Support React 19 ref as prop

[aeharding]

This is a stab at supporting forwardRef and ref-as-prop (react 19).

By defaulting to CustomItemComponentProps ref type to div, this shouldn't have breaking changes for most users.

Note: I also abstracted the types to encourage users to spread onto the custom element. This may be helpful for changes passing other attributes in the future?

If this isn't the approach you want to take, I fully understand (IhavenoideawhatIamdoing), this is mostly to get the conversation started.

[aeharding]

btw, here is a sneak preview of how clean custom virtua item is, with React 19!

import { CustomItemComponentProps } from "virtua";

/**
 * Add data-index to each item for programmatic scrolling
 */
export function IndexedVirtuaItem({
  index,
  ...rest
}: CustomItemComponentProps) {
  return <div data-index={index} {...rest} />;
}

[inokawa]

Thanks for the PR.

This change looks good but it seems that React 19 type has more breaking changes than forwardRef (ex. argument of useRef), and not sure it's stable. So I'd like to release breaking changes to support React 19 at once after 19.0.0 is released. Thanks!

[aeharding]

No problem. FWIW, I am using virtua on my project with React 19 and it works great (except for this typing issue)!

Would you like me to close this for now or leave it open?

[inokawa]

Yeah, it's ok to leave it as is. I might change my mind and merge.

I'm glad to hear virtua worked on React 19!