After V19 tooltip inside cdk-virtual-scroll-viewport

[callawey]

ngx-bootstrap:v18.0.2 to v18.1.1 and onwards

Angular: v19

Its very easy to create this problem. Use tooltip inside cdk-virtual-scroll-viewport with large number of items

<i [tooltip]="TEST" placement="right" >

its working very fine with v180.2, but if you upgrade ngx-bootstrap to v18.1.1, cdk-virtual-scroll-viewport completely brokes.

I gues tooltip is doing something new in v18.1.1 It may not a bug in ngx-bootrap but as nothing is documented in changelog, i wonder whats changed and whats causing this.

Also i do a complete check on all the commits between this releases but there is nothing changed except converting them to standalone.

This is realy confusing me, what am i missing here and how can it broke it.

[lexasq]

Hey, thanks for your report, Please provide a link with a proper repoduction of the issue

[callawey]

Sure, here is a reproduction link with ngx-bootstrap 19.0.1

• if you switch to 18.0.2, do a complete refresh to stackblitz to prevent cache issue, its not happening on 18.0.2.

i also put two videos to show whats happening on scrolling.

https://stackblitz.com/edit/stackblitz-starters-ehj1siuj?file=package.json

ngx-bootstrap 18.0.2, no issue on the scrolling https://github.com/user-attachments/assets/58d1213f-d55d-4659-8f6e-88e97c0accb5

ngx-bootstrap 19.0.1, scrolling messed up, all white space https://github.com/user-attachments/assets/c83c3d27-fdb7-44cf-a6a3-ba886a294113

[slubowsky]

FYI - I see what seems to be same issue when using typeahead in cdk-virtual-scroll-viewport. Works as expected using ngx-bootstrap 18.0.2 broken in higher versions.

[lexasq]

So I've made quite a few tests and it seems like a cdk-scroller issue. If you make a very fast scroll - it breaks even if you remove tooltip. Seems like additional directive makes this worse, but the issue isn't on ngx-bootstrap level. cdk-scroller.webm

[raizel-connectbooks]

I'd like to point out that from my own testing it does seem to be a ngx-bootstrap issue. with the cdk-scroller, if you make a very fast scroll - it takes a second to load, even if you remove the tooltip. but it doesnt break. ( this is evident in the cdk-scroller.webm you posted) with the tooltip it breaks. the data doesn't load no matter how long i wait