Разобрался сам, если кому интересно:

function makeAddressString(address) {
  if (address.region == address.city) {
    return join([
      address.city,
      address.settlement_with_type,
      address.street_with_type
    ])
  } else {
    if (address.city) {
      return join([
        address.city,
        address.settlement_with_type,
        address.street_with_type
      ])
    } else {
      return join([
        address.area_with_type,
        address.settlement_with_type,
        address.street
      ])
    }
  }
}

Разобрался сам, извините за беспокойство!