jekyll_6364.rb

# This is a possible alternate solution to Jekyll #6364.
# All of these procs are translations of methods from Jekyll::Filters.
# Only item_property has been modified.

require "liquid"

input = { "government" => ["one post", "two post"], "tech" => ["three post"], "lol" => [1,2,3] }

as_liquid = -> (item) {
  case item
  when Hash
    pairs = item.map { |k, v| as_liquid.([k, v]) }
    Hash[pairs]
  when Array
    item.map { |i| as_liquid.(i) }
  else
    if item.respond_to?(:to_liquid)
      liquidated = item.to_liquid
      # prevent infinite recursion for simple types (which return `self`)
      if liquidated == item
        item
      else
        as_liquid.(liquidated)
      end
    else
      item
    end
  end
}

item_property = -> (item, property) {
  if item.respond_to?(:to_liquid)
    property.to_s.split(".").reduce(item.to_liquid) do |subvalue, attribute|
      p attribute
      liquid = as_liquid.(subvalue)
      liquid.respond_to?(attribute) ? liquid.public_send(attribute) : liquid[attribute]
    end
  elsif item.respond_to?(:data)
    item.data[property.to_s]
  else
    item[property.to_s]
  end
}

sort_input = -> (input, property, order) {
  interim = input.map { |item| [item_property.(item, property), item] }
  p interim
  interim.sort! do |apple_info, orange_info|
      apple_property = apple_info.first
      orange_property = orange_info.first

      if !apple_property.nil? && orange_property.nil?
        - order
      elsif apple_property.nil? && !orange_property.nil?
        + order
      else
        apple_property <=> orange_property
      end
    end
    .map!(&:last)
}

sort = -> (input, property = nil, nils = "first") {
  if input.nil?
    raise ArgumentError, "Cannot sort a null object."
  end
  if property.nil?
    input.sort
  else
    if nils == "first"
      order = - 1
    elsif nils == "last"
      order = + 1
    else
      raise ArgumentError, "Invalid nils order: " \
        "'#{nils}' is not a valid nils order. It must be 'first' or 'last'."
    end

    sort_input.(input, property, order)
  end
}

p input
p sort.(input, "last.length")