Mouse event data for 'pie' and 'sankey' plots doesn't return curveNumber or pointNumber

[alishobeiri]

An example of sankey plot, view console for hover event output:
https://codepen.io/monfera/pen/VbKrXM

The hover event for a sankey plot currently returns:

The hover event for a pie plot currently returns (from Dash):

Both types of eventData don't include curveNumber or pointNumber.

In the case that there is more than one pie or sankey trace per plot it isn't possible to identify which trace triggered the mouse event without having access to the curveNumber and ideally the pointNumber as well.

From what I was able to find I think the issue stems from here:

plotly.js/src/components/fx/hover.js

Line 172 in 3e83252

if((subplot === 'pie' || subplot === 'sankey') && !noHoverEvent) {

[etpinard]

Thanks for pointing this out.

The event data for these two trace types is a big mess!