capitalizeCityName.js

const capitalizeExeptions = ['dc']
export const capitalizeCityName = string => {
  if (!string) return ''
  string = string.toLowerCase()
  if (string.includes(' ')) {
    return string
      .split(' ')
      .reduce((result, word) => `${result && `${result} `}${capitalizeCityName(word)}`, '')
  }
  if (capitalizeExeptions.includes(string)) {
    return string.toUpperCase()
  }
  const [first, ...rest] = string

  return first.toUpperCase() + rest.join('')
}

parseRouteUrl.js

export const decodeCityPath = cityPath => cityPath.replace(/_/g, ' ').toLowerCase()

export const parseRouteUrl = path => {
  if (!/[a-z_!,]+-[a-z_!,]+-\d{6}/.test(path)) return null

  const parts = path.split('-')

  let date = parts[parts.length - 1]
  date = new Date(`${date.slice(0, 2)}/${date.slice(2, 4)}/${date.slice(4)}`)
  if (!isValid(date)) return null

  return {
    from: capitalizeCityName(decodeCityPath(parts[0])),
    to: capitalizeCityName(decodeCityPath(parts[1])),
    date,
  }
}