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import React, { useState } from 'react'; ^^^^^^ SyntaxError: Cannot use import statement outside a module [duplicate]

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."
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",

Verify that you have the latest version of Node.js installed (or, at least 13.2.0+). Then do one of the following, as described in the documentation:
Option 1
In the nearest parent package.json file, add the top-level "type" field with a value of "module". This will ensure that all .js and .mjs files are interpreted as ES modules. You can interpret individual files as CommonJS by using the .cjs extension.
// package.json
{
"type": "module"
}
Option 2
Explicitly name files with the .mjs extension. All other files, such as .js will be interpreted as CommonJS, which is the default if type is not defined in package.json.

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.

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": { ...
},
...
}

According to the official documentation:
import statements are permitted only in ES modules. For similar functionality in CommonJS, see import().
To make Node.js treat your file as an ES module, you need to (Enabling):
add "type": "module" to package.json
add "--experimental-modules" flag to the Node.js call

I ran into the same issue and it's even worse: I needed both "import" and "require"
Some newer ES6 modules works only with import.
Some CommonJS works with require.
Here is what worked for me:
Turn your js file into .mjs as suggested in other answers
"require" is not defined with the 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.
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.js 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 information: 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.js can run it.
So, we'll add our first script, build, in file package.json.
"scripts": {
"build": "babel index.js -d dist"
}
Then we'll add our start script in file 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

I Tried with all the methods, but nothing worked.
I got one reference from GitHub.
To use TypeScript imports with Node.js, I installed the below packages.
1. npm i typescript --save-dev
2. npm i ts-node --save-dev
Won't require type: module in package.json
For example,
{
"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"
}
}

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

Node v14.16.0
For those who've tried .mjs and got:
Aviator#AW:/mnt/c/Users/Adrian/Desktop/Programming/nodejs_ex$ node just_js.mjs
file:///mnt/c/Users/Adrian/Desktop/Programming/nodejs_ex/just_js.mjs:3
import fetch from "node-fetch";
^^^^^
SyntaxError: Unexpected identifier
and who've tried import fetch from "node-fetch";
and who've tried const fetch = require('node-fetch');
Aviator#AW:/mnt/c/Users/Adrian/Desktop/Programming/nodejs_ex$ node just_js.js
(node:4899) Warning: To load an ES module, set "type": "module" in the package.json or use the .mjs extension.
(Use `node --trace-warnings ...` to show where the warning was created)
/mnt/c/Users/Adrian/Desktop/Programming/nodejs_ex/just_js.js:3
import fetch from "node-fetch";
^^^^^^
SyntaxError: Cannot use import statement outside a module
and who've tried "type": "module" to package.json, yet continue seeing the error,
{
"name": "test",
"version": "1.0.0",
"description": "to get fetch working",
"main": "just_js.js",
"type": "module",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"author": "",
"license": "MIT"
}
I was able to switch to axios without a problem.
import axios from 'axios'; <-- put at top of file.
Example:
axios.get('https://www.w3schools.com/xml/note.xml').then(resp => {
console.log(resp.data);
});

I found the 2020 update to the answer in this link helpful to answering this question as well as telling you WHY it does this:
Using Node.js require vs. ES6 import/export
Here's an excerpt:
"Update 2020
Since Node v12, support for ES modules is enabled by default, but it's still experimental at the time of writing this. Files including node modules must either end in .mjs or the nearest package.json file must contain "type": "module". The Node documentation has a ton more information, also about interop between CommonJS and ES modules."

I'm new to Node.js, and I got the same issue for the AWS Lambda function (using Node.js) while fixing it.
I found some of the differences between CommonJS and ES6 JavaScript:
ES6:
Add "type":"module" in the package.json file
Use "import" to use from lib.
Example: import jwt_decode from jwt-decode
Lambda handler method code should be define like this
"exports.handler = async (event) => { }"
CommonJS:
Don't add "type":"module" in the package.json file
Use "require" to use from lib.
Example: const jwt_decode = require("jwt-decode");
The lambda handler method code should be defines like this:
"export const handler = async (event) => { }"

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!

