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Jest encountered an unexpected token - SyntaxError: Unexpected token 'export'

I'm using jest to test a react TypeScript app.
This is the test I'm running:
import { render, screen } from '#testing-library/react'
import { toBeInTheDocument } from '#testing-library/jest-dom'
import ContextProvider from '../../context/ContextProvider'
import { BrowserRouter } from 'react-router-dom'
import BlogPage from './BlogPage'
describe('BlogPage', () => {
test('Render blog page', () => {
render(
<ContextProvider>
<BrowserRouter>
<BlogPage/>
</BrowserRouter>
</ContextProvider>
)
expect(screen.getByText('In this page you can see some of the last articles I wrote.')).toBeInTheDocument()
})
})
And this is the error I'm getting:
FAIL src/components/blogPage/BlogPage.test.js
● Test suite failed to run
Jest encountered an unexpected token
Jest failed to parse a file. This happens e.g. when your code or its dependencies use non-standard JavaScript syntax, or when Jest is not configured to support such syntax.
Out of the box Jest supports Babel, which will be used to transform your files into valid JS based on your Babel configuration.
By default "node_modules" folder is ignored by transformers.
Here's what you can do:
• If you are trying to use ECMAScript Modules, see https://jestjs.io/docs/ecmascript-modules for how to enable it.
• If you are trying to use TypeScript, see https://jestjs.io/docs/getting-started#using-typescript
• To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.
• If you need a custom transformation specify a "transform" option in your config.
• If you simply want to mock your non-JS modules (e.g. binary assets) you can stub them out with the "moduleNameMapper" config option.
You'll find more details and examples of these config options in the docs:
https://jestjs.io/docs/configuration
For information about custom transformations, see:
https://jestjs.io/docs/code-transformation
Details:
/home/German/Desktop/ger/code/projects/my-website/node_modules/react-markdown/index.js:6
export {uriTransformer} from './lib/uri-transformer.js'
^^^^^^
SyntaxError: Unexpected token 'export'
> 1 | import ReactMarkdown from 'react-markdown'
| ^
2 | import Accordion from 'react-bootstrap/Accordion'
3 |
4 | interface Props {
I understand this is because the library I'm using (react-markdown) doesn't have pre-compiled source code. The thing is I followed the docs (https://jestjs.io/docs/tutorial-react-native#transformignorepatterns-customization) and added the react-markdown folder to the transformIgnorePatterns config and I still get the error.
This is my jest.config.ts file:
import type { Config } from '#jest/types'
const config: Config.InitialOptions = {
verbose: true,
transform: {
'^.+\\.ts?$': 'ts-jest'
},
transformIgnorePatterns: [
'node_modules/(?!react-markdown/)'
]
}
export default config
I tried adding <rootDir> like <rootDir>/node_modules/(?!react-markdown/) and It didn't make a difference.
I also tried configuring jest directly from package.json instead of a jest.config file and It didn't make a difference either.
Then I found this question: Jest transformIgnorePatterns not working, which mentions you need to configure Babel.
I created my app with create-react-app so I didn't have Babel on my app. I installed it and created a babel.config.js file inside of which I put:
module.exports = {
"presets": [
"#babel/preset-env"
]
};
But I still get the error...
I'm running out of ideas. Any clue of how could I solve this?
Full code can be found here: https://github.com/coccagerman/my-website

react-markdown is shipped as js, add babel-jest as a transformer in your jest config
transform: {
'^.+\\.ts?$': 'ts-jest',
"^.+\\.(js|jsx)$": "babel-jest"
},

Configure jest with latest version of d3-path

For some reason, my jest configuration doesn't work with the latest version of d3-path#3.0.1. It worked fine with version 2.0.0. I guess it has something to do with d3-path switching to ESM, but I was already using ES6 in my own code, so I don't get why it suddenly doesn't work anymore. I have the following packages installed:
"dependencies": {
"d3-path": "^3.0.1"
},
"devDependencies": {
"#babel/core": "^7.15.8",
"#babel/preset-env": "^7.15.8",
"babel-jest": "^27.3.1",
"jest": "^27.3.1"
}
My babel.config.js:
module.exports = {
presets: [['#babel/preset-env', {targets: {node: 'current'}}]],
};
My index.js:
import { path } from 'd3-path'
export default () => path()
The test file:
import fn from '../src/index.js'
describe('test', () => {
it('works', () => {
fn()
expect(2 + 2).toBe(4)
})
})
The error message:
({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,jest){export {default as path} from "./path.js";
^^^^^^
SyntaxError: Unexpected token 'export'
> 1 | import { path } from 'd3-path'
To reproduce:
git clone https://github.com/luucvanderzee/jest-problem.git
cd jest-problem
npm i
npm run test
// The test runs without failure- this is because we're currently still using d3-path#2.0.0
npm uninstall d3-path && npm install d3-path // (upgrade to d3-path#3.0.1)
npm run test
// Now the test fails.
How should I configure jest and/or babel to solve this issue?
EDIT:
I already tried the following (from this page of the jest docs):
Creating a jest.config.js file with the following:
module.exports = {
transform: {}
}
Changing my "test" command from "jest" to "node --experimental-vm-modules node_modules/jest/bin/jest.js"
This gives me another error:
/home/luuc/Projects/javascript/jest-problem/test/test.test.js:1
({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,jest){import fn from '../src/index.js'
^^^^^^
SyntaxError: Cannot use import statement outside a module
I also don't get what is meant by
• To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.
Isn't the problem that the module is not transformed? Would adding an ignore pattern not just lead to the module not getting transformed?

