fork from captureClicks from @cycle/history, with shadow dom support (you may need a polyfill for `event.composedPath()`)

captureClicks.js

export function captureClicks(callback) {
  const listener = makeClickListener(callback)

  if (typeof window !== 'undefined') {
    document.addEventListener('click', listener, false)
  }
  return () => {
    document.removeEventListener('click', listener)
  }
}

function which(ev) {
  if (typeof window === 'undefined') {
    return false
  }
  const e = ev || window.event
  return e.which === null ? e.button : e.which
}

function sameOrigin(href) {
  if (typeof window === 'undefined') {
    return false
  }

  return href && href.indexOf(window.location.origin) === 0
}

function makeClickListener(callback) {
  return function clickListener(event) {
    if (which(event) !== 1) {
      return
    }

    if (event.metaKey || event.ctrlKey || event.shiftKey) {
      return
    }

    if (event.defaultPrevented) {
      return
    }

    const eventPath = event.composedPath()

    let element = null
    for (let i = 0; i < eventPath.length; i++) {
      const checking = eventPath[i]
      if (checking.tagName === 'A' && checking.href) {
        element = checking
        break
      }
    }

    if (!element || element.nodeName !== 'A') {
      return
    }

    if (
      element.hasAttribute('download') ||
      element.getAttribute('rel') === 'external'
    ) {
      return
    }

    if (element.target) {
      return
    }

    const link = element.getAttribute('href')

    if ((link && link.indexOf('mailto:') > -1) || link.charAt(0) === '#') {
      return
    }

    if (!sameOrigin(element.href)) {
      return
    }

    event.preventDefault()

    const {search, hash = ''} = element
    callback({ event, element, url: link, search, hash })
  }
}