gistfile1.builder

# in <project_root>/bin/magicwand
MagicWand::Configuration::Initializer.new(...)

# in <project_root>/data/root.yaml
---
apple:   100
banana:  200
coconut: 300

# ----------------------------------
# bad strategy:

# in <project_root>/lib/magicwand/configuration/initializer.rb
root_yaml = YAML.load_file(
  File.expand_path("../../../../data/#{RootFileName}", __FILE__))

# ----------------------------------
# marginally better:

# in lib/magicwand/magicwand.rb
module MagicWand
  # Project root directory.
  ROOT = File.expand_path("../..", __FILE__)
end

# in <project_root>/lib/magicwand/configuration/initializer.rb
root_yaml = YAML.load_file(
  File.expand_path("#{MagicWand::ROOT}/data/#{RootFileName}", __FILE__))