[core] feat(MenuItem): forward MenuProps to submenu

[bvandercar-vt]

Fixes #5335

Checklist

• Includes tests
• Update documentation

Changes proposed in this pull request:

Allow menuProps to be passed to MenuItem that get forwarded to the Menu created within the Popover button.

[adidahiya]

we don't need & object... that's a weird quirk from an older version of TypeScript that's no longer necessary.

[adidahiya]

also I think we should call this prop submenuProps

Suggested change

	menuProps?: Partial<MenuProps> & object;
	submenuProps?: Partial<MenuProps>;

[bvandercar-vt]

I agree with the name change.

So the issue with just Partial<MenuProps> is that MenuProps doesn't have the commonly used prop data-testid. Any Ideas on how we can get that in there?

[adidahiya]

hmm, there's no good way to do that in the object type. data-* attributes work in JSX because they're built into React. I guess you can leave the & object in this type and leave a note in the JSDoc about why it's there.

[bvandercar-vt]

How would you describe that? Like this?
/**
* Props to spread to the child Menu component if this item has a submenu.
* & object allows for data-* attributes to be passed.
*/

[adidahiya]

actually, it's an implementation detail, so it should be a code comment for devs rather than JSDoc:

Suggested change

	*/
	menuProps?: Partial<MenuProps> & object;
	*/
	// note that `& object` is required to allow attributes built-in to JSX like "data-testid"
	submenuProps?: Partial<MenuProps> & object;

[bvandercar-vt]

I'm just going to remove the & object, that actually didn't solve it. Just Partial<MenuProps> is fine.