transform.rb

require 'json'
require 'hashie'

def _transform(object, *tasks)
  [*tasks]
    .map { |task| task.respond_to?(:call) ? task : task.first.method(task.last) }
    .reduce { |memo, task| ->(*args) { task.(memo.(*args)) } }
    .call(object)
end

def JSON.read(filename)
  _transform \
    filename,
    [File, :read],
    [JSON, :parse],
    ->(json) do
      new = Hashie::Mash.method(:new)
      json.kind_of?(Array) ? json.map(&new) : new.call(json)
    end
end