[Bug]: structuredClone changes type of RegExp

[marekdedic]

Version

29.7.0

Steps to reproduce

test("Minimal", async () => {
  const defaultExclude = /node_modules/;
  expect(defaultExclude instanceof RegExp).toBe(true); // ok
  expect(structuredClone(defaultExclude) instanceof RegExp).toBe(true); // error
});

Expected behavior

Expected structuredClone not to change the type of the RegExp.

Actual behavior

It does.

Additional context

Discovered as part of vitejs/vite#18875
Probably related to #2549

Environment

System:
    OS: Linux 6.8 Ubuntu 24.04.1 LTS 24.04.1 LTS (Noble Numbat)
    CPU: (12) x64 12th Gen Intel(R) Core(TM) i7-1265U
  Binaries:
    Node: 22.11.0 - /usr/bin/node
    Yarn: 1.22.21 - /usr/bin/yarn
    npm: 10.9.1 - /usr/bin/npm
  npmPackages:
    jest: ^29.7.0 => 29.7.0

[mrazauskas]

Try using jest-light-runner as suggested in #2549 (comment). If that helps, most likely you have hit #2549.

[marekdedic]

While trying to run with jest-light-runner I get:

 FAIL  __tests__/basic.test.ts
  ● Test suite failed to run

    thrown: Object {}

but I'm not sure if it's the underlying issue or just some incompatibility with jest-light-runner, I've never used it before and there isn't anything to debug this.

Original PR I'm trying it on: marekdedic/rollup-plugin-htaccess#170