Pdf.js: getDocument hangs in Jest/JSDom environment

Created on 18 Mar 2018 · 4Comments · Source: mozilla/pdf.js

On PDF.js 2.0.385 and later, running the following simplest example:

pdf.getDocument({ data: arrayBufferData })
  .then(() => console.log('Success'))
  .catch() => console.log('Fail'));

runs fine on Node.js, obviously.

Running the same piece in Jest, as in this example (simplified, please ignore the fact the tests should be async):

describe('Test', () => {
  it('does something', () => {
    pdf.getDocument({ data: arrayBufferData })
      .then(() => console.log('Success'))
      .catch() => console.log('Fail'));
  });
}

if testEnvironment is set to "node", succeeds.
if testEnvironment is set to "jsdom" (default), hangs and never reaches .then().

On PDF.js 2.0.305 and earlier this is not an issue, because you can easily disable workers manually.

Now that there's no way of doing that via config as of #9385, all projects using PDF.js and Jest/JSDom will be unable to test anything PDF.js-related. Switching testEnvironment to "node" is usually not an option as this will cause virtually everything else on front-end to fail.

1-core

Source

wojtekmaj

Most helpful comment

I've managed to deal with it! For those stuck like me, do NOT set pdfjs.GlobalWorkerOptions.workerSrc or pdfjs.GlobalWorkerOptions.workerPort. Instead, use pdf.worker.entry.js file - simply import it and you're done!

wojtekmaj on 2 Apr 2018

👍5 ❤4 🎉4

All 4 comments

As mentioned in both ISSUE_TEMPLATE.md and CONTRIBUTING.md:
For issues with custom implementations, you need to provide access to a complete, and small, runnable example for the issue to be actionable. And please don't assume that people are familiar with various JS frameworks, in this case "Jest".

Without any context or code, the following questions comes to mind:
Are workers supported, and if so have you tried to set the workerSrc option and just run tests with workers enabled?
Have you tried using the workerPort option to load the worker file? Keep in mind that it's also possible to pass a worker to getDocument, see https://github.com/mozilla/pdf.js/blob/0d391daccc2f4e4b9c91268e719bd10fe63a49ae/src/display/api.js#L129-L130