Pdf.js: Drop webpack peerDependency from pdfjs-dist project

[hallysonh]

What is the expected behavior?
The pdfjs-dist project should not include webpack as a peerDependency for it can really work without it when loading the scripts from build directory.

What went wrong?
I am using PDFJS in a component to visualize a PDF using Angular 6. No including webpack in my project (I do not need it at all), make a peerDependency warning popup every time I run any npm command or every time anyone install my component.

[nfantone]

Exactly. Having webpack as a "peerDependency" in a distributable package such as this is plain wrong and should be removed.

[timvandermeij]

The peer dependency was added in #9249 because of worker-loader. Could you elaborate a bit on why it's wrong to have it in our repository? I'm fine with removing it if it's sure to not break things.

[nfantone]

Hi, @timvandermeij. Thanks for your reply!

webpack is a build tool and, as such, it usually only makes sense as a "devDependency" - or is otherwise restricted to the build pipeline of the library. Including it as a "peerDependency" means that users need to either install it locally (even though they may not need it/don't care for it) or ignore the warning that pops out every time on npm install.

I am not familiar with worker-loader, so take my comments with a pinch of salt. But if it is like any other webpack loader, they are typically only required as a build configuration step and nothing else. Also, it makes little sense in a context where the library is meant to be used outside the web (like Node).

Is pdf.js acting as a webpack plugin of sorts in some cases? If it _is_, it _might_ make sense to include both the loader and webpack as a dependency. But, even then, I'd argue that that kind of support should be extracted to its own repo/module.

I took the liberty of forking the repo and taking everything webpack related out. It's still working absolutely fine for me in my Node application.

[mishawakerman]

Is there any plan to remove webpack as a dependency. @nfantone did you plan on submitting a PR?

[nfantone]

@mishawakerman I never really received an "official" response to this issue - and I still don't know why webpack is listed as a dependency. My (limited) intuition tells me this is part of a bigger issue where pdf.js is coupled to some part of its implementation that indirectly depends on webpack and needs to be refactored in some way.

[timvandermeij]

This question is also asked on IRC and we got this answer: https://mozilla.logbot.info/pdfjs/20180606#c14862530-c14862541. In short, I'm not really familiar with Webpack bundling itself, but if it's really only for the example I guess we can remove it. Please check if that is the case before submitting a PR though.

[timvandermeij]

Closing since doing this isn't really a good option given that #9248 will return if we do that. Instead, what we should do is #9580 which is discussed in IRC at https://mozilla.logbot.info/pdfjs/20180606#c14862530-c14862634.