strict_dig.rb

module StrictDig
  def strict_dig(*keys, map: false, strict: true, value_key: false)
    outer_layer   = self
    layers        = value_key ? keys.push(value_key) : keys
    original_keys = layers.dup

    while layers.any?
      current_layer = layers.shift
      fetching_args = strict ? [current_layer] : [current_layer].push(nil)

      inner_layer = if map
        outer_layer.map { |element| element.fetch(*fetching_args) }
      else
        outer_layer.fetch(*fetching_args)
      end

      outer_layer = inner_layer
    end

    inner_layer.is_a?(String) ? inner_layer.strip : inner_layer
  rescue KeyError, IndexError => e
    raise e, "Original strict_dig argument: #{original_keys}. #{e.message.capitalize}."
  end
end

class Array
  include StrictDig
end

class Hash
  include StrictDig
end