function getClippingRect()

in src/anchored-position.ts [178:213]

• 31 lines of code
• 8 McCabe index (conditional complexity)

function getClippingRect(element: Element): BoxPosition {
  let parentNode: typeof element.parentNode = element
  while (parentNode !== null) {
    if (parentNode === document.body) {
      break
    }
    const parentNodeStyle = getComputedStyle(parentNode as Element)
    if (parentNodeStyle.overflow !== 'visible') {
      break
    }
    parentNode = parentNode.parentNode
  }
  const clippingNode = parentNode === document.body || !(parentNode instanceof HTMLElement) ? document.body : parentNode

  const elemRect = clippingNode.getBoundingClientRect()
  const elemStyle = getComputedStyle(clippingNode)

  const [borderTop, borderLeft, borderRight, borderBottom] = [
    elemStyle.borderTopWidth,
    elemStyle.borderLeftWidth,
    elemStyle.borderRightWidth,
    elemStyle.borderBottomWidth
  ].map(v => parseInt(v, 10) || 0)

  return {
    top: elemRect.top + borderTop,
    left: elemRect.left + borderLeft,
    width: elemRect.width - borderRight - borderLeft,

    // If the clipping node is document.body, it can expand to the full height of the window
    height: Math.max(
      elemRect.height - borderTop - borderBottom,
      clippingNode === document.body ? window.innerHeight : -Infinity
    )
  }
}