Debug console stops automatically scrolling sometimes when contents wrap

[DanTup]

Splitting from #115945.

• Clone mock-debug
• Run the tests
• Resize the window so the debug console has lots of wrapping
• Run the tests again

After a few tests run, the Debug Console will stop scrolling down automatically and just remain part-way through.

[isidorn]

Danny Tuppeny (@DanTup) thanks for steps I can reproduce this.

João Moreno (@joaomoreno) here I am hitting the limitation of what the tree gives me. Currently I use the following heurisitc to figure out if the last element is visible in the tree

const lastElementVisible = (this.tree.scrollTop + this.tree.renderHeight) >= this.tree.scrollHeight;

However that does not give the correct result when elements are wrapped and take additional lines.
So I could either somehow update that check, or I could use the tree.lastElementVisible. I would just care if there are elements after the last visible element, but I could not figure out any tree api to get next neighbour of the last visible element. Might I be missing something? Let me know what you think, thanks.

[joaomoreno]

However that does not give the correct result when elements are wrapped and take additional lines.

Isidor Nikolic (@isidorn) What 3 values does it return in that case?

[isidorn]

João Moreno (@joaomoreno) In this step we are good:

scroll top: 89
render height: 151
scroll height: 240

In the next step we are no longer good:

scroll top: 121
render height: 151
scroll height: 280

[isidorn]

João Moreno (@joaomoreno) and me investigated into this and it seems to be related to how async code is handled on the list side.
Thus assigning this to on-deck and once João Moreno (@joaomoreno) finds time he can look into a fix or recommend a workaround for me on the Debug Console side.