ruby - Ruby: Getting Stack level too deep on YAML.load of hash

Question

I'm using YAML in ruby (1.9.3) to dump and load options used by the application.

The path for the file is stored in a constant in a constants.rb file that gets loaded by the main executable for the app. The options are loaded as a Options class which directly inherits from hash (class Options < Hash).

When I try to load the YAML saved in the options file, I get a SystemStackError: stack too deep (in irb from workspace.rb:80 or from the command line to_ruby.rb:306).

I will put the code for the class below. Glad to have any comments. Thanks

class Options < Hash
  attr_reader :path, :default_content

  def initialize
    @path = LOG_DIR + '/options.yml'
    @default_content = { auto: true, cbz: true, is_set_up: false }

    if File.exists?( @path )
      self.merge!( YAML.load( File.read( @path ) ) )
    else
      load_default
    end
  end

  def update( key, value )
    if self.has_key?( key )
      self[key] = value
      File.open( @path, 'w' ).write( YAML.dump( self ) )
    else
      puts 'That key does not exist'
    end
  end

  def load_default
    # load default options
    self.merge!( @default_content )
  end
end

Options.new

Here is the yaml that is trying to be loaded:

--- !ruby/hash:Options
:auto: true
:cbz: true
:is_set_up: true

Answer 1

Remove this:

--- !ruby/hash:Options

Leaving this:

:auto: true
:cbz: true
:is_set_up: true

That line is a serialized instance of the Options class, and having the Options class load an instance of itself in its initializer is a recipe for stack explosions.

This should get things working:

def update( key, value )
  if self.has_key?( key )
    self[key] = value
    File.open( @path, 'w' ) do |f|
      f.write( to_h.to_yaml )
    end
  else
    puts 'That key does not exist'
  end
end

to_h.to_yaml writes the hash out as YAML. Also, using the block form of File.open ensures the file is closed at the end of the block.