customize-cra

What is customize-cra?

The customize-cra package is a utility for customizing Create React App (CRA) configurations without ejecting. It allows you to override the default Webpack configuration, Babel configuration, and other settings in a CRA project.

What are customize-cra's main functionalities?

Override Webpack Configuration

This feature allows you to override the default Webpack configuration. In this example, a Webpack alias is added to simplify imports from the 'src/components' directory.

const { override, addWebpackAlias } = require('customize-cra');
const path = require('path');

module.exports = override(
  addWebpackAlias({
    ['@components']: path.resolve(__dirname, 'src/components')
  })
);

Modify Babel Configuration

This feature allows you to modify the Babel configuration. In this example, the 'babel-plugin-styled-components' plugin is added to the Babel configuration.

const { override, addBabelPlugin } = require('customize-cra');

module.exports = override(
  addBabelPlugin('babel-plugin-styled-components')
);

Add PostCSS Plugins

This feature allows you to add PostCSS plugins to the configuration. In this example, the 'postcss-preset-env' plugin is added.

const { override, addPostcssPlugins } = require('customize-cra');

module.exports = override(
  addPostcssPlugins([require('postcss-preset-env')])
);

Other packages similar to customize-cra

react-app-rewired

react-app-rewired is a package that allows you to override Create React App configurations without ejecting. It is similar to customize-cra but provides a more general approach to modifying CRA configurations. While customize-cra provides specific functions for common modifications, react-app-rewired allows for more manual and flexible configuration changes.

craco

CRACO (Create React App Configuration Override) is another package that allows you to customize Create React App configurations without ejecting. It is similar to customize-cra but offers a more structured and extensible way to modify CRA configurations. CRACO supports plugins and provides a more organized way to manage configuration changes.

README

customize-cra

This project provides a set of utilities to customize the Create React App v2 configurations leveraging react-app-rewired core functionalities.

How to install

⚠️ make sure you have react-app-rewired installed. You need to use this project with react-app-rewired; be sure to read their docs if you never have. The code in this project, documented below, is designed to work inside of react-app-rewired's config-overrides.js file.

npm

npm install customize-cra --save-dev

yarn

yarn add customize-cra --dev

Warning

"Stuff can break" - Dan Abramov

Using this library will override default behavior and configuration of create-react-app, and therefore invalidate the guarantees that come with it. Use with discretion!

Overview

To start, this project will export methods I need for what I'm using CRA for, but PRs will of course be welcome.

The functions documented below can be imported by name, and used in your config-overrides.js file, as explained below.

Available plugins

addBabelPlugin(plugin)

Adds a babel plugin. Whatever you pass for plugin will be added to Babel's plugins array. Consult their docs for more info. Note that this rewirer will not add the plugin to the yarn test's Babel configuration. See useBabelRc() to learn more.

addBabelPlugins(plugins)

A simple helper that calls addBabelPlugin for each plugin you pass in here. Make sure you use the spread operator when using this, for example

module.exports = override(
  disableEsLint(),
  ...addBabelPlugins(
    "polished",
    "emotion",
    "babel-plugin-transform-do-expressions"
  ),
  fixBabelImports("lodash", {
    libraryDirectory: "",
    camel2DashComponentName: false
  }),
  fixBabelImports("react-feather", {
    libraryName: "react-feather",
    libraryDirectory: "dist/icons"
  })
);

addBabelPresets(preset)

Adds a babel plugin. Whatever you pass for preset will be added to Babel's preset array. Consult their docs for more info. Note that this rewirer will not add the preset to the yarn test's Babel configuration. See useBabelRc() to learn more.

addBabelPresets(presets)

A simple helper that calls addBabelPreset for each preset you pass in here. Make sure you use the spread operator when using this, for example

module.exports = override(
  ...addBabelPresets([
    [
      "@babel/env",
      {
        targets: {
          browsers: ["> 1%", "last 2 versions"]
        },
        modules: "commonjs"
      }
    ],
    "@babel/preset-flow",
    "@babel/preset-react"
  ])
);

babelInclude

Overwrites the include option for babel loader, for when you need to transpile a module in your node_modules folder.

module.exports = override(
  babelInclude([
    path.resolve("src"), // make sure you link your own source
    path.resolve("node_modules/native-base-shoutem-theme"),
    path.resolve("node_modules/react-navigation"),
    path.resolve("node_modules/react-native-easy-grid")
  ])
);

fixBabelImports(libraryName, options)

Adds the babel-plugin-import plugin. See above for an example.

addDecoratorsLegacy()

Add decorators in legacy mode. Be sure to have @babel/plugin-proposal-decorators installed.

useBabelRc()

Use a .babelrc file for Babel configuration.

disableEsLint()

Does what it says. You may need this along with addDecoratorsLegacy in order to get decorators and exports to parse together.

