[BUG] Flickering UI

[trn-dev-1]

Please provide the environment you discovered this bug in.

MacOS 26.2, Microsoft Edge.

Which area/package is the issue in?

button

Description

The button have this issue as in the screen sharing.

Screen.Recording.2026-02-27.at.14.02.18.mov

The code is really simple: it's just a page with this code:

and then navigates to another page, which has a back button.

The issue is due to this line:

Please provide the exception or error you saw

Other information

No response

I would be willing to submit a PR to fix this issue

• Yes
• No

[trn-dev-1]

https://github.com/trn-dev-1/spartan-button-issue

Screen.Recording.2026-02-27.at.14.44.30.mov

The issue is somehow how the cva (or Angular) applies the classes.

In the above screenshot, I'm directly bypassing the classes function and just set the classes value directly.
Please check the about.html component from the above repository.

[trn-dev-1]

@ashley-hunter

If you try something like this, adding the resolved classes on the host, the issue no longer reproduces.

The transition-all class is also present in ShadCn, tho in React, this issue does not happen.

But, if I do something like this, so just a host binding through a class property, the issue is there:

[ashley-hunter]

Yes - so this is something I looked into a while back and I'm really not sure how much there is we can do on our end as I believe the issue was that whenever angular uses a class binding it technically adds all of those classes one at a time so any styles added after the transition was setup were getting animated (mind you this was quite a while ago, so I may be mis-remembering that).

One potential work around could be to sort the classes so any transition classes always are added last - but I haven't tested it and that's assuming I'm remembering the cause of the issue correctly 😅

[goetzrobin]

@ashley-hunter do you think it would make sense for us to try to detect if transition tailwind classes are applied and sort so they're at the end?

[ashley-hunter]

It's worth a try - I haven't verified if that will resolve the issue or not, but worth checking for sure.