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Customization

Options

As of Razzle 3.2, you can modify some parts of Razzle with options.

We show the default options here:

//./razzle.config.js
module.exports = {
  options: {
    verbose: false, // set to true to get more info/error output
    debug: { // debug flags
      options: false, // print webpackOptions that will be used in webpack config
      config: false, // print webpack config
      nodeExternals: false // print node externals debug info 
    },
    buildType: 'iso', // or 'spa', 'serveronly', 'iso-serverless' and 'serveronly-serverless'
    cssPrefix: 'static/css',
    jsPrefix: 'static/js',
    mediaPrefix: 'static/media',
    staticCssInDev: false, // static css in development build (incompatible with css hot reloading)
    browserslist: undefined, // or what your apps package.json says
    enableSourceMaps: true,
    enableReactRefresh: false,
    enableTargetBabelrc: false, // enable to use .babelrc.node and .babelrc.web
    enableBabelCache: true,
    forceRuntimeEnvVars: [], // force env vars to be read from env e.g. ['HOST', 'PORT']
    disableWebpackbar: false, // can be true to disable all environments or target to disable specific environment such as "node" or "web"
    staticExport: {
      parallel: 5, // how many pages to render at a time
      routesExport: 'routes',
      renderExport: 'render',
      scriptInline: false,
      windowRoutesVariable: 'RAZZLE_STATIC_ROUTES',
      windowRoutesDataVariable: 'RAZZLE_STATIC_DATA_ROUTES'
    },
  },
};

More options will be added in the future, some options now in experimental will be moved here.

Plugins

As of Razzle 2.0, you can add your plugins to modify your setup.

Using Plugins

You can use Razzle plugins by installing in your project and adding them to your razzle.config.js. See the README.md of the specific plugin, but generally speaking, the flow is something like...

yarn add razzle-plugin-xxxx
//./razzle.config.js
module.exports = {
  plugins: ['xxxx'],
};

Writing Plugins

Plugins are simply a collection of functions that modify and return Razzle/webpack/jest configuration.

There are five functions that can be used to hook into Razzle configuration.

  • modifyOptions - modifies default Razzle options and options passed to Razzle in the options key in razzle.config.js.
  • modifyPaths - modifies default Razzle paths.
  • modifyWebpackOptions - modifies some default options that will be used to configure webpack/ webpack loaders and plugins.
  • modifyWebpackConfig - modifies the created webpack config.
  • modifyJestConfig - modifies jest config that is used to run tests for yor app.

Here is a complete plugin that uses all five functions, usually you just need modifyWebpackConfig and/or modifyWebpackOptions.

'use strict';
module.exports = {
  modifyOptions({
    webpackObject, // the imported webpack node module
    options: {
      pluginOptions, // the options passed to the plugin ({ name:'pluginname', options: { key: 'value'}})
      razzleOptions, // the default options/ options passed to Razzle in the `options` key in `razzle.config.js` (options: { key: 'value'})
    },
  }) {
    // Do some stuff...
    return razzleOptions;
  },
  modifyPaths({
    webpackObject, // the imported webpack node module
    options: {
      pluginOptions, // the options passed to the plugin ({ name:'pluginname', options: { key: 'value'}})
      razzleOptions, // the modified options passed to Razzle in the `options` key in `razzle.config.js` (options: { key: 'value'})
    },
    paths, // the default paths that will be used by Razzle.
  }) {
    // Do some stuff...
    return paths;
  },
  modifyWebpackOptions({
    env: {
      target, // the target 'node' or 'web'
      dev, // is this a development build? true or false
    },
    webpackObject, // the imported webpack node module
    options: {
      pluginOptions, // the options passed to the plugin ({ name:'pluginname', options: { key: 'value'}})
      razzleOptions, // the modified options passed to Razzle in the `options` key in `razzle.config.js` (options: { key: 'value'})
      webpackOptions, // the default options that will be used to configure webpack/ webpack loaders and plugins
    },
    paths, // the modified paths that will be used by Razzle.
  }) {
    if (target === 'web') {
      // client only
    }
    if (target === 'node') {
      // server only
    }
    if (dev) {
      // dev only
    } else {
      // prod only
    }
    // Do some stuff...
    return webpackOptions;
  },
  modifyWebpackConfig({
    env: {
      target, // the target 'node' or 'web'
      dev, // is this a development build? true or false
    },
    webpackConfig, // the created webpack config
    webpackObject, // the imported webpack node module
    options: {
      pluginOptions, // the options passed to the plugin ({ name:'pluginname', options: { key: 'value'}})
      razzleOptions, // the modified options passed to Razzle in the `options` key in `razzle.config.js` (options: { key: 'value'})
      webpackOptions, // the modified options that was used to configure webpack/ webpack loaders and plugins
    },
    paths, // the modified paths that will be used by Razzle.
  }) {
    if (target === 'web') {
      // client only
    }
    if (target === 'node') {
      // server only
    }
    if (dev) {
      // dev only
    } else {
      // prod only
    }
    // Do some stuff...
    return webpackConfig;
  },
  modifyJestConfig({
    jestConfig, // the created jest config
    webpackObject, // the imported webpack node module
    options: {
      pluginOptions, // the options passed to the plugin ({ name:'pluginname', options: { key: 'value'}})
      razzleOptions, // the modified options passed to Razzle in the `options` key in `razzle.config.js` (options: { key: 'value'})
    },
    paths, // the modified paths that will be used by Razzle.
  }) {
    // Do some stuff...
    return jestConfig;
  },
};

