props-variations.tsx

type TagProps<Tag extends keyof JSX.IntrinsicElements> = {
  is: Tag;
  innerRef?: JSX.IntrinsicElements[Tag]['ref'];
} & JSX.IntrinsicElements[Tag];

type StatelessComponentProps<P> = {
  is: SFC<P>;
} & P;

type ComponentClassProps<T, P> = {
  is: ComponentClass<P>;
  innerRef?: (instance: T | null) => any;
} & P;