Using require() in ES Modules

The error occurs because you’re trying to use CommonJS require() syntax in a file that’s treated as an ES module (typically indicated by "type": "module" in your package.json or using .mjs extension).

Solutions

Option 1: Switch to ES Module imports (recommended)

// Change this:
const module = require('module-name');

// To this:
import module from 'module-name';
// or for named exports:
import { namedExport } from 'module-name';

Option 2: Convert your project to CommonJS

1. Remove "type": "module" from package.json (or set to "commonjs")
2. Change file extensions from .mjs to .cjs if needed

Option 3: Dynamic import (for async requires)

// Instead of:
const module = require('module-name');

// Use:
const module = await import('module-name');
// Then access default export with .default:
const thing = module.default;
// Or named exports:
const { namedThing } = module;

Option 4: Create compatibility layer (not recommended)

import { createRequire } from 'module';
const require = createRequire(import.meta.url);

// Now you can use require
const module = require('module-name');

Key Differences

Feature	ES Modules (import)	CommonJS (require)
Syntax	Static (analyzed at compile)	Dynamic (runtime)
Loading	Asynchronous	Synchronous
File extension	.mjs or type:module	.js/.cjs or default
Node support	v12+	All versions

Best Practice

• New projects should use ES Modules (import/export)
• If working with older code, either:
• Convert to ES Modules gradually
• Use .cjs extension for CommonJS files
• Use dynamic imports when needed

Example Conversion

Before (CommonJS):

const fs = require('fs');
const { readFile } = require('fs').promises;
module.exports = { myFunction };

After (ES Modules):

import fs from 'fs';
import { promises } from 'fs';
const { readFile } = promises;
export { myFunction };
// or export default myFunction;