To use import, do one of the following.
Rename the .js file to .mjs
In package.json file, add {type:module}

If you are using ES6 JavaScript imports:
install cross-env
in package.json change "test": "jest" to "test": "cross-env NODE_OPTIONS=--experimental-vm-modules jest"
more in package.json, add these:
...,
"jest": {
"transform": {}
},
"type": "module"
Explanation:
cross-env allows to change environment variables without changing the npm command. Next, in file package.json you change your npm command to enable experimental ES6 support for Jest, and configure Jest to do it.

This error also comes when you run the command
node filename.ts
and not
node filename.js
Simply put, with the 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.

If you want to use BABEL, I have a simple solution for that!
Remember this is for nodejs example: like an expressJS server!
If you are going to use react or another framework, look in the babel documentation!
First, install (do not install unnecessary things that will only trash your project!)
npm install --save-dev #babel/core #babel/node
Just 2 WAO
then config your babel file in your repo!
file name:
babel.config.json
{
"presets": ["#babel/preset-env"]
}
if you don't want to use the babel file, use:
Run in your console, and script.js is your entry point!
npx babel-node --presets #babel/preset-env -- script.js
the full information is here; https://babeljs.io/docs/en/babel-node

I had this error in my NX workspace after upgrading manually. The following change in each jest.config.js fixed it:
transform: {
'^.+\\.(ts|js|html)$': 'jest-preset-angular',
},
to
transform: {
'^.+\\.(ts|mjs|js|html)$': 'jest-preset-angular',
},

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 add --presets '#babel/preset-env'.
For example,
babel-node --trace-deprecation --presets '#babel/preset-env' ./yourscript.js
Or
in babel.config.js
module.exports = {
presets: ['#babel/preset-env'],
};

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'

For people coming to this thread due to this error in Netlify functions even after adding "type": "module" in package.json file, update your netlify.toml to use 'esbuild'. Since esbuild supports ES6, it would work.
[functions]
node_bundler = "esbuild"
Reference:
https://docs.netlify.com/functions/build-with-javascript/#automated-dependency-bundling

The documentation is confusing. I use Node.js to perform some local task in my computer.
Let's suppose my old script was test.js. Within it, if I want to use
import something from "./mylocalECMAmodule";
it will throw an error like this:
(node:16012) Warning: To load an ES module, set "type": "module" in the package.json or use the .mjs extension.
SyntaxError: Cannot use import statement outside a module
...
This is not a module error, but a Node.js error. Forbid loading anything outside a 'module'.
To fix this, just rename your old script test.js into test.mjs.
That's all.

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

In case you're running nodemon for the Node.js version 12, use this command.
server.js is the "main" inside package.json file, replace it with the relevant file inside your package.json file:
nodemon --experimental-modules server.js

I recently had the issue. The fix which worked for me was to add this to file 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".

If you are using node, you should refer to this document. Just setup babel in your node app it will work and It worked for me.
npm install --save-dev #babel/cli #babel/core #babel/preset-env

When I used sequelize migrations with npx sequelize db:migrate, I got this error, so my solution for this was adding the line require('#babel/register'); into the .sequelizerc file as the following image shows:
Be aware you must install Babel and Babel register.

