Line Chart : crash when hovering an empty chart that is interactive

[akassaei]

Describe/explain the bug
When hovering a Line Chart with empty data, the chart crashes.

To Reproduce
Here is the link to a Codesandbox showing the issue : https://codesandbox.io/p/sandbox/charming-mendel-3wsx4v?file=%2Fsrc%2Fcomponents%2FLineChart.js%3A110%2C25

Steps to reproduce the behavior:

1. Create a Line Chart with empty Data
2. Hover the Chart with your mouse
3. See the crash

Expected behavior
No crash 😅

Additional context
I spotted where the issue is coming from : basically the findNode method in Mesh hooks relies on d3-delaunay and specifically on delaunay.find method. With no data points given, the .find returns NaN and it isn't a case checked in the code so we try to access the node related to the index and it crashes because it's undefined.

nivo/packages/voronoi/src/hooks.ts

Lines 172 to 179 in da6d6b7

	const findNode = useCallback(
	(event: MouseEvent<ElementType> | TouchEvent<ElementType>): null | [number, Node] => {
	if (!elementRef.current) return null
	const [x, y] = getRelativeCursor(elementRef.current, event)
	let index: number | null = delaunay.find(x, y)
	let node = index !== undefined ? nodes[index] : null

I've already opened an issue on d3-delaunay side because I don't think NaN is really an expected behavior 😅 You can find the issue opened here : d3/d3-delaunay#144

On our side, I've patched Nivo to return null when nodes.length === 0. So I have a fix ready if you want me to handle it, but I'm not sure that's how you want to handle it 😄

[gercog1]

hey @akassaei!

Did you find a quick workaround for this one?

I am also struggling ;)

[robiscoding]

Any update here?