Flaky UI tests about notebook HOT 10 OPEN

Thanks @jtpio for the ping.

Wondering if this is only a matter of time for the button to be visible, and if we want to fix it (if it's inconvenient to use) or only fix the test (waiting for the button to be visible).
Did you notice the missing button outside the tests?

from notebook.

Did you notice the missing button outside the tests?

Usually not, so it might indeed just be an issue with the tests.

There is some logic to wait for the kernel status animations to be gone before taking the screenshot, which may not be enough:

But maybe there could indeed also be a check to wait for that button to be visible, just to be sure.

from notebook.

I can take a look at the test and we'll see if it's enough.

from notebook.

Probably related to #6731, see #7371 for details.

from notebook.

Re-opening to keep track of updating to a new JupyterLab version, and check if it fixes the flakiness.

from notebook.

From #7378 (which should include jupyterlab/jupyterlab#16335), it looks like this time it is the button to toggle the virtual scrollbar that is sometimes showing up:

Actual	Expected

from notebook.

it looks like this time it is the button to toggle the virtual scrollbar that is sometimes showing up

I think it is another computation issue with the toolbar, but I can't tell why it was not an issue before.
The debugger is inserted late in the toolbar (because it wait for the debugger to be ready in the kernel).
If it is inserted while the resizer is running (the resizer positions items in the toolbar or in the popup toolbar), the last item is not taken into account during the computation.

from notebook.

Opened jupyterlab/jupyterlab#16409, it fixes this issue locally, during tests and usage.
Too bad that we don't have yet an easy way to run all the tests on CI with this PR...

from notebook.

I hope there will not be other issues with the new change... 😄

from notebook.

Yes, thanks for looking into them!

I'll re-open to keep track of it, which should be fixed after the next JupyterLab update.

from notebook.