Wrong MIME-Type for JavaScript Module Files
The common source of the problem is the MIME-type for "Module" type JavaScript files is not recognized as a "module" type by the server, the client, or the ECMAScript engine that process or deliver these files.
The problem is the developers of Module JavaScript files incorrectly associated Modules with a new ".mjs" (.js) extension, but then assigned it a MIME-type server type of "text/javascript". This means both .js and .mjs types are the same. In fact the new type for .js JavaScript files has also changed to "application/javascript", further confusing the issue. So Module JavaScript files are not being recognized by any of these systems, regardless of Node.js or Babel file processing systems in development.
The main problem is this new "module" subtype of JavaScript is yet known to most servers or clients (modern HTML5 browsers). In other words, they have no way to know what a Module file type truly is apart from a JavaScript type!
So, you get the response you posted, where the JavaScript engine is saying it needs to know if the file is a Module type of JavaScript file.
The only solution, for server or client, is to change your server or browser to deliver a new Mime-type that trigger ES6 support of Module files, which have an .mjs extension. Right now, the only way to do that is to either create a HTTP content-type on the server of "module" for any file with a .mjs extension and change your file extension on module JavaScript files to ".mjs", or have an HTML script tag with type="module" added to any external <script> element you use that downloads your external .js JavaScript module file.
Once you fool the browser or JavaScript engines into accepting the new Module file type, they will start doing their scripting circus tricks in the JS engines or Node.js systems you use.

NodeJS: SyntaxError: Unexpected token 'export' when trying to create a node module package

Firstly, I am very to the world or Node.js etc so apologies if this is an obvious problem.
I am creating a custom packages with a few components:
One component for example is this?
class MailProcess {
constructor(name, code) {
this.name = name;
this.code = code;
}
}
module.exports = {MailProcess: MailProcess};
and in my index file:
export {MailProcess} from "./mail/MailProcess";
// export more components like above
and my json file:
{
"name": "packagename",
"version": "1.0.3",
"description": "Private package",
"main": "index.js",
"publishConfig": {
"registry": "https://npm.pkg.github.com/...."
},
"scripts": {
"start": "node index.js"
},
"keywords": [],
"author": "",
"license": "ISC",
"dependencies": {
"aws-sdk": "^2.1172.0",
"mysql": "^2.18.1"
}
}
and in my Main code I (after installing the above package) I implement like this:
let {MailProcess} = require('#myusername/mypackagename');
but the error get thrown of
SyntaxError: Unexpected token 'export' relating to the index file.
I am wondering what I might be doing wrong. Essentially my pack contains a few different classes and I try to export them in index so the code using this package has access
Thanks for any help

Ok so I had this same issue, albeit with a different setup and I stumbled upon this question. At this point it may not be needed anymore, but I wanted to share what solved the problem in my case, in case it may help somebody else down the line.
My setup was basically a NodeJs (v16) project acting as a server, a frontend (not relevant to the problem) and the shared Types package.
My issue was that while everything worked fine when using npm link, it would not when publishing the Types package and installing it. Needless to say that the error was the same one:
export * from "./blocks";
^^^^^^
SyntaxError: Unexpected token 'export'
More specifically, in the top level index.ts of the Types package, which was "exporting everything out".
To give an idea, this was the relevant part of my package.json for my Types package:
"name": "vnotes-types",
"version": "1.1.3",
"description": "types for the VNotes application",
"main": "./src/index.ts",
"scripts": {
"compile": "tsc"
},
Moreover, on tsc I was compiling everything to a ./lib folder.
And the solution, basically, was:
Changing "main": "./src/index.ts" to "main": "./lib/index.js",. Here the problem was that I would employ the non-compiled index.ts (/src/index.ts) and import everything from there.
Adding "types": "./lib/index.d.ts". Basically points out to the type declarations.
I think this one isn't 100% necessary, but it reduces the size and clutter of the package: "files": ["./lib"] will only bundle the /lib folder, so your /src folder won't be included in the installation.
Hope this one helps people avoid wasting a stupid amount of time like I did to solve this issue.

