MethodAccessibleHash, a possible replacement for OpenStruct

method_accessible_hash.rb

# OpenStruct has caveats and security problems and even leads to a rubocop offense:
# https://ruby-doc.org/stdlib-3.1.0/libdoc/ostruct/rdoc/OpenStruct.html#class-OpenStruct-label-Caveats
# https://msp-greg.github.io/rubocop/RuboCop/Cop/Style/OpenStructUse.html
#
# It's time to replace it. The feature I loved most about OpenStruct was being able to retrieve
# values by calling a method instead of having to use hash access syntax.
# The recommended way to go is Struct, but it is much more cumbersome than OpenStruct was.
# So here's MethodAccessibleHash that allows to do that, but without OpenStruct's security problems.
#
# This revision adds writers, direct creation from Hash, as well as enhanced merging.
#
# License: MIT
# Feel free to use this code anywhere you like. No warranty provided.
#
# Usage example:
# default_options = { foo: :bar }
# options = MethodAccessibleHash.new(default_options)
# options[:color] = :green
# options.foo # => :bar
# options.color # => green

class MethodAccessibleHash < ::Hash
  # Takes an optional hash as argument and constructs a new
  # MethodAccessibleHash.
  def initialize(hash = {})
    super()

    hash.each do |key, value|
      self[key.to_sym] = value
    end
  end

  # @private
  def merge(hash)
    super(hash.symbolize_keys)
  end

  # @private
  def method_missing(method, *args, &_block)
    if method.end_with?('=')
      name = method.to_s.gsub(/=$/, '')
      self[name.to_sym] = args.first
    else
      self[method.to_sym]
    end
  end

  # @private
  def respond_to_missing?(_method, _include_private = false)
    true
  end
end