Add CI testing with GitHub Actions

[tzanio]

We should add smoke test for

• building on Linux, Mac
• code styling
• ...

[tzanio]

It will be great if we test the actual usage, e.g. compare screenshots of pre-defined datasets as a form of regression testing.

[tzanio]

We should also test the glvis-js and pyglvis repos

[adrienbernede]

Current status is that we have Github Actions to build glvis. This is not running or testing it, and definitely not comparing screenshots. GLVis-js and pyglvis is yet another topic.

I suggest we keep this issue open, or split it in 2 in GLVis:

• Add basic testing of GLVis, once built in actions (done in Introduce automated testing with GitHub Actions #164)
• Investigate screenshot comparison as a testing method (done in [DO NOT MERGE] Regression testing + screenshot fix #176)

and 2 in GLVis-js and pyglvis:

• Test GLVis-js (done in Add CI testing with GitHub Actions glvis-js#7)
• Test pyglvis (done in hhttps://github.com/Add CI testing with GitHub Actions pyglvis#17)

[tzanio]

I think we can close this after #176 is merged. Do you agree @adrienbernede?

[adrienbernede]

I agree! Awesome leap forward!

[tzanio]

Discussion continued in #176