Jest Fails to Parse TypeScript Files with ES Module Syntax

[bcostaaa01]

Description:

Hey all. I'm encountering an issue where Jest fails to parse TypeScript files that use ES module syntax. I am using shadcn in a Webpack-scaffolded React project. The error message indicates that Jest encountered an unexpected token when trying to parse an [import] statement in a TypeScript file, however I can't seem to find why it is triggering that issue. I tried different approaches, modifying the babel, jest, and even the TypeScript config, but no success :(

Error Message:

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:

frontend\src\shadcn\components\ui\skeleton.tsx:1
({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,jest){import * as React from 'react';
                                                                                  ^^^^^^

SyntaxError: Cannot use import statement outside a module

Steps to Reproduce the Error:

1. Create a TypeScript file with ES module syntax, e.g., [skeleton.tsx]:

   import * as React from 'react';
   import { cn } from '../../../lib/utils';
   
   function Skeleton({
       className,
       ...props
   }: React.HTMLAttributes<HTMLDivElement>) {
       return (
           <div
               className={cn('animate-pulse rounded-md bg-muted', className)}
               {...props}
           />
       );
   }
   
   export { Skeleton };

2. Import and use this component in another file, e.g., [ComponentThatUsesSkeleton.jsx]:

   import React from 'react';
   import { Skeleton } from '../../shadcn/components/ui/skeleton';
   
   const ComponentThatUsesSkeleton = () => {
       return (
           <div className="flex flex-col w-full h-full items-center gap-8 ">
               <div className="flex  justify-between  w-full  ">
                   <div>
                       <Skeleton className=" w-32 h-10  bg-gray-300 rounded-md " />
                   </div>
                   <div className="flex gap-2">
                       <Skeleton />
                   </div>
               </div>
               <Skeleton />
           </div>
       );
   };
   
   export default ComponentThatUsesSkeleton;

3. Run Jest tests.

Configuration Files:

• [tsconfig.json]

  {
      "compilerOptions": {
          "target": "es6",
          "module": "commonjs",
          "baseUrl": "./src",
          "paths": {
              "@/*": ["*"]
          },
          "jsx": "react",
          "moduleResolution": "node",
          "esModuleInterop": true,
          "skipLibCheck": true,
          "forceConsistentCasingInFileNames": true,
          "strict": true
      },
      "include": ["src/**/*", "jest.polyfills.js"],
      "exclude": ["node_modules", "build"]
  }

• [jest.config.js]:

  module.exports = {
      clearMocks: true,
      testEnvironment: 'jest-environment-jsdom',
      setupFilesAfterEnv: ['<rootDir>/src/setupTests.js'],
      testMatch: ['**/?(*.)+(spec|test).[jt]s?(x)'],
      transformIgnorePatterns: [
          '/node_modules/(?!react-dnd|dnd-core|@react-dnd)/',
      ],
      transform: {
          '^.+\\.[tj]sx?$': 'babel-jest',
      },
      moduleDirectories: ['node_modules', 'src'],
      moduleFileExtensions: ['js', 'jsx', 'ts', 'tsx', 'json', 'node'],
      moduleNameMapper: {
          '^@/(.*)$': '<rootDir>/src/$1',
      },
      resetMocks: true,
  };

• [.babelrc]:

  {
      "assumptions": {
          "setPublicClassFields": true
      },
      "presets": [
          [
              "@babel/preset-env",
              {
                  "useBuiltIns": "entry",
                  "corejs": "3.22.6",
                  "bugfixes": true
              }
          ],
          [
              "@babel/preset-react",
              {
                  "runtime": "automatic"
              }
          ],
          "@babel/preset-typescript"
      ],
      "plugins": [
          "@babel/plugin-transform-runtime",
          [
              "@babel/plugin-proposal-decorators",
              {
                  "legacy": true
              }
          ]
      ]
  }

• [babel.config.js]:

  module.exports = {
      presets: [
          '@babel/preset-env',
          '@babel/preset-react',
          '@babel/preset-typescript'
      ],
      plugins: [
          '@babel/plugin-transform-runtime'
      ]
  };

Expected Behavior:
I guess that Jest should correctly parse and run tests on TypeScript files that use ES module syntax.

Actual Behavior:
Jest fails to parse TypeScript files with ES module syntax, resulting in a SyntaxError: Cannot use import statement outside a module.

Thank you in advance! :)