Is the feature relevant to the Firefox PDF Viewer?

No

Feature description

It would be nice if the pdf.js package would define Package Exports in its package.json file. In essence, this allows to specify both which modules (or files) can be imported from a package depending on the runtime environment.
This would make it a lot easier to load pdf.js in a variety of situations, such as Node.js, webpack, or modern browsers, which right now all require different workarounds (like importing from the legacy/ folder, or setting the worker src, and so on).

Without further research, the exports for pdf.js might look like this:

"exports": {
  ".": {
    "import": "build/pdf.mjs",
    "require": "legacy/pdf.min.mjs",
    "browser": "build/pdf.min.mjs",
    "worker": "build/pdf.worker.min.mjs",
    "types": "types/src/pdf.d.ts",
    "node": "legacy/pdf.mjs",
    "webpack": "webpack.mjs"
  },
  "./viewer": {
    "import": "web/pdf_viewer.mjs",
    "styles": "web/pdf_viewer.css",
    "types": "web/pdf_viewer.d.mts",
    "require": "legacy/web/pdf_viewer.mjs"
  }
}

With exports defined, the package as installed from npm would allow two exports:

• import ... from 'pdfjs-dist';
• import ... from 'pdfjs-dist/viewer';

The source file the above import statement resolves to depends on the runtime environment. This could be a lot more granular and I'm sure I made some wrong assumptions above, since I'm not very familiar with the code base.
I just wanted to bring this up as a possible ergonomics improvement here.

Other PDF viewers

No response