[Bug]: Automock breaking instanceof comparisons in transitive dependencies of mocked module

[liamjones]

Version

29.7.0

Steps to reproduce

1. Clone https://github.com/liamjones/RealmMockIssue
2. npm install
3. npm run test

Expected behavior

Test passes

Actual behavior

Test will fail with Illegal constructor: Results objects are read from managed objects only. (this comes from an instanceof check failing inside the realm module)

Additional context

Commenting out the auto-mocking of the hasRatedThisVersion file that has an import Realm from 'realm' inside it: https://github.com/liamjones/RealmMockIssue/blob/main/__tests__/realm.test.ts#L6 results in the instanceof check passing.

Providing a factory function for the mock (so auto-mocking doesn't kick in) also fixes the instanceof check.

I originally reported this to the Realm project (realm/realm-js#6122 (comment)) and one of the realm module devs has provided a more detailed explanation of how/where the instanceof check is failing in their code: realm/realm-js#6122 (comment)

After digging into the auto-mock code & searching for existing Jest issues I found the bug re differing globals across VM contexts: #2549 (comment). It seems similar, but I'm not sure it's the same issue. Realm itself isn't being mocked, just a module that imports it.

I do understand that if a Realm.Results in one VM context was compared to another via instanceof then the check would fail, and this is intended behaviour (nodejs/node-v0.x-archive#1277). However, I don't get how, if Realm is being initialised in a new VM context under the auto-mocked module, it'd be 'leaking' out to the version of the realm module in the test context.

Environment

System:
    OS: macOS 15.1.1
    CPU: (16) x64 Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz
  Binaries:
    Node: 20.11.1 - ~/.volta/tools/image/node/20.11.1/bin/node
    Yarn: 4.0.2 - ~/.volta/tools/image/yarn/4.0.2/bin/yarn
    npm: 10.2.4 - ~/.volta/tools/image/node/20.11.1/bin/npm
    pnpm: 9.1.1 - ~/.volta/bin/pnpm
    bun: 1.1.38 - /usr/local/bin/bun
  npmPackages:
    jest: ^29.6.3 => 29.7.0