Support Web Workers coming from node_modules

Choose one: is this a 🐛 bug report or 🙋 feature request?

Both, I guess?

🤔 Expected Behavior

• node_modules should be also checked when looking for a file

😯 Current Behavior

• trying to refer to a Service Worker file from node_modules fails with the following error:

×  C:\Users\wojtekmaj\Projekty\react-pdf\sample\parcel\node_modules\react-pdf\build\entry.parcel.js: Cannot resolve dependency './pdfjs-dist\build\pdf.worker.js' (...)

what it is trying to do is look for the path in ./ but not in node_modules.

🔦 Context

💻 Code Sample

I’m currently working on support for Parcel in React-PDF. That requires me to handle loading a service worker which is not mine.

In Webpack, the following code does the job:

var pdfjs = require('react-pdf/build/pdf.js');
var PdfjsWorker = require('worker-loader!react-pdf/build/pdf.worker.js');

if (typeof window !== 'undefined' && 'Worker' in window) {
  pdfjs.PDFJS.workerPort = new PdfjsWorker();
}

I was trying to reproduce the same using Parcel, and here’s what I got so far:

const pdfjs = require('pdfjs-dist');

if (typeof window !== 'undefined' && 'Worker' in window) {
  pdfjs.PDFJS.workerPort = new Worker('pdfjs-dist/build/pdf.worker.js');
}

This results in an error described below. Changing the line to

pdfjs.PDFJS.workerPort = new Worker('../node_modules/pdfjs-dist/build/pdf.worker.js');

stops the error, but:

• I’m not comfortable with relative path in a package like that
• This caused… a 404 error! Parcel starts referring to a file it did not produced.

🌍 Your Environment

Software	Version(s)
Parcel	1.5.0
Node	9.3.0
npm/Yarn	npm, newest
Operating System	Windows 10

[MikeYermolayev]

@mischnic yep. Had to reject using that library

[mischnic]

@devongovett Inspired by the new resolver:

• "~/node_modules/pdfjs-dist/build/pdf.worker.js" for “[…/]node_modules/pdfjs-dist/build/pdf.worker.js”
• "lib/worker.js" = "./lib/worker.js" for relative paths