load-esm

load-esm is a utility for dynamically importing pure ESM (ECMAScript Module) packages in CommonJS TypeScript projects. This is particularly useful when working with Node.js environments configured for CommonJS while needing to integrate ESM-only dependencies.

Installation

npm install load-esm

or

yarn add load-esm

Features

• Enables dynamic import of pure ESM modules in CommonJS-based projects.
• Compatible with TypeScript, offering proper type definitions.
• Simple and lightweight implementation.

Usage

Here’s an example demonstrating how to use load-esm to dynamically load an ESM module in a CommonJS project:

import * as path from 'path';
import { loadEsm } from 'load-esm';

/**
 * Import 'file-type' ES-Module in CommonJS Node.js module
 */
(async () => {
    try {
        // Dynamically import the ESM module
        const { fileTypeFromFile } = await loadEsm('file-type');

        // Use the imported function
        const type = await fileTypeFromFile('fixture.gif');
        console.log(type);
    } catch (error) {
        console.error('Error importing module:', error);
    }
})();

API

loadEsm<T = any>(name: string): Promise<T>

Dynamically imports an ESM module.

Parameters

• name (string): The name or path of the module to load.

Returns

• A Promise<T> that resolves to the imported module object.

Example

import { loadEsm } from 'load-esm';

(async () => {
  const module = await loadEsm('some-esm-module');
  console.log(module);
})();

How It Works

The utility leverages Node.js's import() function to dynamically load ESM modules. This allows CommonJS-based projects to interact with ESM dependencies without converting the entire project to ESM.

Compatibility

• Node.js: Requires Node.js 13.2.0 or later, as import() is only supported in these versions and beyond.
• TypeScript: Fully typed and compatible with TypeScript.

Why Use load-esm?

In mixed-module environments where your project is primarily CommonJS but relies on some ESM-only dependencies, load-esm serves as a seamless bridge, enabling interoperability without changing your project’s module system.

License

MIT