Chromium based browsers freeze when pxt is removed from DOM

[barbero-oe]

The browser's tab freezes when pxt is removed from the DOM. This happens on chromium based browsers. It does not happen in firefox.

To Reproduce

1. Clone pxt repository (https://github.com/microsoft/pxt.git)
2. Clone pxt sample (https://github.com/microsoft/pxt-sample.git)
   • The folder structure should look like this:
   • bug-report/ |- pxt/ |- pxt-sample/
3. Install pxt globally (npm install -g pxt)
4. Install dependencies on both projects
5. Build local pxt (cd pxt; npm run build)
6. Link pxt-sample with local pxt (Deletion of pxt-sample/node_modules/pxt-core/ might be necessary)
   • cd pxt-sample; pxt link ../pxt
7. Serve pxt-sample with custom pxt
   • pxt serve
8. Open on Chrome the controller example
   • http://localhost:3232/controller.html
9. Remove iframe node from browser console

   document.getElementById('iframe').parentElement.removeChild(document.getElementById('iframe'))

10. The browser window should be unresponsive at this moment

Desktop:

• OS: macOS Big Sur Version 11.2.1
• Browser:
  • Google Chrome Version 89.0.4389.90 (Official Build) (x86_64)
  • Brave Version 1.21.77 Chromium: 89.0.4389.90 (Official Build) (x86_64)

Additional questions

Should I send a message to pxt before closing? If so, which one?

[jfo8000]

Are you sure this is not a bug in chrome devtools?
I definitely had some bad weather with freezing devtools for a few releases.