Jest encountered an unexpected token - "import *"

Hi, while trying to run tests, I’m getting an issue. I tried solutions including installing multiple babel packages, configuring them in packages.json, adding .babelrc files, but nothing seems to work.

Jest complains, that the webpack.js from the react-pdf package is not a correct javascript file. Has anyone else had this issue or knows a workaround for the issue?

Error Message: 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:

C:\Code\harmo\my-application\node_modules\react-pdf\dist\esm\entry.webpack.js:1
({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,global,jest){import * as pdfjs from 'pdfjs-dist';
                                                                                                ^`

[jlarmstrongiv]

That’s a great tip! Workaround for create-react-app in package.json:

{
  "jest": {
    "moduleNameMapper": {
      "react-pdf/dist/esm/entry.webpack": "react-pdf",
    }
  }
}

[madelineurl]

Also having this issue, but only when importing pdfs from ‘react-pdf-dist/esm/entry.webpack’ for performance as instructed in the documentation. Importing PDF and Document directly from ‘react-pdf’ works in Jest, but fails in the browser. Vice versa for importing as instructed in the docs