Dynamically-created iframe not loading properly in Firefox

[drrnkin]

What is your Scenario?

A test loads a page that dynamically inserts an iframe. element and loads that content. The iframe fails to load.

What is the Current behavior?

In Firefox, the iframe does not load at all (in any version of TestCafe that I have tried; 1.x, 2.x, 3.x).

Note that there's an error about querySelectorAll in the console. In the provided sample, the main.ts file simply imports Highcharts (a popular charting library: https://www.highcharts.com/) and that's enough to cause the issue. I don't have the source so I can't whittle it down further.

What is the Expected behavior?

Simple test at https://github.com/drrnkin/testcafe-iframe should pass. The test should detect the content in the iframe that is dynamically created by a script in the iframe. The test does not pass in Firefox in any version of TestCafe.

Expected: test should pass in Firefox and all other supported browsers.

What is your public website URL? (or attach your complete example)

https://github.com/drrnkin/testcafe-iframe

What is your TestCafe test code?

See provided repo

Your complete configuration file

See provided repo

Your complete test report

No response

Screenshots

No response

Steps to Reproduce

1. Clone the repo https://github.com/drrnkin/testcafe-iframe
2. yarn
3. yarn build
4. yarn test-firefox

TestCafe version

3.3.0

Node.js version

v16.20.2

Command-line arguments

See Steps to Reproduce

Browser name(s) and version(s)

Firefox 116.0.3 (currently latest

Platform(s) and version(s)

Windows 10

Other

Split from #7983 . This one is specific to Firefox.

[github-actions]

We appreciate you taking the time to share the information about this issue. We replicated it, and it is currently in our internal queue. Please note that the research may take time. We'll update this thread once we have news.

[github-actions]

This issue has been automatically marked as stale because it has not had any activity for a long period. It will be closed and archived if no further activity occurs. However, we may return to this issue in the future. If it still affects you or you have any additional information regarding it, please leave a comment and we will keep it open.

[drrnkin]

Commenting to remove stale state