Plugins also support using promises, this example uses modifyWebpackConfig but promises are supported in all hooks.

'use strict';
module.exports = {
  modifyWebpackConfig({
    env: { target, dev },
    webpackConfig,
    webpackObject,
    options: { pluginOptions, razzleOptions, webpackOptions },
    paths,
  }) {
    return new Promise(async resolve => {
      if (target === 'web') {
        // client only
      }
      if (target === 'node') {
        // server only
      }
      if (dev) {
        // dev only
        await getDevcert();
      } else {
        // prod only
      }
      // Do some stuff...
      resolve(webpackConfig);
    });
  },
};

Using scoped packages

Razzle supports plugins using scoped packages.

Name your plugin @scope-name/razzle-plugin-<name>

And reference it in your razzle.config.js as follows

//./razzle.config.js
module.exports = {
  plugins: ['@scope-name/name'],
};

Note that razzle-plugin- is omitted

Customizing Babel Config

Razzle includes the razzle/babel preset to your app, it includes everything needed to compile React applications and server-side code. But if you want to extend the default Babel configs, it's also possible.

To start, you only need to define a .babelrc file at the top of your app, if such file is found, we're going to consider it the source of truth, therefore it needs to define what Razzle needs as well, which is the razzle/babel preset.

Here's an example .babelrc file:

{
  "presets": ["razzle/babel"],
  "plugins": []
}

You can take a look at this file to learn about the presets included by razzle/babel.

To add presets/plugins without configuring them, you can do it this way:

{
  "presets": ["razzle/babel"],
  "plugins": ["@babel/plugin-proposal-do-expressions"]
}

To add presets/plugins with custom configuration, do it on the razzle/babel preset like so:

{
  "presets": [
    [
      "razzle/babel",
      {
        "preset-env": {},
        "transform-runtime": {},
        "class-properties": {}
      }
    ]
  ],
  "plugins": []
}

To learn more about the available options for each config, visit their documentation site.

Razzle uses the current Node.js version for server-side compilations.

The modules option on "preset-env" should be kept to false, otherwise webpack code splitting is turned off.

Extending Webpack

You can also extend the underlying webpack config. Create a file called razzle.config.js in your project's root.

All the hook functions supported in plugins is also supported here. We show only one function here for brevity.

In Razzle 3.3 modify was deprecated. In Razzle 4.0 it was replaced with modifyWebpackConfig.

// razzle.config.js
module.exports = {
  modifyWebpackConfig({
    env: {
      target, // the target 'node' or 'web'
      dev, // is this a development build? true or false
    },
    webpackConfig, // the created webpack config
    webpackObject, // the imported webpack node module
    options: {
      razzleOptions, // the modified options passed to Razzle in the `options` key in `razzle.config.js` (options: { key: 'value'})
      webpackOptions, // the modified options that will be used to configure webpack/ webpack loaders and plugins
    },
    paths, // the modified paths that will be used by Razzle.
  }) {
    if (target === 'web') {
      // client only
    }
    if (target === 'node') {
      // server only
    }
    if (dev) {
      // dev only
    } else {
      // prod only
    }
    // Do some stuff...
    return webpackConfig;
  },
};

