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I'm using Jest to test my React app.

Recently, I added DeckGL to my app. My tests fail with this error:

Test suite failed to run
/my_project/node_modules/deck.gl/src/react/index.js:21
export {default as DeckGL} from './deckgl';
^^^^^^
SyntaxError: Unexpected token export
  at ScriptTransformer._transformAndBuildScript (node_modules/jest-runtime/build/script_transformer.js:318:17)
  at Object.<anonymous> (node_modules/deck.gl/dist/react/deckgl.js:9:14)
  at Object.<anonymous> (node_modules/deck.gl/dist/react/index.js:7:15)
This looks like an issue with Jest transforming a node module before running it's tests. 
Here is my .babelrc:
  "presets": ["react", "es2015", "stage-1"]
Here is my jest setup:
"jest": {
    "testURL": "http://localhost",
    "setupFiles": [
      "./test/jestsetup.js"
    "snapshotSerializers": [
      "<rootDir>/node_modules/enzyme-to-json/serializer"
    "moduleDirectories": [
      "node_modules",
      "/src"
    "moduleNameMapper": {
      "\\.(css|scss)$": "<rootDir>/test/EmptyModule.js"
I seem to have the correct things necessary to transform export {default as DeckGL }. So any ideas whats going wrong? 
                @DonP, can you try using the recommended ts-jest and see if it helps? I don't want to crowd this question with another answer if it doesn't help you out
– Tarun Lalwani
                Apr 6, 2018 at 3:55
                Nothing here helped but github.com/facebook/create-react-app/issues/… mentioned you can pass in transformIgnorePatterns as a command-line argument to npm/yarn/craco in package.json's scripts, and that worked!
– Ahmed Fasih
                Jun 23, 2022 at 20:58
This means, that a file is not transformed through TypeScript compiler, e.g. because it is a JS file with TS syntax, or it is published to npm as uncompiled source files. Here's what you can do.
Adjust your transformIgnorePatterns allowed list:
  "jest": {
    "transformIgnorePatterns": [
      "node_modules/(?!@ngrx|(?!deck.gl)|ng-dynamic)"
By default Jest doesn't transform node_modules, because they should be valid JavaScript files. However, it happens that library authors assume that you'll compile their sources. So you have to tell this to Jest explicitly. Above snippet means that @ngrx, deck and ng-dynamic will be transformed, even though they're node_modules.
                @EladKatz I'm new to this, but I think this block is meant for package.json, and without the 'jest' wrapper you could put it in jest.config.js.
– aweibell
                Sep 23, 2020 at 10:09
                Might just want to simplify the RegExp like this: node_modules\/(?!(@ngrx|deck.gl|ng-dynamic))
– rmolinamir
                Jan 18, 2022 at 7:04
And if you are using 'create-react-app', it won't allow you to specify 'transformIgnorePatterns' via Jest property in package.json
As per this https://github.com/facebook/create-react-app/issues/2537#issuecomment-390341713
You can use CLI as below in your package.json to override and it works :
"scripts": {
  "test": "react-scripts test --transformIgnorePatterns \"node_modules/(?!your-module-name)/\"",
                Worth noting that if you're using react-app-rewired, it takes over the processing for the jest property in package.json, and concatenates rather than replaces. So this solution will not work and you will have to place it in the script options or inside the overrides script
– MichaelM
                Jul 5 at 15:09
This is because Node.js cannot handle ES6 modules.
You should transform your modules to CommonJS therefore.
Babel 7 >=
Install
npm install --save-dev @babel/plugin-transform-modules-commonjs
And to use only for test cases add to .babelrc,
Jest automatically gives NODE_ENV=test global variable.
"env": {
    "test": {
      "plugins": ["@babel/plugin-transform-modules-commonjs"]
Babel 6 >=
npm install --save-dev babel-plugin-transform-es2015-modules-commonjs
to .babelrc
"env": {
    "test": {
      "plugins": ["transform-es2015-modules-commonjs"]
                This works! However, make sure to run jest --clearCache I had to do that before it started working.
– Dan Zuzevich
                Nov 2, 2018 at 16:44
                where do I add:  "env": {     "test": {       "plugins": ["@babel/plugin-transform-modules-commonjs"]     } }
– joeCarpenter
                May 15, 2019 at 1:48
                @joeCarpenter to your .babelrc or to other babel config file you might be using eg babel.config.js. If you don't yet have one you can create new file in the project root with name .babelrc and add this under root {  } -tags.
– Jimi Pajala
                May 15, 2019 at 4:08
                Had to combine this answer with @Ria Anggraini's answer to get things to work when running tests.
– s1mm0t
                Jul 28, 2019 at 20:43
  
Default: ["/node_modules/"]
  
An array of regexp pattern strings that are matched against all source
  file paths before transformation. If the test path matches any of the
  patterns, it will not be transformed.Default: ["/node_modules/"]
DeckGL seems to be in ES6, to make jest able to read it, you need to compile this as well.

