@babel/plugin-transform-dynamic-import

info

This plugin is included in @babel/preset-env, in ES2020.

Transforms import() expressions to non-ESM module formats.

When (not) to use this plugin

If you are using a bundler, such as Webpack, Rollup or Parcel, you should not use this plugin and let your bundler handle import() expressions.

You should use this plugin if:

• You are authoring a Node.js library in ESM but want to distribute it in CommonJS(CJS): Install this plugin and @babel/plugin-transform-modules-commonjs
• You use RequireJS to load modules in the browser: Install this plugin and @babel/plugin-transform-modules-amd
• You use SystemJS to load modules in the browser: Install this plugin and @babel/plugin-transform-modules-systemjs

This plugin must be used with one of the module transform plugins mentioned above.

Example

input.js

import("jquery").then($ => {});

will be transformed to

• CommonJS
• AMD
• SystemJS

output.js

Promise.resolve()
  .then(() => _interopRequireWildcard(require("jquery")))
  .then(($) => {});

output.js

define(["require"], function (_require) {
  new Promise((_resolve, _reject) =>
    _require(
      ["jquery"],
      (imported) => _resolve(_interopRequireWildcard(imported)),
      _reject
    )
  ).then(($) => {});
});

output.js

System.register([], function (_export, _context) {
  "use strict";
  return {
    setters: [],
    execute: function () {
      _context.import("jquery").then(($) => {});
    }
  };
});

Installation

• npm
• Yarn
• pnpm

npm install --save-dev @babel/plugin-transform-dynamic-import

yarn add --dev @babel/plugin-transform-dynamic-import

pnpm add --save-dev @babel/plugin-transform-dynamic-import

Usage

With a configuration file (Recommended)

babel.config.json

{
  "plugins": [
    "@babel/plugin-transform-dynamic-import",
    "@babel/plugin-transform-modules-commonjs"
  ]
}

Via CLI

Shell

babel --plugins=@babel/plugin-transform-dynamic-import,@babel/plugin-transform-modules-amd script.js

Via Node API

JavaScript

require("@babel/core").transformSync("code", {
  plugins: [
    "@babel/plugin-transform-dynamic-import",
    "@babel/plugin-transform-modules-systemjs"
  ],
});

References

• Proposal: import()