JSDOM virtualConsole environment option defunct in parallel mode

🐛 Bug Report

Overriding virtual console for jsdom isn’t possible for parallel execution.

To Reproduce

(Repl.it link further down.)

In any project using jest with at least two test files using jsdom, override the virtual console setting:

In jest.config.js:

    ...
    testEnvironment: "jsdom",
    testEnvironmentOptions: {
        virtualConsole: new require('jsdom').VirtualConsole()
    }
    ...

Then run:

• jest

Expected behavior

The tests run as they should.

Actual behavior

The tests die with an error from JSDOM:

TypeError: options.virtualConsole must be a VirtualConsole (from createVirtualConsole)

(createVirtualConsole is a bug in JSDOM - it should say VirtualConsole AFAIK.)

This looks like a bug in the way Jest fans out test to workers, because if you runs sequentially, it works. To demonstrate this, try:

• jest --runInBand

Link to repl or repo (highly encouraged)

https://repl.it/@mzedeler/Reproducing-virtualConsole-option-bug

Change first line in index.js to switch between passing and failing case.

Issues without a reproduction link are likely to stall.

Run npx envinfo --preset jest

Paste the results here:

  System:
    OS: Linux 4.15 Ubuntu 18.04.1 LTS (Bionic Beaver)
    CPU: (8) x64 Intel(R) Core(TM) i7-4810MQ CPU @ 2.80GHz
  Binaries:
    Node: 12.0.0 - ~/.nvm/versions/node/v12.0.0/bin/node
    Yarn: 1.15.2 - ~/.nvm/versions/node/v12.0.0/bin/yarn
    npm: 6.9.0 - ~/.nvm/versions/node/v12.0.0/bin/npm
  npmPackages:
    jest: 24 => 24.7.1 

This is relate to https://github.com/facebook/jest/issues/5223.

[SimenB]

The bug here is that it works in run-in-band, btw, so I don’t think you’d like the fix 😅 The way parallelized tests work is by running separate processes for them. The only way to communicate between processes is to pass serializable messages (in essence, we do JSON.stringify). This is done on config, so when you do new VirtualConsole, that’s not gonna be sent across, leading to the error you’re seeing in JSDOM. Additionally, as probably noted, when you do new something in the config, that instance is shared across all tests, which you probably don’t want.

I’ll close this as the solution to your issue is to create a custom environment or just stub out console as you noted. We’ll address config silently dropping fields as part of #7185

@SimenB @jeysal Should we add an option for virtualConsole field of testEnvironmentOptions is a function to call in the setup?

See above - the solution in this case is a custom env - we currently do not support non-serializable things (like functions) in the config

[github-actions[bot]]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs. Please note this issue tracker is not a help forum. We recommend using StackOverflow or our discord channel for questions.