Function scrollIntoView

packages/react-select/src/utils.ts:264–286

(
  menuEl: HTMLElement,
  focusedEl: HTMLElement
)

// ------------------------------

export function scrollIntoView(
  menuEl: HTMLElement,
  focusedEl: HTMLElement
): void {
  const menuRect = menuEl.getBoundingClientRect();
  const focusedRect = focusedEl.getBoundingClientRect();
  const overScroll = focusedEl.offsetHeight / 3;

  if (focusedRect.bottom + overScroll > menuRect.bottom) {
    scrollTo(
      menuEl,
      Math.min(
        focusedEl.offsetTop +
          focusedEl.clientHeight -
          menuEl.offsetHeight +
          overScroll,
        menuEl.scrollHeight
      )
    );
  } else if (focusedRect.top - overScroll < menuRect.top) {
    scrollTo(menuEl, Math.max(focusedEl.offsetTop - overScroll, 0));
  }
}

// ==============================
// Get bounding client object