React 16 throws error when extending and overriding getParentElement

Describe the bug DOM element checks were added in React so on React@16.4.2 when using the suggested override for a custom scroll parent element you will receive this error in the console:

Warning: React does not recognize the `scrollParent` prop on a DOM element. If you intentionally want it to appear in the DOM as a custom attribute, spell it as lowercase `scrollparent` instead. If you accidentally passed it from a parent component, remove it from the DOM element.

To Reproduce

1. Clone this repo
2. Under docs/package.json upgrade to react@16.4.2
3. Run the demo and you should get the error

Expected behavior No console error

Device (please complete the following information):

• OS Mac
• Browser Chrome
• Version 69.0.3497.100

Suggested fix To move the class override to a prop with the same name. Effectively it’s the same solution, just how to pass the function through. If people agree with moving it to a prop, I’ll have a pull request out in the next few days.

[k2snowman69]

You shouldn’t also derive new React components based on inheritance which means the suggested solution shouldn’t be to extend the base component.

A possible middle ground would be to pass a function that returns the scroll view. So the prop would be getScrollElement. That way the React component itself isn’t being passed through nor is the component being extended.

[k2snowman69]

Based on your thumbs-up I moved it to using a prop function. Whenever you get a chance… https://github.com/CassetteRocks/react-infinite-scroller/pull/179