Nested groups collapse/uncollapse not working

[strazto]

Heres a jsbin

When clicking the group, the collapse/uncollapse styling seems to toggle, but besides that, there's no change.

[strazto]

I've looked at it more closely, and I'm finding it hard to see where the actual showing/hiding of the nested groups is handled https://github.com/yotamberk/timeline-plus/blame/master/lib/timeline/component/ItemSet.js#L1809

I'm new to javascript, though, so I may just be missing something about the way it handles events.
is it possible that this behaviour got removed, somehow?

[strazto]

Yo I fixed it but I also added dependencies on js-logger, js-logger-babel, and on jest and testcafe.

I'm not sure if you're open to a PR with all these new dependencies.

I'm pretty careful with commit-cleanliness and should be able to get rid of all of the logging content, but personally I'm of the opinion that a test-driven policy might be of benefit for maintaining this package, since it seems like you're dealing with regression bugs quite regularly.

I'll make the PR, please get back to me either way

[strazto]

EDIT, fixed it again, properly this time #119

[sbusch]

Wrapping the groups in a DataSet resolves the problem: JS Bin

[strazto]

@sbusch , interesting note.

It does fix the behaviour, and seems simpler than my fix, but it still indicates buggy behaviour, right? At some point are the groups not being treated as DataSets