If you want use @babel/plugin-proposal-decorators with EsLint, you can enable useEslintRc, described below, with the follow configuration in your .eslintrc or package.json:

{
  "extends": "react-app",
  "parserOptions": {
    "ecmaFeatures": {
      "legacyDecorators": true
    }
  }
}

useEslintRc(configFile)

Causes your .eslintrc file to be used, rather than the config CRA ships with. configFile is an optional parameter that allows to specify the exact path to the ESLint configuration file.

enableEslintTypescript()

Updates Webpack eslint-loader to lint both .js(x) and .ts(x) files and show linting errors/warnings in console.

addWebpackAlias(alias)

Adds the provided alias info into webpack's alias section. Pass an object literal with as many entries as you'd like, and the whole object will be merged in.

addWebpackResolve(resolve)

Adds the provided resolve info into webpack's resolve section. Pass an object literal with as many entries as you'd like, and the whole object will be merged in.

addWebpackPlugin(plugin)

Adds the provided plugin info into webpack's plugin array. Pass a plugin defined with new webpack.DefinePlugin({...})

addWebpackExternals(deps)

Add external dependencies, useful when trying to offload libs to CDN.

For example you can offload react and react-dom by

addWebpackExternals({
  'react': 'React',
  'react-dom': 'ReactDom'
})

addBundleVisualizer(options, behindFlag = false)

Adds the bundle visualizer plugin to your webpack config. Be sure to have webpack-bundle-analyzer installed. By default, the options passed to the plugin will be:

{
  "analyzerMode": "static",
  "reportFilename": "report.html"
}

You can hide this plugin behind a command line flag (--analyze) by passing true as second argument.

addBundleVisualizer({}, true);

useBabelRc()

Causes your .babelrc (or .babelrc.js) file to be used, this is especially useful if you'd rather override the CRA babel configuration and make sure it is consumed both by yarn start and yarn test (along with yarn build).

// config-overrides.js
module.exports = override(
  useBabelRc()
);

// .babelrc
{
  "presets": ["babel-preset-react-app"],
  "plugins": ["emotion"]
}

{
  analyzerMode: "static",
  reportFilename: "report.html"
}

which can be overridden with the (optional) options argument.

adjustWorkbox(fn)

Adjusts Workbox configuration. Pass a function which will be called with the current Workbox configuration, in which you can mutate the config object as needed. See below for an example.

adjustWorkbox(wb =>
  Object.assign(wb, {
    skipWaiting: true,
    exclude: (wb.exclude || []).concat("index.html")
  })
);

addLessLoader(loaderOptions)

First, install less and less-loader packages:

yarn add less
yarn add --dev less-loader

or:

npm i less
npm i -D less-loader

After it's done, call addLessLoader in override like below:

const { addLessLoader } = require("customize-cra");

module.exports = override(addLessLoader(loaderOptions));

loaderOptions is optional. If you have Less specific options, you can pass to it. For example:

const { addLessLoader } = require("customize-cra");

module.exports = override(
  addLessLoader({
    strictMath: true,
    noIeCompat: true,
    localIdentName: '[local]--[hash:base64:5]' // if you use CSS Modules, and custom `localIdentName`, default is '[local]--[hash:base64:5]'.
  })
);

Check Less document for all available specific options you can use.

Once less-loader is enabled, you can import .less file in your project.

.module.less will use CSS Modules.

if you use TypeScript (npm init react-app my-app --typescript) with CSS Modules, you should edit react-app-env.d.ts.

declare module '*.module.less' {
  const classes: { [key: string]: string };
  export default classes;
}

disableChunk

Prevents the default static chunking, and forces the entire build into one file. See this thread for more info.

Using the plugins

To use these plugins, import the override function, and call it with whatever plugins you need. Each of these plugin invocations will return a new function, that override will call with the newly modified config object. Falsy values will be ignored though, so if you need to conditionally apply any of these plugins, you can do so like below.

For example

const {
  override,
  addDecoratorsLegacy,
  disableEsLint,
  addBundleVisualizer,
  addWebpackAlias,
  adjustWorkbox
} = require("customize-cra");
const path = require("path");

module.exports = override(
  addDecoratorsLegacy(),
  disableEsLint(),
  process.env.BUNDLE_VISUALIZE == 1 && addBundleVisualizer(),
  addWebpackAlias({
    ["ag-grid-react$"]: path.resolve(__dirname, "src/shared/agGridWrapper.js")
  }),
  adjustWorkbox(wb =>
    Object.assign(wb, {
      skipWaiting: true,
      exclude: (wb.exclude || []).concat("index.html")
    })
  )
);

removeModuleScopePlugin()

This will remove the CRA plugin that prevents to import modules from outside the src directory, useful if you use a different directory.

A common use case is if you are using CRA in a monorepo setup, where your packages are under packages/ rather than src/.

MobX Users

If you want CRA 2 to work with MobX, use the addDecoratorsLegacy and disableEsLint.

Override dev server configuration

To override the webpack dev server configuration, you can use the overrideDevServer utility:

const {
  override,
  disableEsLint,
  overrideDevServer,
  watchAll
} = require("customize-cra");

module.exports = {
  webpack: override(
    // usual webpack plugin
    disableEsLint()
  ),
  devServer: overrideDevServer(
    // dev server plugin
    watchAll()
  )
};

watchAll()

When applied, CRA will watch all the project's files, included node_modules. To use it, just apply it and run the dev server with yarn start --watch-all.

watchAll();

add post-css plugins

To add post-css plugins, you can use addPostcssPlugins.

const { override, addPostcssPlugins } = require("customize-cra");

module.exports = override(
  addPostcssPlugins([require("postcss-px2rem")({ remUnit: 37.5 })])
);

addTslintLoader(loaderOptions)

Need to install tslint-loader.

const {
  addTslintLoader
} = require("customize-cra");

module.exports = override(
  addTslintLoader(),
);