[javascript] SyntaxError: Cannot use import statement outside a module

I've got an ApolloServer project that's giving me trouble, so I thought I might update it and ran into issues when using the latest Babel. My "index.js" is:

require('dotenv').config()
import {startServer} from './server'
startServer()

And when I run it I get the error

SyntaxError: Cannot use import statement outside a module

First I tried doing things to convince TPTB* that this was a module (with no success). So I changed the "import" to a "require" and this worked.

But now I have about two dozen "imports" in other files giving me the same error.

*I'm sure the root of my problem is that I'm not even sure what's complaining about the issue. I sort of assumed it was Babel 7 (since I'm coming from Babel 6 and I had to change the presets) but I'm not 100% sure.

Most of what I've found for solutions don't seem to apply to straight Node. Like this one here:

ES6 module Import giving "Uncaught SyntaxError: Unexpected identifier"

Says it was resolved by adding "type=module" but this would typically go in the HTML, of which I have none. I've also tried using my project's old presets:

"presets": ["es2015", "stage-2"],
"plugins": []

But that gets me another error: "Error: Plugin/Preset files are not allowed to export objects, only functions."

UPDATE: Here are the dependencies I started with:

"dependencies": {
"@babel/polyfill": "^7.6.0",
"apollo-link-error": "^1.1.12",
"apollo-link-http": "^1.5.16",
"apollo-server": "^2.9.6",
"babel-preset-es2015": "^6.24.1",

If anyone is running into this issue with Typescript, the key to solving it for me was changing

    "target": "esnext",
    "module": "esnext",

to

    "target": "esnext",
    "module": "commonjs",

In my tsconfig.json. I was under the impression "esnext" was the "best", but that was just a mistake.

According to the official doc (https://nodejs.org/api/esm.html#esm_code_import_code_statements):

import statements are permitted only in ES modules. For similar functionality in CommonJS, see import().

To make Node treat your file as a ES module you need to (https://nodejs.org/api/esm.html#esm_enabling):

• add "type": "module" to package.json
• add "--experimental-modules" flag to the node call

For those who were as confused as I was when reading the answers, in your package.json file, add "type": "module" in the upper level as show below:

{
  "name": "my-app",
  "version": "0.0.0",
  "type": "module",
  "scripts": { ...
  },
  ...
}

I ran into the same issue and it's even worse: I needed both "import" and "require"

1. Some newer ES6 modules works only with import.
2. Some CommonJS works with require.

Here is what worked for me:

1. Turn your js file into .mjs as suggested in other answers

2. "require" is not defined with ES6 module, so you can define it this way:

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

   Now 'require' can be used in the usual way.

3. Use import for ES6 modules and require for commonJS.

Some useful links: node.js's own documentation. difference between import and require. Mozilla has some nice documentation about import

I had the same issue and the following has fixed it (using node 12.13.1):

• Change .js files extension to .mjs
• Add --experimental-modules flag upon running your app.
• Optional: add "type": "module" in your package.json

more info: https://nodejs.org/api/esm.html

First we'll install @babel/cli, @babel/core and @babel/preset-env.

$ npm install --save-dev @babel/cli @babel/core @babel/preset-env

Then we'll create a .babelrc file for configuring babel.

$ touch .babelrc

This will host any options we might want to configure babel with.

{
  "presets": ["@babel/preset-env"]
}

With recent changes to babel, you will need to transpile your ES6 before node can run it.

So, we'll add our first script, build, in package.json.

"scripts": {
  "build": "babel index.js -d dist"
}

Then we'll add our start script in package.json.

"scripts": {
  "build": "babel index.js -d dist", // replace index.js with your filename
  "start": "npm run build && node dist/index.js"
}

Now let's start our server.

$ npm start

Tried with all the methods but nothing worked

I got one reference from git hub.

To use type script imports with nodejs, i installed below packages.

1. npm i typescript

2. npm i ts-node

Won't require type: module in package.json

E:g

{
  "name": "my-app",
  "version": "0.0.1",
  "description": "",
  "scripts": {
   
  },
  "dependencies": {
    "knex": "^0.16.3",
    "pg": "^7.9.0",
    "ts-node": "^8.1.0",
    "typescript": "^3.3.4000"
  }
}

This error also comes when you run the command

node filename.ts

and not

node filename.js

To simply put, with node command we will have to run the JavaScript file (filename.js) and not the TypeScript file unless we are using a package like ts-node

In my case. I think the problem is in the standard node executable. node target.ts

I replaced it with nodemon and surprisingly it worked!

