jest with ES6 modules

README.md

jest with ES6 modules

If you encounter this error when trying to use ES6 modules with jest:

SyntaxError: Cannot use import statement outside a module

Run the tests with:

NODE_OPTIONS=--experimental-vm-modules npx jest

And add this import to your *.test.js files: import { jest } from '@jest/globals'

index.js

export const hi = () => {
    console.log("hi")
}

index.test.js

import { jest } from '@jest/globals'
import { hi } from "."

it('should say hi', () => {
    console.log = jest.fn()
    hi()
    expect(console.log).toHaveBeenCalledWith("hi")
})

package.json

{
  "name": "es6_jest",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "start": "node index.js",
    "test": "NODE_OPTIONS=--experimental-vm-modules npx jest"
  },
  "keywords": ["es6", "jest"],
  "author": "github.com/ThePuscher",
  "license": "UNLICENSED",
  "type": "module",
  "devDependencies": {
    "jest": "^27.5.1"
  }
}