README.md

Babel Preset SVGR

SVGR is the most popular library for importing SVG images into React applications (~5.8M weekly downloads). It provides SVG Webpack loader, Node API, and CLI tool, but there was no way to use it with Babel (see gregberge/svgr#306, gregberge/svgr#252).

This preset allows to transform SVG files into React components with SVGR and Babel. It works with any Babel setup (Babel CLI, @babel/node, @babel/register, Webpack babel-loader). If you use Hot Module Reloading in React, SVGs handled by this preset are correctly reloaded when changed.

Content

• Setup
• Under the Hood
• Compatibility with Create React App

Setup

1. Install the preset

   npm install --save-dev @dr.pogodin/babel-preset-svgr

   Depending on your setup, you may need to use --save flag to save it as a regular dependency, rather than the development one.

2. Add the preset to your Babel config, e.g.

   {
     "presets": [
       "@babel/env",
       "@babel/react",
       "@dr.pogodin/babel-preset-svgr"
     ]
   }

3. Instruct Babel to transform SVG files.

   • If you use Webpack and babel-loader, add SVG rule inside Webpack config as:

     module.exports = {
       module: {
         rules: [{
           test: /\.(jsx?|svg)$/
           exclude: [/node_modules/],
           loader: 'babel-loader',
           options: {
             /* babel-loader options */
           }
         }]
       }
     }

     With such setup you don't need to use @svgr/webpack loader for SVG files, Babel will take care about everything.

   • If you use @babel/node, or @babel/register you need to add .svg into their extensions option. For @babel/node use the flag --extensions '.js','.jsx','.svg', for @babel/register use extensions: ['.js', '.jsx', '.svg'] array inside the options object.

   • If you use Babel CLI and specify individual file(s) to compile, it will work out of the box for SVGs. If you use it to compile entire directories you'll need a dedicated compilation pass for SVG files with the flags --extensions '.svg' --keep-file-extension. In this dedicated pass Babel will only compile SVG assets, and it will keep their extensions. In a separate pass you'll compile JS(X) files as usual. The dedicated pass is necessary, as Babel currently either replaces all output file extensions to .js, or keeps all original ones. In our case we need to keep .svg extensions only (corresponding feature request in the Babel repo).

Under the Hood

This preset wraps the standard Babel parser into a simple logic which checks for .svg extensions of input, and if met, it runs the input code through SVGR before passing it to the Babel parser. For other file types it passes the code directly into Babel parser.

If your project already depends on a customized Babel parser, you can provide its path via the parser option of this preset. It will require() and use your parser then.

You also can pass in custom SVGR options via svgr field.

BEWARE: According to SVGR recommendations, three plugins mentioned below (@svgr/plugin-svgo, @svgr/plugin-jsx, and @svgr/plugin-prettier) are used by default, if you specify no custom SVGR options. The first two of them are MUST TO HAVE for successful SVG to JSX transformation, thus if you configure custom plugins, don't foget to include these two explicitly.

Example of options usage:

{
  "presets": [
    "@babel/env",
    "@babel/react",
    ["@dr.pogodin/babel-preset-svgr", {
      "parser": "custom-babel-parser",
      "mimicCreateReactApp": true,
      "svgr": {
        "plugins": [
          "@svgr/plugin-svgo",
          "@svgr/plugin-jsx",
          "@svgr/plugin-prettier"
        ]
      }
    }]
  ]
}

Compatibility with Create React App

Create React App sets up webpack to transform SVG components in the following way:

• The React component itself is exported as ReactComponent named export.
• The original SVG path is exported as the default export.

Thus, users import SVG assets like:

import originalPath, { ReactComponent } from './asset.svg';

This preset mimics such behavior when mimicCreateReactApp option is set:

{
  "presets": [
    "@babel/env",
    "@babel/react",
    ["@dr.pogodin/babel-preset-svgr", {
      "mimicCreateReactApp": true
    }]
  ]
}

By default, originalPath will be equal to the absolute path of each asset. In some cases you may want in different, and to cover such cases an object with additional options can be passed to mimicCreateReactApp:

// .babelrc.js

module.exports = {
  presets: [
    '@babel/env',
    '@babel/react',
    ['@dr.pogodin/babel-preset-svgr', {
      mimicCreateReactApp: {
        pathsRelativeTo: __dirname,
        pathsTransform: (path) => `some/prefix/${path}`,
      },
    }],
  ],
};

• If pathsRelativeTo option is set, originalPath will be relative to its value. If pathsRelativeTo is relative, it is resolved from the current working directory.
• If pathsTransform options is set, it should be a function which takes one argument - the originalPath, and returns the path that should be output into the transformed SVG.

Of course, __dirname and functions can be used only inside JS variation of Babel config, thus the example above displays .babelrc.js file, which can be used instead of .babelrc starting from Babel@7.