To do that, just add an exception for DeckGL in the transformignorePatterns
"transformIgnorePatterns": ["/node_modules/(?!deck\.gl)"]
https://facebook.github.io/jest/docs/en/configuration.html#transformignorepatterns-array-string
It was work around #1 on this page that fixed it for me though workaround #2 on that page is mentioned in above answers so they may also be valid.
"Specify the entry for the commonjs version of the corresponding package in the moduleNameMapper configuration"
jest.config.js
    moduleNameMapper: {
        "^uuid$": require.resolve("uuid"), 
        "^jsonpath-plus$": require.resolve("jsonpath-plus") 
In my case I use this config in the file package.json:
"jest": {
    "transformIgnorePatterns": [
      "!node_modules/"
                Does Jest really give special meaning to a preceding ! in transformIgnorePatterns? I'd guess this is effectively equivalent to writing transformIgnorePatterns: [].
– ominug
                Apr 6 at 18:06
                Great answer. FYI if you want to exclude everything but your workspace you can write the pattern like this: "!node_modules/(?!@src/*.)"
– kernel
                Aug 22 at 11:15
                Thanks for pointing that out. It worked for me after renaming the file and adding the exception for my esm library in transformIgnorePatterns!
– Evgeniya Manolova
                Jul 6 at 12:10
I had the exact same problem when using jest with vite+swc and a component using the d3 library (d3-array and d3-shape was having a problem).
This advice to add this to jest.config.js solved it:
transformIgnorePatterns: ['node_modules/(?!@ngrx|(?!deck.gl)|d3-scale)'],
This got me wondering why this worked because I don't use ngrx or deck.gl.
But then I noticed that this is equivalent to:
 transformIgnorePatterns: ['(?!abc|(?!def))'],
The advice also works:
transformIgnorePatterns: ['!node_modules/'],
Which led me to the final answer of
transformIgnorePatterns: [],
Just adding this line with an empty array is the simplest answer which worked.
I was upgrading a project that uses a version of babel that reads the config from .babelrc, when I upgraded to a newer version I read:
https://babeljs.io/docs/en/configuration#whats-your-use-case
What's your use case?
You are using a monorepo?
You want to compile node_modules?
babel.config.json is for you!
On top of:
  "jest": {
    "transformIgnorePatterns": [
      "node_modules/(?!(module))"
I renamed .babelrc to babel.config.json too.
      "modules": "commonjs", // <- Check and see if you have this line
      "targets": {
        "browsers": ["> 1%", "last 2 versions", "not ie <= 8"]
    "stage-2"
  "plugins": ["transform-vue-jsx", "transform-runtime"],
  "env": {
    "test": {
      "presets": ["env", "stage-2"],
      "plugins": ["transform-vue-jsx", "transform-es2015-modules-commonjs", "dynamic-import-node"]
jest understands commonJs so it needs babel to transform the code for it before use. Also jest uses caching when running code. So make sure you run jest --clearCache before running jest.
Tested Environment:

Node v8.13.0

Babel v6+

Jest v27
I'm using a monorepo (it contains multiple packages for the frontend and backend).
The package I'm testing imports a file from another package that uses the dependency uuid.
All the files are in Typescript (not Javascript).
The package I'm testing has a tsconfig file for testing only, called tsconfig.test.json. It has the properties commonjs and allowJs. Adding allowJs solves the problem when importing uuid, I don't know why.
  "extends": "./tsconfig.json",
  "compilerOptions": {
    "outDir": "../../dist/out-tsc",
    "module": "commonjs",
    "types": [
      "jest",
      "node"
    // Necessary to import dependency uuid using CommonJS
    "allowJs": true
  "include": [
    "jest.config.ts",
    "**/*.test.ts",
    "**/*.d.ts"
I got same error. Library A gave such error. I did not use this library in my code directly. I played with jest config a lot of time.
But I found that I forget to mock library B in ...test.tsx file. After mocking there was not that error. Sounds pretty stupid but it works for me.
I had the same problem after upgrading 2 projects from Angular 12 to Angular 14 and 15.
After much searching, the ONLY thing that turned both projects in good ones  again was by upgrading the 'Rxjs' package to a newer/newest version. The ONLY thing.
Be sure to have that RxJs upgraded. After that I made sure to have the tslib upgraded as well.
The base Jest configuration was via this course.
I had the exact same problem when using jest 29.7.0 with React 18.
In my case this config worked after changing the .babelrc into babel.config.js
module.exports = {
  "jest": {
    "transformIgnorePatterns": [
      "node_modules/(?!(module))"
SyntaxError: Unexpected token 'export'
I made sure my jest was properly installed and set up, as per Next.js docs, but still same issue. None of the popular solutions here were working for me either.
However, while running npm i, I noticed this warning:
npm WARN EBADENGINE Unsupported engine {
npm WARN EBADENGINE   package: '[email protected]',
npm WARN EBADENGINE   required: { node: '>=18' },
npm WARN EBADENGINE   current: { node: 'v16.19.1', npm: '8.19.3' }
npm WARN EBADENGINE }
Since version 6.0.0, the flat package is distributed in ECMAScript modules.
Solution
The quickest way to fix it was to downgrade it to a version that is compatible with my node.js and my project settings:
npm i flat@5
And since then I've been able to run jest as expected (perhaps updating the node.js version would've solved it too).
I had the same error of importing dataSet from vis-data.js library
import { DataSet } from 'vis-data/esnext';
So I just removed /esnext from the path and now it works:
import { DataSet } from 'vis-data';
        
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