In my Webpack 5-built app, when in the development mode, I've seen the browser request assets using a URL with an app:// scheme. Here's an example:

app:///node_modules/dir/to/package/index.js

For those apps, I also saw the actual tree under app:// in the Debugger tab of the devtools, under Sources:

I noticed that this app:// tree only shows under Sources when the build is in the development mode (the app uses Webpack 5), so it does seem related to Webpack, but I can't find anything in the Webpack docs about it.

In fact, it seems almost impossible to find anything online about app:// (which is quite intriguing!), so I suspect it is indeed Webpack-specific and just badly/not documented.

Does anyone know anything about it?

Thanks!