NodeJS and NPM module

With rollup.js, we can run CommonJS (CJS) and NodeJS (NPM) modules in WasmEdge too. The simple_common_js_demo/npm_main.js demo shows how it works. It utilizes the third-party md5 and mathjs modules.

const md5 = require('md5');
console.log('md5(message)=', md5('message'));

const {sqrt} = require('mathjs');
console.log('sqrt(-4)=', sqrt(-4).toString());

In order to run it, we must first use the rollup.js tool to build all dependencies into a single file. In the process, rollup.js converts CommonJS modules into WasmEdge-compatible ES6 modules. The build script is rollup.config.js.

const {babel} = require('@rollup/plugin-babel');
const nodeResolve = require('@rollup/plugin-node-resolve');
const commonjs = require('@rollup/plugin-commonjs');
const replace = require('@rollup/plugin-replace');

const globals = require('rollup-plugin-node-globals');
const builtins = require('rollup-plugin-node-builtins');
const plugin_async = require('rollup-plugin-async');

const babelOptions = {
  'presets': ['@babel/preset-react']

module.exports = [
    input: './npm_main.js',
    output: {
      inlineDynamicImports: true,
      file: 'dist/npm_main.mjs',
      format: 'esm',
    external: ['process', 'wasi_net','std'],
    plugins: [
      commonjs({ignoreDynamicRequires: false}),
        'process.env.NODE_ENV': JSON.stringify('production'),
        'process.env.NODE_DEBUG': JSON.stringify(''),

The package.json file specifies the rollup.js dependencies and the command to build the npm_main.js demo program into a single bundle.

  "dependencies": {
    "mathjs": "^9.5.1",
    "md5": "^2.3.0"
  "devDependencies": {
    "@babel/core": "^7.16.5",
    "@babel/preset-env": "^7.16.5",
    "@babel/preset-react": "^7.16.5",
    "@rollup/plugin-babel": "^5.3.0",
    "@rollup/plugin-commonjs": "^21.0.1",
    "@rollup/plugin-node-resolve": "^7.1.3",
    "@rollup/plugin-replace": "^3.0.0",
    "rollup": "^2.60.1",
    "rollup-plugin-babel": "^4.4.0",
    "rollup-plugin-node-builtins": "^2.1.2",
    "rollup-plugin-node-globals": "^1.4.0",
    "rollup-plugin-async": "^1.2.0"
  "scripts": {
    "build": "rollup -c rollup.config.js"

Run the following NPM commands to build npm_main.js demo program into dist/npm_main.mjs.

npm install
npm run build
cd ../../

Run the result JS file in WasmEdge CLI as follows.

$ wasmedge --dir .:. /path/to/wasmedge_quickjs.wasm example_js/simple_common_js_demo/dist/npm_main.mjs
md5(message)= 78e731027d8fd50ed642340b7c9a63b3
sqrt(-4)= 2i

You can import and run any NPM packages in WasmEdge this way.