zzet/persey

require 'yaml'
require 'erb'

module Persey
  class MissingEnvVariable < RuntimeError; end

  module Adapters
    class Yaml < Persey::Adapters::Base
      class << self
        def load(file, env)
          begin
            raw_hash = YAML.load(ERB.new(File.read(file)).result)
            symbolize_keys(raw_hash)
          rescue KeyError => e
            _, line, method = /\(erb\):(\d+):in `(.*)'/.match(e.backtrace[0]).to_a
            if method == 'fetch'
              raise MissingEnvVariable.new("Check line ##{line} in #{file}")
            else
              raise e
            end
          end
        end
      end
    end
  end
end