Naughty Program Manipulator

    jest-puppeteer-react
    TypeScript icon, indicating that this package has built-in type declarations

    8.1.0 • Public • Published

    jest-puppeteer-react Build Status

    yarn add jest-puppeteer-react
    

    This lib combines jest-puppeteer with webpack and webpack-dev-server to render your React components so you don't have to setup a server and navigate to it. It also includes jest-image-snapshot which adds the toMatchImageSnapshot matcher to expect.

    Setup

    1. Use the preset in your jest configuration:

      {
        "preset": "jest-puppeteer-react"
      }
      

      Or require / include the needed scripts.

    2. Add a config file which contains a function to return a webpack config which is used to render:

      const webpack = require('webpack');
      const path = require('path');
      const buildDevWebpackConfig = require('./packages/core/dev/webpack/dev');
      
      module.exports = {
          generateWebpackConfig: function generateWebpackConfig(entryFiles, aliasObject) {
              const webpackConfig = buildDevWebpackConfig('test', {
                  root: __dirname,
                  app: 'x',
              }, {
                  template: path.join(__dirname, './packages/dev-test-lib/screenshot/index.ejs'),
              }, webpack);
      
              webpackConfig.entry = { test: entryFiles };
              webpackConfig.resolve.alias = aliasObject;
      
              return webpackConfig;
          },
          port: 1111,
      };
      

    Usage

    Then use the specified render in your tests:

    import React from 'react';
    import { render } from 'jest-puppeteer-react';
    import Button from '../Button';
    
    describe('Button', () => {
        test('should render a button', async () => {
            await render(
                <Button>Button</Button>,
                { viewport: { width: 100, height: 100 } }
            );
    
            const screenshot = await page.screenshot();
            expect(screenshot).toMatchImageSnapshot();
        });
    });
    

    Options

    The second argument of render takes some options to make things easier. You can also supply a default for this via the config.

    {
        timeout: 60000, // 60 seconds
        viewport: {
            width: 100,
            height: 100,
            deviceScaleFactor: 2 // Retina Resolution
        }
    }
    

    Viewport

    Automatically calls page.setViewport() for you. See puppeteer docs for options.

    Configuration

    You can put a jest-puppeteer-react.config.js file in your project root which gets automatically detected by jest-puppeteer-react.

    Example:

    const webpack = require('webpack');
    const path = require('path');
    const buildDevWebpackConfig = require('./packages/core/dev/webpack/dev');
    
    module.exports = {
        generateWebpackConfig: function generateWebpackConfig(entryFiles, aliasObject) {
            const webpackConfig = buildDevWebpackConfig('test', {
                root: __dirname,
                app: 'x',
            }, {
                template: path.join(__dirname, './packages/dev-test-lib/screenshot/index.ejs'),
            }, webpack);
    
            webpackConfig.entry = { test: entryFiles };
            webpackConfig.resolve.alias = aliasObject;
    
            return webpackConfig;
        },
        port: 1111,
        renderOptions: {
            viewport: { deviceScaleFactor: 2 },
            dumpConsole: false, // set to true to dump console.* from puppeteer
    
            // function calls before page.goto()
            before: async (page) => {
                // for example, disable cache
                await page.setCacheEnabled(false);
            },
    
            // function calls after page.goto()
            after: (page) => {},
        },
    };
    

    Configure Puppeteer

    You can put a jest-puppeteer.config.js file in your root to configure puppeteer. This is a feature of the jest-puppeteer lib. See their readme for documentation: jest-puppeteer.

    Configure ESLint

    If you want to use the page object directly (without using the return value of render), you can set it as a global for eslint. See jest-puppeteer for an example.

    Limitations

    To be able to render the components in the browser, the test cases are required via webpack and the structure functions such as describe and test are evaluated. However, special behavior implemented in jest may be missing. For example mocks and timers are not supported currently. Furthermore at the moment hooks are not supported aswell. But they could be implemented quite easily.

    Install

    npm i jest-puppeteer-react

    DownloadsWeekly Downloads

    52

    Version

    8.1.0

    License

    MIT

    Unpacked Size

    34 kB

    Total Files

    30

    Last publish

    Collaborators

    • ansgar
    • rosczja