scroll-position-in-layout.coffee

import React from 'react'
import debounce from 'underscore-es/debounce'

# fixes @reach/router scrolling issue
update_scroll_position = debounce ->
  history.replaceState { history.state..., scrollY }, document.title
, 100

export default \
class Layout extends React.Component
  componentDidMount: ->
    addEventListener 'scroll', update_scroll_position
    if y = history.state?.scrollY
      scrollTo 0, y
    else
      scrollTo 0, 0 unless document.querySelector location.hash or null

  componentWillUnmount: ->
    removeEventListener 'scroll', update_scroll_position

  render: ->
    <>
      {@props.children}
    </>