Visual regression testing / check if jdaviz application renders with jupyter lab 3.0

[maartenbreddels]

This is based on https://github.com/maartenbreddels/ipyvolume/pull/355 and https://github.com/bqplot/bqplot/pull/1311

And is using:

• https://github.com/jupyterlab/galata

It will start up jupyter lab, and use galata to execute the notebook, take a screenshot, and compare that to the screenshot in the repo.

@eteq expressed his concerns about the growth of the size of the repo if we have to push a lot of images.

[pllim]

app_ipynb_cell_0.png is a screenshot of some warning... is that intentional?

[maartenbreddels]

Good catch, I filtered the warning, since it includes the path (and thus will fail).

[maartenbreddels]

It seems we get some false positives due to some rendering 'artifacts' on the bottom of the jupyter lab interfaces:

Capture:

Reference:

I'll open an issue at Galata, and leave it for now until we decide we want to merge this/have it in CI.