2.7.570 breaks builds for React apps built with Create-React-App (CRA)

I am using React PDF Viewer, which is based on pdf.js at its core, within a React app created with CRA. Which basically means, that there is Webpack working under the hood, abstracted away through CRA.

Now everything works fine up to 2.6.347, but starting with 2.7.570 and also with 2.8.335 I am running into this error:

./node_modules/pdfjs-dist/build/pdf.js 3657:145
Module parse failed: Unexpected token (3657:145)
File was processed with these loaders:
 * ./node_modules/react-scripts/node_modules/babel-loader/lib/index.js
You may need an additional loader to handle the result of these loaders.
|               numPages: this._numPages,
|               annotationStorage: (annotationStorage === null || annotationStorage === void 0 ? void 0 : annotationStorage.getAll()) || null,
>               filename: ((_this$_fullReader = this._fullReader) === null || _this$_fullReader === void 0 ? void 0 : _this$_fullReader.filename) ?? null
|             }).finally(() => {
|               if (annotationStorage) {

I don’t expect anyone here to provide support for either the react package nor CRA. However, as I could clearly identify 2.7.570 as the “deal breaker”, I suspect there has been some change that makes a re-configuration of Webpack necessary?

Glad to receive any feedback that could help to shed some light on the root cause 😃

Thank you

[dominik-bln]

@aspnetde Ah, thank you, that clears it up. Another thing to add to the list that will only work with Webpack 5.

[aspnetde]

@dominik-bln See https://github.com/react-pdf-viewer/react-pdf-viewer/issues/499#issuecomment-819568264