Problem
The error happens because jest does not send the content of node_modules to be transformed by babel by default.
The following output line of npm run test indicates one way to solve the problem:
• To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.
Solution
The configuration of jest should be updated in order to instruct it to transform the ESM code present in d3-path dependency.
To do so, add the following to a jest.config.js file in the root directory of the project:
module.exports = {
transformIgnorePatterns: ['node_modules/(?!(d3-path)/)']
}
npm run test runs fine after that.
The transformIgnorePatterns option is documented here.
Edit - including more modules
In order to include all modules starting with d3, the following syntax may be used:
transformIgnorePatterns: ['/node_modules/(?!(d3.*)/)']

TLDR;
transformIgnorePatterns: [
"/node_modules/(?!d3|d3-array|d3-axis|d3-brush|d3-chord|d3-color|d3-contour|d3-delaunay|d3-dispatch|d3-drag|d3-dsv|d3-ease|d3-fetch|d3-force|d3-format|d3-geo|d3-hierarchy|d3-interpolate|d3-path|d3-polygon|d3-quadtree|d3-random|d3-scale|d3-scale-chromatic|d3-selection|d3-shape|d3-time|d3-time-format|d3-timer|d3-transition|d3-zoom}|internmap|d3-delaunay|delaunator|robust-predicates)"
]
For the ones reaching this page after updating recharts dependency, here I found the solution, provided by them.

What causes failure to compile SASS in this svelte applcation?

I am working on a project with Svelte and the material design library Svelte Material UI.
This material design library requires SASS, so I installed a preprocessor with npm install svelte-preprocess and added preprocess: autoPreprocess() in rollup.config.js. So I now have:
plugins: [
svelte({
// enable run-time checks when not in production
dev: !production,
// we'll extract any component CSS out into
// a separate file - better for performance
css: css => {
css.write('public/build/bundle.css');
},
preprocess: autoPreprocess()
}),
routify({ singleBuild : true}),
replace({
// stringify the object
APPENV: JSON.stringify({
isProd: production,
...config().parsed // attached the .env config
}),
}),
// more stuff
]
I have a file smui.js with this content:
import Button from '#smui/button';
import Checkbox from '#smui/checkbox';
import Chips from '#smui/chips';
import Dialog from '#smui/dialog';
import FormField from '#smui/form-field';
import Select from '#smui/select';
export {
Button,
Checkbox,
Chips,
Dialog,
FormField,
Select
}
In my index.svelte file I am importing the above this way: import * as Smui from "../smui.js";.
Instead of a success message with the port on which the app should run, I get:
[!] Error: Unexpected character '#' (Note that you need plugins to import files that are not JavaScript)
node_modules\#smui\dialog\_index.scss (1:0)
1: #import "smui-theme";
^
2: #import "./style";
Error: Unexpected character '#' (Note that you need plugins to import files that are not JavaScript)
What am I doing wrong?

I had the same issue and somehow I managed to fix this with rollup-plugin-postcss plugin. Update your rollup.config.js with the following code and you should have _smui-theme.scss in your one of sass directories.
import postcss from 'rollup-plugin-postcss'
...
plugins: [
svelte({
// enable run-time checks when not in production
dev: !production,
// we'll extract any component CSS out into
// a separate file - better for performance
css: css => {
css.write('public/build/bundle.css')
}
}),
postcss({
extensions: ['.css'],
extract: true,
minimize: true,
use: [['sass', { includePaths: ['./src/(yoursass-directory-name)', './node_modules'] }]]
})

I've never used #import to import components from a NPM package, but at the readme package you're referencing it recommends using 'import x from" svelte-material'. Also pay attention that svelte-preprocess won't be supported by the package you're referencing, take a look at the readme:
To bundle this in your own code, use a Sass processor (not a Sass Svelte preprocessor, but a Sass processor).

