reduce: do not panic on null

[kylebrandt]

also switch to require over assert in testing.

[ryantxu]

for sure better than panic! however ignoring nils for min/max/etc may also be reasonable.

Obviously depends on where the data came from though -- with group by queries it is easy to end up with a bunch of meaningless nils. We could also consider using nullValueMode this was from the UI settings

[aknuds1]

LGTM

[kylebrandt]

for sure better than panic! however ignoring nils for min/max/etc may also be reasonable.

Obviously depends on where the data came from though -- with group by queries it is easy to end up with a bunch of meaningless nils. We could also consider using nullValueMode this was from the UI settings

I agree. Just going with this for now, as dropping/ignoring nils is a bit more complicated (e.g., what do you do when everything is nil).

What I eventually want to have, is dropdowns with some of these options that control various things. So for reduction, stuff like this. For math, eg $A + $B there may be drop downs how to handle various join scenerios between the items in A and the items in B.

So this is just a quick fix, because that thing I made for fun with Azure and showed on Friday panicked, and I had to fix that ;-)