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I have looked around on numerous forums and for some reason no matter what i try nothing will work. My files are all over the place but i will try to provide as much detail as i can.
The Full error message i get from my app.test.js includes:
● 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:
SyntaxError: <PATH>\314\src\components\Navbar\navStyles.css: Support for the experimental syntax 'decorators' isn't currently enabled (1:1):
> 1 | @font-face {
2 | font-family: 'nunito_extralightregular';
3 | src: url('Navbar.js') format('woff2'),
4 | url('Navbar.js') format('woff');
Add @babel/plugin-proposal-decorators (https://github.com/babel/babel/tree/main/packages/babel-plugin-proposal-decorators) to the 'plugins' section of your Babel config to enable transformation.
If you want to leave it as-is, add @babel/plugin-syntax-decorators (https://github.com/babel/babel/tree/main/packages/babel-plugin-syntax-decorators) to the 'plugins' section to enable parsing.
5 | import { useContext, useState } from "react";
6 | import { Box, IconButton, Typography, useTheme } from "@mui/material";
> 7 | import "./navStyles.css";
9 | const Navbar = () => {
at instantiate (node_modules/@babel/parser/src/parse-error/credentials.ts:62:21)
at instantiate (node_modules/@babel/parser/src/parse-error.ts:60:12)
at Parser.toParseError [as raise] (node_modules/@babel/parser/src/tokenizer/index.ts:1490:19)
at Parser.raise [as expectOnePlugin] (node_modules/@babel/parser/src/tokenizer/index.ts:1550:18)
at Parser.expectOnePlugin [as parseDecorator] (node_modules/@babel/parser/src/parser/statement.ts:731:10)
at Parser.parseDecorator [as parseDecorators] (node_modules/@babel/parser/src/parser/statement.ts:710:28)
at Parser.parseDecorators [as parseStatementLike] (node_modules/@babel/parser/src/parser/statement.ts:415:25)
at Parser.parseStatementLike [as parseModuleItem] (node_modules/@babel/parser/src/parser/statement.ts:354:17)
at Parser.parseModuleItem [as parseBlockOrModuleBlockBody] (node_modules/@babel/parser/src/parser/statement.ts:1359:16)
at Parser.parseBlockOrModuleBlockBody [as parseBlockBody] (node_modules/@babel/parser/src/parser/statement.ts:1333:10)
at Parser.parseBlockBody [as parseProgram] (node_modules/@babel/parser/src/parser/statement.ts:226:10)
at Parser.parseProgram [as parseTopLevel] (node_modules/@babel/parser/src/parser/statement.ts:208:25)
at Parser.parseTopLevel [as parse] (node_modules/@babel/parser/src/parser/index.ts:45:10)
at parse (node_modules/@babel/parser/src/index.ts:67:38)
at parser (node_modules/@babel/core/src/parser/index.ts:28:19)
at parser.next (<anonymous>)
at normalizeFile (node_modules/@babel/core/src/transformation/normalize-file.ts:51:24)
at normalizeFile.next (<anonymous>)
at run (node_modules/@babel/core/src/transformation/index.ts:38:36)
at run.next (<anonymous>)
at transform (node_modules/@babel/core/src/transform.ts:29:20)
at transform.next (<anonymous>)
at evaluateSync (node_modules/gensync/index.js:251:28)
at sync (node_modules/gensync/index.js:89:14)
at fn (node_modules/@babel/core/src/errors/rewrite-stack-trace.ts:97:14)
at transformSync (node_modules/@babel/core/src/transform.ts:66:52)
at Object.require (src/components/Navbar/Navbar.js:7:1)
at Object.require (__tests__/app.test.js:3:1)
babel.config.json file:
"presets": ["@babel/preset-env", "@babel/preset-react"],
"plugins": [
["@babel/plugin-proposal-decorators", { "legacy": true }]
jest.config.js file:
module.exports = {
testEnvironment: 'jsdom',
testEnvironmentOptions: {
userAgent: 'node.js',
resources: 'usable',
runScripts: 'dangerously',
rootDir: '.',
modulePaths: [ '<rootDir>' ],
moduleDirectories: [ 'node_modules', 'src' ],
setupFilesAfterEnv: [ '<rootDir>/setupJest.js' ],
transformIgnorePatterns: [ '/node_modules/' ],
webpack.config.js file:
module.exports = {
mode: 'production',
module: {
rules: [{ test: /\.js$/, use: ['babel-loader'] }],
Within my package.json file, this is the babel and jest dependencies;
"devDependencies": {
"@babel/core": "^7.21.8",
"@babel/plugin-proposal-decorators": "^7.21.0",
"@testing-library/jest-dom": "^5.16.5",
"@testing-library/react": "^14.0.0",
"jest": "^29.5.0",
"jest-environment-jsdom": "^29.5.0",
"jest-fetch-mock": "^3.0.3"
And my current app.test.js file:
import { render, fireEvent } from "@testing-library/react";
import React from 'react';
import NavBar from '../src/components/Navbar/Navbar';
// Import component files
describe( NavBar , () => {
test("user clicks on home button, refreshing page, or, returning home", () => {
const { getByTestId } = render(<NavBar />);
// eslint-disable-next-line testing-library/prefer-screen-queries
const homeLink = getByTestId('home');
fireEvent.click(homeLink);
expect(homeLink).toBeInTheDocument();
I have tried to uninstall and reinstall all packages making sure to have jest and jest-environment-jsdom be the same version which fixed one error. I have tried changing the { "legacy": true }
to { "decoratorsBeforeExport": true }
. Im not sure what else im doing wrong
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