Fix tooltip rendering crash when activeItem is undefined

[tran-simon]

Description

Sometimes, the tooltip rendering would crash when the window has been resized

TypeError: Cannot read properties of undefined (reading 'payload')

This is due to a mistake in getItemByXY in generateCategoricalChart.tsx.

recharts/src/chart/generateCategoricalChart.tsx

Lines 2250 to 2252 in 0d5326a

	isFunnel(graphicalItem, activeItem) ||
	isPie(graphicalItem, activeItem) ||
	isScatter(graphicalItem, activeItem)

recharts/src/util/ActiveShapeUtils.tsx

Lines 142 to 152 in 7fb227d

	export function isFunnel(graphicalItem: GraphicalItem, _item: unknown): _item is FunnelItem {
	return 'trapezoids' in graphicalItem.props;
	}
	export function isPie(graphicalItem: GraphicalItem, _item: unknown): _item is PieItem {
	return 'sectors' in graphicalItem.props;
	}
	export function isScatter(graphicalItem: GraphicalItem, _item: unknown): _item is ScatterItem {
	return 'points' in graphicalItem.props;
	}

isFunnel, isPie and isScatter do not check if activeItem is defined, so it might cast it as a defined FunnelItem/PieItem/ScatterItem even if activeItem is undefined

I've added a nullcheck for activeItem

Related Issue

#3981

Motivation and Context

This fixes a crash

How Has This Been Tested?

I manually checked that the crash doesn't happen anymore

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• I have added a storybook story or extended an existing story to show my changes
• All new and existing tests passed.

[ckifer]

instead of doing it this way could we add the check in each is.. function?

That way this is never an issue elsewhere that those typeguards are used.

so for example

 export function isScatter(graphicalItem: GraphicalItem, _item: unknown): _item is ScatterItem { 
   return Boolean(_item) && 'points' in graphicalItem.props; 
 } 

[tran-simon]

Done

I opted for _item != null && ... instead of Boolean(_item) so that it does not fail if _item is 0 or ''

I know that currently _item should be an object, but in case we change it in the future it's better if we only check for null or undefined

[ckifer]

cool, makes sense

[ckifer]

LGTM, thanks for the contribution