Nextjs with Jest - unexpected token export

Question 1

I have a Next.js project with TypeScript.

It's a page router instead of an app router
No babel config file(.babelrc etc) in the project

The error occurs when I runnpm test.jost seems to be one of the packages used byauth0.

XXXX/node_modules/jose/dist/browser/index.js:1    export { compactDecrypt } from './jwe/compact/decrypt.js';    ^^^^^^    SyntaxError: Unexpected token 'export'

I tried the two solutions below, but I still received the same error.

jest.config.ts

import type { Config } from 'jest';import nextJest from 'next/jest.js';const createJestConfig = nextJest({  dir: './',});const config: Config = {  coverageProvider: 'v8',  testEnvironment: 'jsdom',  roots: ['<rootDir>/tests/unit'],  // Solution 1  transformIgnorePatterns: [     "/!node_modules\\/jose/"  ],  // Solution 2  moduleNameMapper: {    "^jose$": "jose"  }};export default createJestConfig(config);

package.json

{  ...,  "scripts": {    "test": "jest"  },  "dependencies": {    "next": "^15.2.5",    "react-dom": "^18.2.0",    "auth0": "^4.4.0",    ...  },  "devDependencies": {    "@testing-library/dom": "^10.4.1",    "@testing-library/jest-dom": "^6.8.0",    "@testing-library/react": "^16.3.0",    "@types/jest": "^30.0.0",    "@types/react": "^18.3.20",    "@types/react-dom": "^18.3.6",    "jest": "^30.1.3",    "jest-environment-jsdom": "^30.1.2",    "node-mocks-http": "^1.17.2",    "ts-jest": "^29.4.1",    "ts-node": "^10.9.2",    "typescript": "^5.8.3"  }}

api.test.ts

import handler from '@pages/api/users';import { createMocks, createRequest, createResponse } from 'node-mocks-http';  it('returns 405 on non-POST', async () => {    const { req, res } = createMocks({        method: 'GET',      });        await handler(req, res);      ...  });

Question 2

You can't export like this

You need to import the component first and then exportRailRadar – Live Train Tracking Platform

Question 3

As it’s currently written, your answer is unclear. Pleaseedit to add additional details that will help others understand how this addresses the question asked. You can find more information on how to write good answersin the help center.

Question 4

The error occurs because Jest does not handlenative ES modules (ESM) insidenode_modules by default. Thejose library (used byauth0) is published as ESM-only, so when Jest encounters theexport keyword insidejose/dist/browser/index.js, it throwsUnexpected token 'export'.

By default, Jest ignores everything insidenode_modules for transformation. To fix this, you need to explicitly tell Jest to transformjose instead of skipping it.

The key solution is to update yourjest.config.ts with the following changes:

Configurets-jest (or your transformer) to support ESM by settinguseESM: true.
AddtransformIgnorePatterns so thatjose is not ignored.

Your Jest config should include:

transformIgnorePatterns: ['/node_modules/(?!(jose)/)'] → This tells Jest to transformjose even though it is innode_modules.
transform usingts-jest with{ useESM: true } so TypeScript + ESM files are handled correctly.
extensionsToTreatAsEsm: ['.ts', '.tsx'] so Jest treats your TypeScript files as ESM.

With these changes, Jest will correctly transform thejose package, and theUnexpected token 'export' error will no longer occur.

An alternative approach is to use thejest-esm-transformer package instead ofts-jest. This package is designed to handle ESM modules directly. In that case, you would install it as a dev dependency and configure Jest’stransform to use it.

Vishal KaleriaVishal Kaleria 12 bronze badges · Answer 1 · 2025-09-13 16:44:29Z

0

You can't export like this

You need to import the component first and then exportRailRadar – Live Train Tracking Platform

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editedSep 13 at 16:44

Talha

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answeredSep 12 at 9:12

Vishal KaleriaVishal Kaleria

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Community Sep 12 at 9:59

As it’s currently written, your answer is unclear. Pleaseedit to add additional details that will help others understand how this addresses the question asked. You can find more information on how to write good answersin the help center.

2025-09-12T09:59:11.427Z+00:00

Rahul SinghRahul Singh 11 bronze badge · Answer 2 · 2025-09-13 18:45:37Z

The error occurs because Jest does not handlenative ES modules (ESM) insidenode_modules by default. Thejose library (used byauth0) is published as ESM-only, so when Jest encounters theexport keyword insidejose/dist/browser/index.js, it throwsUnexpected token 'export'.

By default, Jest ignores everything insidenode_modules for transformation. To fix this, you need to explicitly tell Jest to transformjose instead of skipping it.

The key solution is to update yourjest.config.ts with the following changes:

Configurets-jest (or your transformer) to support ESM by settinguseESM: true.
AddtransformIgnorePatterns so thatjose is not ignored.

Your Jest config should include:

transformIgnorePatterns: ['/node_modules/(?!(jose)/)'] → This tells Jest to transformjose even though it is innode_modules.
transform usingts-jest with{ useESM: true } so TypeScript + ESM files are handled correctly.
extensionsToTreatAsEsm: ['.ts', '.tsx'] so Jest treats your TypeScript files as ESM.

With these changes, Jest will correctly transform thejose package, and theUnexpected token 'export' error will no longer occur.

An alternative approach is to use thejest-esm-transformer package instead ofts-jest. This package is designed to handle ESM modules directly. In that case, you would install it as a dev dependency and configure Jest’stransform to use it.

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Nextjs with Jest - unexpected token export

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