A word of advice: razzle.config.js is an escape hatch. However, since it's just JavaScript, you can and should publish your modify* functions to npm to make it reusable across your projects. For example, imagine you added some custom webpack loaders and published it as a package to npm as my-razzle-modifications. You could then write your razzle.config.js like so:

// razzle.config.js
const modifications = require('my-razzle-modifictions');
module.exports = modifications;

Last but not least, if you find yourself needing a more customized setup, Razzle is very forkable. There is one webpack configuration factory that is 1000 lines of code, and 5 scripts (build, start, test, export and init). The paths setup is shamelessly taken from create-react-app, and the rest of the code related to logging.

New in razzle 3.2

razzle.config.js modify also support using promises

// razzle.config.js
module.exports = {
  modifyWebpackConfig({
    env: { target, dev },
    webpackConfig,
    webpackObject,
    options: { razzleOptions, webpackOptions },
    paths,
  }) {
    return new Promise(async resolve => {
      if (target === 'web') {
        // client only
      }
      if (target === 'node') {
        // server only
      }
      if (dev) {
        // dev only
        await getDevcert();
      } else {
        // prod only
      }
      // Do some stuff...
      resolve(webpackConfig);
    });
  },
};

CSS Modules

Razzle supports CSS Modules using Webpack's css-loader. Simply import your CSS file with the extension .module.css and Razzle will process the file using css-loader.

import React from 'react';
import styles from './style.module.css';
const Component = () => <div className={styles.className} />;
export default Component;

Polyfills

Polyfills for IE 9, IE 10, and IE 11 are no longer included by default (but you can opt in!) We have dropped default support for Internet Explorer 9, 10, and 11. If you still need to support these browsers, follow the instructions below.

First, install react-app-polyfill:

npm install react-app-polyfill or

yarn add react-app-polyfill Next, place one of the following lines at the very top of src/client.js:

import 'react-app-polyfill/ie9'; // For IE 9-11 support
import 'react-app-polyfill/ie11'; // For IE 11 support

Transpilation of external modules

If you need to transpile external modules with arrow functions etc.

Make sure the modules are not externalized and are added to the babelRule include.

// razzle.config.js
'use strict';
module.exports = {
  modifyWebpackOptions({
    env: {
      target, // the target 'node' or 'web'
      dev, // is this a development build? true or false
    },
    options: {
      webpackOptions, // the default options that will be used to configure webpack/ webpack loaders and plugins
    }
  }) {
    webpackOptions.notNodeExternalResMatch = (request, context) => {
       return /themodule|anothermodule/.test(request)
    };
    webpackOptions.babelRule.include = webpackOptions.babelRule.include.concat([
      /themodule/,
      /anothermodule/
    ]);
    return webpackOptions;
  }
};

Absolute Imports

You can configure your application to support importing modules using absolute paths. This can be done by configuring a jsconfig.json or tsconfig.json file in the root of your project. If you're using TypeScript in your project, you will already have a tsconfig.json file.

Below is an example jsconfig.json file for a JavaScript project (or tsconfig.json if you're using TypeScript). You can create the file if it doesn't already exist:

{
  "compilerOptions": {
    "baseUrl": "src"
  },
  "include": ["src"]
}

To make the Jest test runner work with absolute imports, you'll need to add a jest configuration option to your package.json:

{
  "name": "my-razzle-app",
  "version": "1.0.0",
  "license": "MIT",
  /* ...dependencies, etc... */
  "jest": {
    "moduleDirectories": ["node_modules", "src"]
  }
}

Now that you've configured your project to support absolute imports, if you want to import a module located at src/components/Button.js, you can import the module like so:

import Button from 'components/Button';

Aliased Paths/ Modules

You can configure your application to support importing modules using aliased paths. This can be done by configuring a jsconfig.json or tsconfig.json file in the root of your project. If you're using TypeScript in your project, you will already have a tsconfig.json file.

{
  "compilerOptions": {
    "baseUrl": "src",
    "paths": {
      "@extra/*": ["../extra/*"]
    }
  }
}

Now that you've configured your project to support aliased imports, if you want to import a module located at extra/components/Button.js, you can import the module like so:

import Button from '@extra/components/Button';

Experimental

Razzle has support for some experimental features. Coming soon.