@nightwatch/react

Official Nightwatch plugin which adds component testing support for React apps. It uses the Vite dev server under the hood and vite-plugin-nightwatch. Requires Nightwatch 2.4+

npm install @nightwatch/react

Usage:

Update your Nightwatch configuration and add the plugin to the list:

module.exports = {
  plugins: ['@nightwatch/react']
  
  // other nightwatch settings...
}

Already using Vite in your project?

If you already have a Vite project, then the @nightwatch/react plugin will try to use the existing vite.config.js or vite.config.ts, if either one is found.

Check the vite-plugin-nightwatch project for more configuration options.

Update the vite.config.js and add the vite-plugin-nightwatch plugin:

// vite.config.js

import nightwatchPlugin from 'vite-plugin-nightwatch'

export default {
  plugins: [
    // ... other plugins, such as vue() or react()
    nightwatchPlugin()
  ]
})

Configuration

We’ve designed the @nightwatch/react plugin to work with sensible configuration defaults, but in some more advanced scenarios you may need to change some of the config options.

Vite dev server

By default, Nightwatch will attempt to start the Vite dev server automatically. You can disable that by adding the below in your nightwatch.conf.js file, under the vite_dev_server dictionary.

This is common to other component testing plugins that are based on Vite, such as the @nightwatch/vue plugin.

// nightwatch.conf.js

module.exports = {
  plugins: ['@nightwatch/react'],
  vite_dev_server: {
    start_vite: true,
    port: 5173
  }
}

Plugin options

The plugin accepts a few config options which can be set when working with an existing vite.config.js file in the project.

- `renderPage`

Specify the path to a custom test renderer to be used. A default renderer is included in the package, but this option can overwrite that value.

// vite.config.js

export default {
  plugins: [
    // ... other plugins, such as vue() or react()
    nightwatchPlugin({
      renderPage: './src/test_renderer.html'
    })
  ]
}

API Commands:

This plugin includes a few Nightwatch commands which can be used while writing React component tests.

- browser.mountComponent(`componentPath`, `[props]`, `[callback]`):

Parameters:

componentPath – location of the component file (.jsx) to be mounted
props – properties to be passed to the React component, this will be serialized to JSON; an inline string can be also used
callback – an optional callback function which will be called with the component element

Example:

const component = await browser.mountComponent('/src/components/Form.jsx')

const component = await browser.mountComponent('/src/components/Form.jsx', {
  prop: 'value'
})

A function or a string can be used for passing props that cannot be serialized. If a function is passed, it will be sent as a toString() value.

const component = await browser.mountComponent('/src/components/UserInfo.jsx', function () {
  return {
    date: new Date(),
    text: 'I hope you enjoy reading Ulysses!',
    author: {
      name: 'Leopold Bloom',
      avatarUrl: 'https://upload.wikimedia.org/wikipedia/commons/5/52/Poldy.png'
    }
  }
});

- browser.launchComponentRenderer():

This will call browser.navigateTo('/test_renderer/') and open the browser. Needs to be used before the .importScript() command, if used.

You can also set launchUrl as a global at runtime and then the url to be used will be ${browser.globals.launchUrl}/test_renderer, which makes it possible to set the launch url dynamically.

- browser.importScript(`scriptPath`, `[options]`, `[callback]`):

Parameters:

scriptPath – location of the script file to inject into the page which will render the component; needs to be written in ESM format
options – this can include:
- scriptType: the type attribute to be set on the <script> tag (default is module)
- componentType: should be set to 'react'
callback – an optional callback function which will be called with the component element

Example:

const formComponent = await browser
  .launchComponentRenderer()
  .importScript('/test/lib/scriptToImport.js');

Example scriptToImport.js:

import React from 'react'
import ReactDOM from 'react-dom'
import Component from '/test/components/Form.jsx'

const element = React.createElement(Component, {});
ReactDOM.render(element, document.getElementById('app'));

// This will be used by Nightwatch to inspect properties of this component
window['@@component_element'] = element;

Debugging Component Tests

Debugging component tests in Nightwatch isn't as straightforward as debugging a regular Node.js application or service, since Nightwatch needs to inject the code to render to component into the browser.

However, since Nightwatch v2.4 we provide several ways to inspect and debug the mounted component using the browser devtools console. Refer to the guide page on our docs website for more details: https://nightwatchjs.org/guide/component-testing/debugging.html

Example:

npx nightwatch test/src/userInfoTest.js --devtools --debug

Run tests:

Tests for this project are written in Nightwatch so you can inspect them as examples, located in the [test/src] folder.

Run them with::

npm test

Example project

We've put together a basic To-do app written in React and built on top of Vite which can be used as a boilerplate. It can be found at nightwatchjs-community/todo-react.

License

MIT