babel-plugin-import-named-to-import-default

Modular import plugin for babel, compatible with material-ui, lodash, and so on.

Why babel-plugin-import-named-to-import-default

• English Instruction
• 中文说明

Where to add babel-plugin-import-named-to-import-default

• babelrc
• babel-loader

Example

{ "libraryName": "antd", "libraryDirectory": "lib" }

import { Button } from 'antd';
ReactDOM.render(<Button>xxxx</Button>);

      ↓ ↓ ↓ ↓ ↓ ↓

import Button from 'antd/lib/button';
ReactDOM.render(<Button>xxxx</Button>);

Note : with style: true css source files are imported and optimizations can be done during compilation time. With style: "css", pre bundled css files are imported as they are.

style: true can reduce the bundle size significantly, depending on your usage of the library.

Usage

npm install babel-plugin-import-named-to-import-default --save-dev

Via .babelrc or babel-loader.

{
  "plugins": [["import-multiple-to-import-default", options]]
}

options

options can be object.

{
  "libraryName": "antd"
}

{
  "libraryName": "lodash",
  "libraryDirectory": ""
}

{
  "libraryName": "@material-ui/core",
  "libraryDirectory": "components",  // default: lib
  "camel2DashComponentName": false,  // default: true
}

~options can be an array.~ It's not available in babel@7+

For Example:

[
  {
    "libraryName": "antd",
    "libraryDirectory": "lib",   // default: lib
    "style": true
  },
  {
    "libraryName": "antd-mobile"
  },
]

Options can't be an array in babel@7+, but you can add plugins with name to support multiple dependencies.

For Example:

// .babelrc
"plugins": [
  ["import", { "libraryName": "antd", "libraryDirectory": "lib"}, "antd"],
  ["import", { "libraryName": "antd-mobile", "libraryDirectory": "lib"}, "antd-mobile"]
]

style

• ["import", { "libraryName": "antd" }]: import js modularly
• ["import", { "libraryName": "antd", "style": true }]: import js and css modularly (LESS/Sass source files)
• ["import", { "libraryName": "antd", "style": "css" }]: import js and css modularly (css built files)

If option style is a Function, babel-plugin-import will auto import the file which filepath equal to the function return value. This is useful for the components library developers.

e.g.

• ["import", { "libraryName": "antd", "style": (name) => `${name}/style/2x` }]: import js and css modularly & css file path is ComponentName/style/2x

If a component has no style, you can use the style function to return a false and the style will be ignored.

e.g.

[
  "import",
    {
      "libraryName": "antd",
      "style": (name: string, file: Object) => {
        if(name === 'antd/lib/utils'){
          return false;
        }
        return `${name}/style/2x`;
      }
    }
]

styleLibraryDirectory

• ["import", { "libraryName": "element-ui", "styleLibraryDirectory": "lib/theme-chalk" }]: import js and css modularly

If styleLibraryDirectory is provided (default null), it will be used to form style file path, style will be ignored then. e.g.

{
  "libraryName": "element-ui",
  "styleLibraryDirectory": "lib/theme-chalk",
}

import { Button } from 'element-ui';

      ↓ ↓ ↓ ↓ ↓ ↓

var _button = require('element-ui/lib/button');
require('element-ui/lib/theme-chalk/button');

customName

We can use customName to customize import file path.

For example, the default behavior:

import { TimePicker } from "antd"
↓ ↓ ↓ ↓ ↓ ↓
var _button = require('antd/lib/time-picker');

You can set camel2DashComponentName to false to disable transfer from camel to dash:

import { TimePicker } from "antd"
↓ ↓ ↓ ↓ ↓ ↓
var _button = require('antd/lib/TimePicker');

And finally, you can use customName to customize each name parsing:

[
  "import",
    {
      "libraryName": "antd",
      "customName": (name: string, file: object) => {
        const filename = file.opts.filename;
        if (name === 'TimePicker'){
          return 'antd/lib/custom-time-picker';
        }
        if (filename.indexOf('/path/to/my/different.js') >= 0) {
          return 'antd/lib/custom-name';
        }
        return `antd/lib/${name}`;
      }
    }
]

So this result is:

import { TimePicker } from "antd"
↓ ↓ ↓ ↓ ↓ ↓
var _button = require('antd/lib/custom-time-picker');

In some cases, the transformer may serialize the configuration object. If we set the customName to a function, it will lost after the serialization.

So we also support specifying the customName with a JavaScript source file path:

[
  "import",
    {
      "libraryName": "antd",
      "customName": require('path').resolve(__dirname, './customName.js')
    }
]

The customName.js looks like this:

module.exports = function customName(name) {
  return `antd/lib/${name}`;
};

customStyleName

customStyleName works exactly the same as customName, except that it deals with style file path.

transformToDefaultImport

Set this option to false if your module does not have a default export.

Note

babel-plugin-import will not work properly if you add the library to the webpack config vendor.