Using import fs from 'fs'
JavascriptEs6 ModulesJavascript Problem Overview
I want to use import fs from 'fs'
in JavaScript. Here is a sample:
import fs from 'fs'
var output = fs.readFileSync('someData.txt')
console.log(output)
The error I get when I run my file using node main.js
is:
(function (exports, require, module, __filename, __dirname) { import fs from 'fs
'
^^^^^^
SyntaxError: Unexpected token import
What should I install in Node.js in order to achieve importing modules and functions from other places?
Javascript Solutions
Solution 1 - Javascript
For default exports you should use:
import * as fs from 'fs';
Or in case the module has named exports:
import {fs} from 'fs';
Example:
//module1.js
export function function1() {
console.log('f1')
}
export function function2() {
console.log('f2')
}
export default function1;
And then:
import defaultExport, { function1, function2 } from './module1'
defaultExport(); // This calls function1
function1();
function2();
Additionally, you should use Webpack or something similar to be able to use ES6 import
Solution 2 - Javascript
ES6 modules support in Node.js is fairly recent; even in the bleeding-edge versions, it is still experimental. With Node.js 10, you can start Node.js with the --experimental-modules
flag, and it will likely work.
To import on older Node.js versions - or standard Node.js 10 - use CommonJS syntax:
const fs = require('fs');
Solution 3 - Javascript
In order to use import { readFileSync } from 'fs'
, you have to:
- Be using Node.js 10 or later
- Use the
--experimental-modules
flag (in Node.js 10), e.g.node --experimental-modules server.mjs
(see #3 for explanation of .mjs) - Rename the file extension of your file with the
import
statements, to.mjs
, .js will not work, e.g. server.mjs
The other answers hit on 1 and 2, but 3 is also necessary. Also, note that this feature is considered extremely experimental at this point (1/10 stability) and not recommended for production, but I will still probably use it.
Here's the Node.js 10 ESM documentation.
Solution 4 - Javascript
Building on RobertoNovelo's answer:
import * as fs from 'fs';
is currently the simplest way to do it.
It was tested with a Node.js project (Node.js v10.15.3), with esm, allowing to use import
.
Solution 5 - Javascript
Go to package.json file and add:
"type": "module"
This worked for me!
Solution 6 - Javascript
The new ECMAScript module support is able natively in Node.js 12
It was released on 2019-04-23 and it means there is no need to use the flag --experimental-modules
.
To read more about it:
Solution 7 - Javascript
If we are using TypeScript, we can update the type definition file by running the command npm install @types/node
from the terminal or command prompt.
Solution 8 - Javascript
It's not supported just yet... If you want to use it you will have to install Babel.
Solution 9 - Javascript
hey friends node js use commonjs not modaljs so use alawys use const fs = require('fs') for file system if we use modaljs import fs from 'fs' its give error se in termile import {fs} from 'fs'; ^^^^^^ SyntaxError: Cannot use import statement outside a module