DOM ends up replicating ...

[dermotduffy]

Thank you for this super simple and comprehensive way to make transitions work smoothly for Lit components, including the great documentation. Very slick!

I'm using lit-transition to fade a menu in/out. It works great. Occasionally, for reasons I don't know/understand, the menu in question appears to "replicate" rather than animate. That is, the contents of my template end up being reproduced and added a second time to the DOM, then I open the menu again, the contents of the template are added a third time. Then fourth, then fifth, etc. I can see this DOM expanding in Chrome Developer tools.

A reload fixes the issue, and it goes back to modifying the DOM 'in-place' (the animations work beautifully, and I can see the animation updating the DOM in Chrome developer tools).

Nevertheless, it happens again later for unclear reasons. If I remove the call to transition() this replication never happens, so the issue is either some way I am using lit-transition or some issue with it.

Any hints on what might cause this?

You can find the code in question here .

Screenshot of endless template copies:

Thanks again!