ReferenceError: require is not defined in ES module scope, you can use import instead gulp sass

work for me , only change in package.json file, this line:

"type":"module" to "type":"commonjs"

While many node libraries support both require and import, I do occasionally run into cases where one library I need to use doesn't support require and another doesn't support import.

You can use createRequire to define require within an ES6 module and use that to also import Common JS libraries. Following is a sample code how to use it.

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

import crypto from 'crypto'
const fs = require('fs')

This answer is lifted straight from the this page: https://dev.to/caspergeek/how-to-use-require-in-ecmascript-modules-1l42

Can you check the "type" part in the package.json file? If the type part is module, you will get this error. You have to make it Commonjs.

This error is occurring because you are using "require" in a module.js environment.

This can occur either because you are in a file ending with .mjs OR You have defined your package.json to use the module type. E.g: "type": "module".

To fix this:

Change your requires to imports

const myModule = require("someModule") // ❌ using require inside of module scope
import myModule from "someModule" // ✅

Change your module.exports to exports

module.exports = (...) // ❌ using module inside of module scope
export default (...) // ✅

Alternatively:

If you need to use require (I recommend just changing require/module.exports to import and export), simply change your file extension from .js or .mjs to .cjs. This indicates to compilers that you want the type of this file to use features such as module and require.

Not directly applicable to OP but for those who spent a lot of time searching for a solution and finding that setting or removing "type" from package.json wasn't working, here it what fixed this issue for me.

1. I tested out require by itself by executing the following in a separate file:

require('dotenv').config();

console.log(process.env);

1. Upon seeing no errors and all my environment variables print out, I realized there must be something in my original server.js that must be causing the issue. I commented out the entire file except for the require('dotenv').config(); line, running the file and uncommenting subsequent lines until server.js broke. I discovered that uncommenting the following code causes the error:

    try {
        const testConnection = await pool.connect()
            .then(() => {
                console.log('Connected to PostgreSQL database');
            })
            .catch(err => {
                console.error('Connection error', err.stack);
            });
        testConnection.release();
    } catch (err) {
        console.error('Connection Error', err.stack);
    }

The issue at hand was that for some reason you can't use await at the top level of your code. await must be inside an async function. Since the above code literally just tests the connection to the db and then immediately disconnects, I just wrapped it as follows (and everything is back to normal!):

(async () => {
    try {
        ...
    } catch (err) {
        ...
    }
})();

If you are using Typescript and Jest and running into this problem, the answer provided by @prototype will get you halfway there, but you'll then run into an issue where Jest doesn't allow you to use import.meta.

Having now spent an enormous amount of time trying to get both import and require to work in both production and testing, I have arrived at a solution that I want to make sure I share:

Wherever you want to import a legacy package, you need the following:

function legacyRequireImport(path){
    if (process.env.NODE_ENV === "test"){
        return require(path);
    }
    const _require = createRequire(import.meta.url);
    return _require(path);
}
const someModule = legacyRequireImport("some_module");

Note: the function must be defined in the same file as it is being used. If you export this function and import it whenever you need it, it won't work. The function also cannot be called require, because that is a reserved word in commonJS (what Jest uses).

Now, if you just run that then you will get the following Jest error:

- error TS1343: The 'import.meta' meta-property is only allowed when the '--module' option is 'es2020', 'es2022', 'esnext', 'system', 'node16', or 'nodenext'.
     const _require = createRequire(import.meta.url);

In order to fix that, you can install a package called ts-jest-mock-import-meta and add the following to your jest.config:

    "transform": {
        "^.+\\.(j|t)s?$": ["ts-jest",
            {
                useESM: false,
                diagnostics: {
                    ignoreCodes: [1343]
                },
                astTransformers: {
                    before: [ "node_modules/ts-jest-mock-import-meta"]
                }
            }
        ],
    }

(this assumes you are using ts-jest, which you probably are if you are using typescript and jest)

You also need to make sure that you do not have a preset set in your jest.config, or else this won't work.

I know this seems insane, and it truly is insane, but this was genuinely the best solution I could find. And it does work. Best of luck.

A very different way to look at this issue, and I was having issues because of that. I tried a lot of different things and combinations, but the problem was because of Node Engines mismatch.
I was using node 24 but the engine mentioned in package.json was 20 as given below.
But I was getting the same error of import & required, and nowhere I didn't see anywhere the engine mismatched.

"engines": {
    "node": "20"
  }

To use a different Node Version you need NVM or Node Version Manager.
I'm providing commands for Mac, you can easily fine for windows.

# Install nvm
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.0/install.sh | bash
# Load nvm into your shell session (add these to ~/.zshrc if not auto-added)
export NVM_DIR="$HOME/.nvm"
[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"
# Restart your terminal, then:
nvm install 20 #you can set what every version you want to use.
nvm use 20

This error occurs because require is a CommonJS module syntax, whereas import is an ES6 module syntax. to solve this, you should use import instead of require ; and in you json package the type must contain "type": "module" if you are using Node js

I attach a code fragment that compiles without errors

import { DynamoDBClient } from  '@aws-sdk/client-dynamodb';
import { S3Client } from  '@aws-sdk/client-s3';

export const handler = async (event) => {
  // TODO implement  
  const response = {
    statusCode: 200,
    body: JSON.stringify('Hello from Lambda!'),
  };
  return response;
};