Can't resolve module after npm-link for shared component repository

It is my first time trying npm-link, trying to create a shared component repository, and have hit an issue. I think I have linked the projecteds correctly as this message is displayed:
/Users/tom.allen/Development/main/project/node_modules/#linked/project -> /usr/local/lib/node_modules/#linked/project -> /Users/tom.allen/Development/shared_component_lib
The module is showing fine the the node_modules folder, however, when I try to add the component I created in the #linked/test repository I get an error saying:
Module not found: Error: Can't resolve '#linked/project' in '/Users/tom.allen/Development/...'
In the package.json for shared_component_lib i have:
"name": "#linked/project",
"version": "0.1.0",
"main": "index.js",
"dependencies": {
...
},
I am exporting the component as:
export { default as Hello } from './Hello';
and importing as:
import {Hello } from '#linked/project';
I have triple checked for spelling mistakes and had a look over the webpack config (which is far from a strong point for me) but can't really see where i've gone wrong.
Apologies in advance if this doesn't make much sense! Any help will be massively appreciated.

You should edit the package.json in shared_component_lib from "main": "index.js" to the actual location of file
ex:- "main" : "lib/index.js" or "main": "src/index.js"

Why can't a peerDependency be imported or required, even when it's present in the parent module?

I'm trying to use npm peerDependencies but nothing seems to work as advertised. What am I missing?
The setup is, I have two modules, mod and plugin, both of which depend on an external module from npm. mod declares a hard dependency on both plugin and the external module, and the plugin declares a peer dependency, in order to get access to the version being used by the parent module.
The files look like this:
~/plugin/package.json:
{
"name": "plugin",
"version": "1.0.0",
"main": "index.js",
"peerDependencies": {
"pad-right": "^0.2.2"
}
}
~/plugin/index.js
var peerDependency = require('pad-right')
module.exports = 'this is a plugin'
~/mod/package.json:
{
"name": "mod",
"version": "1.0.0",
"main": "index.js",
"dependencies": {
"pad-right": "^0.2.2",
"plugin": "../plugin"
}
}
~/mod/index.js:
var hardDependency = require('pad-right')
var plugin = require('plugin')
As I understand it from docs and examples, I think this should be a standard way to use peer dependencies, and running npm install in either directory doesn't give any errors or warnings.
However when I run webpack in the mod folder, I get errors like:
ERROR in ../plugin/index.js
Module not found: Error: Can't resolve 'pad-right' in '~/plugin'
# ../plugin/index.js 1:21-41
# ./index.js
What's going wrong here, shouldn't webpack resolve the require statement inside plugin with the peer dependency from the parent mod module?

Gah, it looks like this is an edge case that only affects modules that are referencing each other locally via the file system.
The solution is apparently to add something like:
resolve: {
alias: {
'pad-right': path.resolve('node_modules', 'pad-right'),
},
},
to your webpack config. (Or else to try resolve.symlinks: false, which solves the problem in the minimal repro code I posted, but doesn't solve things in my actual project).
Article about the issue

Error using prettyjson with Typescript

I'm trying to use https://www.npmjs.com/package/prettyjson with Typescript but it can't find the module.
I started with package.json:
{
"name": "prettyjson-test",
"description": "prettyjson with typescript",
"private": true,
"version": "0.0.1",
"engines": {
"node": "5.2.x",
"npm": "3.3.x"
}
}
Then I ran npm install prettyjson --save
Next I ran tsd install prettyjson --save
I created pj.ts:
/// <reference path="./typings/tsd.d.ts"/>
import prettyjson = require('prettyjson');
Finally, I ran tsc pj.ts --module "commonjs"
C:\projects\pj\pj.ts(3,1): error TS2071: Unable to resolve external module ''prettyjson''.
C:\projects\pj\pj.ts(3,1): error TS2072: Module cannot be aliased to a non-module type.
Based on TypeScript won't resolve external module (node.js), I'm guessing that the d.ts file is incorrect, but I'm not sure where to go next.

Seems like an error in the .d.ts indeed. Looks like they forgot to put quotes ("") around the module name:
Changing declare module prettyjson { to declare module "prettyjson" { in the .d.ts solved it for me. Next step would probably be a pull request or a notification to the guys that wrote it.