared-ui-layout
to test the librarynpx nx lint shared-ui-layout
to lint the library
To generate a new comopnent inside shared-ui-layout
run:
npx nx g @nrwl/react-native:component layout --project=shared-ui-layout --export
And you will see the following updated for shared-ui-layout
:
happynrwl/
βββ libs/
βββ shared-ui-layout/
βββ src/
βββ index.ts
βββ lib/
βββ layout/
βββ layout.tsx
βββ layout.spec.tsx
Using Nx Library in your Application
You can import the shared-ui-layout
library in your application as follows.
1// apps/mobile/src/app/App.tsx
2import React from 'react';
3import { SafeAreaView } from 'react-native';
4
5import { Layout } from '@happynrwl/shared-ui-layout';
6
7const App = () => {
8 return (
9 <SafeAreaView>
10 <Layout />
11 </SafeAreaView>
12 );
13};
14
15export default App;
That's it! There is no need to build the library prior to using it. When you update your library, the React Native application will automatically pick up the changes.
Publishable libraries
For libraries intended to be built and published to a registry (e.g. npm) you can use the --publishable
and --importPath
options.
npx nx g @nrwl/react-native:lib shared-ui-layout --publishable --importPath=@happynrwl/ui-components
npx nx g @nrwl/react-native:component layout --project=shared-ui-layout --export
Run npx nx build shared-ui-layout
to build the library. It will generate the following:
dist/libs/shared-ui-layout/
βββ README.md
βββ index.d.ts
βββ lib/
β βββ layout/
β βββ layout.d.ts
βββ package.json
βββ shared-ui-layout.esm.css
βββ shared-ui-layout.esm.js
βββ shared-ui-layout.umd.css
βββ shared-ui-layout.umd.js
This dist folder is ready to be published to a registry.
Environment Variables
The workspace should installreact-native-config by default. To use environment variable, create a new .env
file in the happynrwl/apps/mobile
folder:
NX_BUILD_NUMBER=123
Then access variables defined there from your app:
1import Config from 'react-native-config';
2
3Config.NX_BUILD_NUMBER; // '123'
Code Sharing
Without Nx, creating a new shared library can take from several hours to even weeks: a new repo needs to be provisioned, CI needs to be set up, etc... In an Nx Workspace, it only takes minutes.
You can share React Native components between multiple React Native applications, share business logic code between React Native mobile applications and plain React web applications. You can even share code between the backend and the frontend. All of these can be done without any unnecessary ceremony.
Resources
Here are other resources that you may find useful to learn more about React Native and Nx.
- Blog post: Introducing React Native Support for Nx by Jack Hsu
- Blog post: Step by Step Guide on Creating a Monorepo for React Native Apps using Nx by Eimly Xiong