jest says cannot import outside a module

I'm attempting make a few functions using the Test Driven Development (TDD)
I am writing in javascript.
checkTransparency(urlString)
maketransparent(urlString)
are two functions of mine I'm trying to test and develop which is located in a file called transcript.js.
These uses the inkscape and graphicsmagick npm. I checked checkTransparent works in some other project of mine, but I'm trying to make sure I can just copy paste this transparent.js into another project and use it elsewhere as well.
My folder structure of the project are the following :
+ node_modules
+ src
--- transparent.js
+ test
--- transparent.spec.js
+ package.json
+ package-lock.json
+ jest.config.js
I am using jest as my test framework.
The problem is when I run jest (or npm test)
I get the following:
FAIL test/transparent.spec.js
● Test suite failed to run
Jest encountered an unexpected token
This usually means that you are trying to import a file which Jest cannot parse, e.g. it's not plain JavaScript.
By default, if Jest sees a Babel config, it will use that to transform your files, ignoring "node_modules".
Here's what you can do:
• To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.
• If you need a custom transformation specify a "transform" option in your config.
• If you simply want to mock your non-JS modules (e.g. binary assets) you can stub them out with the "moduleNameMapper" config option.
You'll find more details and examples of these config options in the docs:
https://jestjs.io/docs/en/configuration.html
Details:
\\..............\transparent\test\transparent.spec.js:4 <FEW DETAILS OMITTED HERE DELIBERATELY>
import { checkTransparency, makeTransparent } from "../src/transparent"; // const transparent = require("../src/transparent");
^^^^^^
SyntaxError: Cannot use import statement outside a module
at Runtime._execModule (C:/Users/Kjeong/AppData/Local/Yarn/Data/global/node_modules/jest-runtime/build/index.js:988:58)
Test Suites: 1 failed, 1 total
Tests: 0 total
Snapshots: 0 total
Time: 0.862s
Ran all test suites.
my jest.config.js:
module.exports = {
testEnvironment: "node",
moduleDirectories: ["node_modules", "src", "transparent"],
moduleFileExtensions: [
"js",
"json",
"jsx",
"ts",
"tsx",
"node"
],
clearMocks: true,
}
I've tried the following exports to get this thing working:
export function checkTransparency(urlString) { ... }
export function makeTransparent(urlString) {... }
module.exports = {
checkTransparency: checkTransparency,
makeTransparent: makeTransparent,
};

In your package.json, using configuration like following could solve your problem:
{
"name": "<blah blah>",
"version": "1.0.0",
"description": "",
"type": "module",
"scripts": {
"start": "node server.js",
"test": "node --experimental-vm-modules node_modules/.bin/jest"
},
}

If you really want to use import keyword then you probably need to follow these explanations. Otherwise why not just require ?
const { checkTransparency, makeTransparent } = require('../src/transparent')
Hope this helps :)

SyntaxError: Unexpected token : when running jest test with Aurelia in TypeScript

Just created a new TypeScript Aurelia project using aurelia-cli .
Installed bootstrap and included bootstrap css in the app.ts using import.
import 'bootstrap/dist/css/bootstrap.min.css';
import '../../static/assets/css/app.scss';
import { routes } from './routes';
interface IApp {
message: string;
}
export class App implements IApp{
message = 'Hello World!';
}
Now when I run the test , I get error unexpected token as below
yarn test
# and the output contains
yarn run v1.12.3
$ nps test
nps is executing `test` : nps test.jest
nps is executing `test.jest` : node node_modules/rimraf/bin.js test/coverage-jest && jest
ts-jest[config] (WARN) TypeScript diagnostics (customize using `[jest-config].globals.ts-jest.diagnostics` option):
message TS151001: If you have issues related to imports, you should consider setting `esModuleInterop` to `true` in your TypeScript configuration file (usually `tsconfig.json`). See https://blogs.msdn.microsoft.com/typescript/2018/01/31/announcing-typescript-2-7/#easier-ecmascript-module-interoperability for more information.
FAIL test/unit/app.spec.ts
● Test suite failed to run
Jest encountered an unexpected token
This usually means that you are trying to import a file which Jest cannot parse, e.g. it's not plain JavaScript.
By default, if Jest sees a Babel config, it will use that to transform your files, ignoring "node_modules".
Here's what you can do:
• To hav`enter code here`e some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.
• If you need a custom transformation specify a "transform" option in your config.
• If you simply want to mock your non-JS modules (e.g. binary assets) you can stub them out with the "moduleNameMapper" config option.
SyntaxError: Unexpected token :
at ScriptTransformer._transformAndBuildScript (node_modules/jest-runtime/build/script_transformer.js:403:17)
at Object.<anonymous> (src/home/app.ts:163:1)
I commented the import bootstrap.css line in app.ts and everything runs fine.
Am I missing some configuration for jest to allow me to use css imports in .ts components?
Here is my jest portion from package.json
"jest": {
"verbose": true,
"roots": [
"<rootDir>/test"
],
"modulePaths": [
"<rootDir>/src",
"<rootDir>/node_modules"
],
"moduleFileExtensions": [
"js",
"json",
"ts"
],
"transform": {
"^.+\\.ts$": "ts-jest"
},
"testRegex": "\\.spec\\.(ts|js)$",
"testPathIgnorePatterns": [
"build",
"dist",
"sample"
],
"setupFiles": [
"<rootDir>/test/jest-pretest.ts"
],
"testEnvironment": "node",
"collectCoverage": true,
"collectCoverageFrom": [
"src/**/*.{js,ts}",
"!**/*.spec.{js,ts}",
"!**/node_modules/**",
"!**/test/**"
],
"coverageDirectory": "<rootDir>/test/coverage-jest",
"coverageReporters": [
"json",
"lcov",
"text",
"html",
"clover"
]
},

I was getting the same error. I resolved my issue by changing the module compilerOption in tsconfig.json from "esnext" to "commonjs". Why am I getting “Unexpected token import” on one webpack project but not the other?