[Bug]: require.main has invalid value null

[jlherren]

Version

29.7.0

Steps to reproduce

git clone https://github.com/jlherren/jest-test
cd jest-test
npm install
node bin/app.js
npm run test

Expected behavior

When running node bin/app.js, it prints "Note that require.main is undefined".

Actual behavior

During npm run test, it prints "Note that require.main is null".

Additional context

According to the nodejs docs, require.main is a reference to the entry module, when the entry script is CJS and undefined otherwise. The value null is not valid for require.main. This confuses some third-party libraries that check for CJS vs ESM with typeof require.main === 'object', (since typeof null is "object"). One such example is umzug, when it loads migration files.

Environment

System:
    OS: Linux 6.1 Debian GNU/Linux 12 (bookworm) 12 (bookworm)
    CPU: (12) x64 Intel(R) Core(TM) i7-8700K CPU @ 3.70GHz
  Binaries:
    Node: 18.20.4 - /usr/bin/node
    Yarn: 1.22.22 - /usr/bin/yarn
    npm: 10.7.0 - /usr/bin/npm
    pnpm: 8.6.5 - /usr/bin/pnpm
  npmPackages:
    jest: ^29.7.0 => 29.7.0

[github-actions]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 30 days.

[jlherren]

This is still happening, including in 30.0.0-alpha.6, although for some reason the console.log message isn't visible anymore. I have updated the test to actually make an assertion.

[github-actions]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 30 days.

[github-actions]

This issue was closed because it has been stalled for 30 days with no activity. Please open a new issue if the issue is still relevant, linking to this one.

[github-actions]

This issue was closed because it has been stalled for 30 days with no activity. Please open a new issue if the issue is still relevant, linking to this one.

[github-actions]

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.
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