The way using the standard executable (runner):

node target.ts

The way using the nodemon executable (runner):

nodemon target.ts

Do not forget to install nodemon with npm install nodemon ;P

NOTE: this works amazing for development. But, for runtime, you may execute node with the compiled js file!

I had this issue when I was running migration

Its es5 vs es6 issue

Here is how I solved it

I run

npm install @babel/register

and add

require("@babel/register")

at the top of my .sequelizerc file my

and go ahead to run my sequelize migrate. This is applicable to other things apart from sequelize

babel does the transpiling

Just I want to add something to make your import work and avoid other issues like modules not working in node js. Just note that

With ES6 modules you can not yet import directories. Your import should look like this:

import fs from './../node_modules/file-system/file-system.js'

In Case your running nodemon for the node version 12 ,use this command. server.js is the "main" inside package.json file ,replace it with relevant file inside your package.json file

nodemon --experimental-modules server.js

Recently have the issue. The fix which work for me was to added this to babel.config.json in the plugins section

["@babel/plugin-transform-modules-commonjs", {
    "allowTopLevelThis": true,
    "loose": true,
    "lazy": true
  }],

I had some imported module with // and the error "cannot use import outside a module".

in the package.json write { "type": "module" }

it fixed my problem, I had the same problem

Step 1

yarn add esm

or

npm i esm --save

Step 2

package.json

  "scripts": {
    "start": "node -r esm src/index.js",
  }

Step 3

nodemon --exec npm start

just add --presets '@babel/preset-env'

e.g.

babel-node --trace-deprecation --presets '@babel/preset-env' ./yourscript.js

OR

in babel.config.js

module.exports = {
  presets: ['@babel/preset-env'],
};

1. I had the same problem when I started to used babel... But later, I had a solution... I haven't had the problem anymore so far... Currently, Node v12.14.1, "@babel/node": "^7.8.4", I use babel-node and nodemon to execute (node is fine as well..)
2. package.json: "start": "nodemon --exec babel-node server.js "debug": "babel-node debug server.js" !!note: server.js is my entry file, you can use yours.
3. launch.json When you debug, you also need to config your launch.json file "runtimeExecutable": "${workspaceRoot}/node_modules/.bin/babel-node" !!note: plus runtimeExecutable into the configuration.
4. Of course, with babel-node, you also normally need and edit another file, such as babel.config.js/.babelrc file

My solution was to include babel-node path while running nodemon as follows:

nodemon node_modules/.bin/babel-node index.js

you can add in your package.json script as :

debug: nodemon node_modules/.bin/babel-node index.js

NOTE: My entry file is index.js replace it with your entry file (many have app.js/server.js).

I had this problem in a fledgling Express API project.

The offending server code in src/server/server.js:

import express from 'express';
import {initialDonationItems, initialExpenditureItems} from "./DemoData";

const server = express();

server.get('/api/expenditures', (req, res) => {
  res.type('json');
  res.send(initialExpenditureItems);
});

server.get('/api/donations', (req, res) => {
  res.type('json');
  res.send(initialDonationItems);
});

server.listen(4242, () => console.log('Server is running...'));

Here were my dependencies:

{
  "name": "contributor-api",
  "version": "0.0.1",
  "description": "A Node backend to provide storage services",
  "scripts": {
    "dev-server": "nodemon --exec babel-node src/server/server.js --ignore dist/",
    "test": "jest tests"
  },
  "license": "ISC",
  "dependencies": {
    "@babel/core": "^7.9.6",
    "@babel/node": "^7.8.7",
    "babel-loader": "^8.1.0",
    "express": "^4.17.1",
    "mysql2": "^2.1.0",
    "sequelize": "^5.21.7",
    "sequelize-cli": "^5.5.1"
  },
  "devDependencies": {
    "jest": "^25.5.4",
    "nodemon": "^2.0.3"
  }
}

And here was the runner that threw the error:

nodemon --exec babel-node src/server/server.js --ignore dist

This was frustrating, as I had a similar Express project that worked fine.

The solution was firstly to add this dependency:

npm install @babel/preset-env

And then to wire it in using a babel.config.js in the project root:

module.exports = {
  presets: ['@babel/preset-env'],
};

I don't fully grok why this works, but I copied it from an authoritative source, so I am happy to stick with it.

simple just change it to : const uuidv1 = require('uuid'); it will work fine.