[Bug]: workerThreads break --watch-all when function does not meet expected.

[roffelund]

Version

29.6.2

Steps to reproduce

1. Clone my repo at: https://github.com/roffelund/jest-function-expect-bug
2. yarn
3. yarn test test.test.js --watch-all

Expected behavior

I expected the test to show that the expected and received do not match.

Actual behavior

Test stops running with exception

Additional context

This only happens when running with workers. Turning off workers expected behaviour works fine.

Environment

System:
    OS: macOS 13.4
    CPU: (10) arm64 Apple M1 Pro
  Binaries:
    Node: 18.17.0 - /opt/homebrew/opt/node@18/bin/node
    Yarn: 1.22.19 - /opt/homebrew/bin/yarn
    npm: 9.6.7 - /opt/homebrew/opt/node@18/bin/npm
  npmPackages:
    jest: 29.6.2 => 29.6.2

[mrazauskas]

Thanks for the reproduction! I saw this happening, but didn’t had time to figure out what was the exact cause. Huge objects were around, so it was difficult to reason about.

Seems like serialization fails somewhere in the threads worker, because all is smooth with workerThreads: false.

[mrazauskas]

By the way, could you mention in the title that the issue is specifically related with workerThreads, not just workers in general.

[roffelund]

Thanks for the reproduction! I saw this happening, but didn’t had time to figure out what was the exact cause. Huge objects were around, so it was difficult to reason about.

Seems like serialization fails somewhere in the threads worker, because all is smooth with workerThreads: false.

Took some debugging to narrow it down. As you say workerThreads: false all is smooth sailing.

[dj-stormtrooper]

Hey, I tried to fix this issue here, would appreciate any feedback/suggestions https://github.com/jestjs/jest/pull/14436/