bar.rb

require 'csv'

module SQLAwesome
  class RDBMS
    def self.new_from_csv_dir directory
      tables = {}
      Dir["#{directory.chomp("/")}/*.csv"].each do |file|
        table = []
        CSV.foreach(file, headers: true) { |row| table << row }
        tables[file.split("/").last.chomp(".csv")] = table
      end
      new tables
    end
    
    def initialize table_hash
      @tables= table_hash
    end
    
    def eval sql_str
      raw_ast = Parser.new.parse program
      model = Transformer.new.apply raw_ast
      model.eval self
    end
    
    def [](table)
      @tables[table]
    end
  end
  end
end

foo.md

describe SQLAwesome do
  it "retrieves all columns for all rows with a wildcard" do
    db = SQLAwesome::RDBMS.new_from_csv_dir File.dirname(__FILE__)+"/../data/"
    result = db.eval "SELECT * FROM one_to_five"
    result.each {|row| row.keys.must_equal ["dec", "eng"]
  end
end

B)

describe SQLAwesome do
  it "retrieves all columns for all rows with a wildcard" do
    result = SQLAwesome.eval "SELECT * FROM one_to_five",
                             database: build_database(File.dirname(__FILE__)+"/../data/")
    
    result.each {|row| row.keys.must_equal ["dec", "eng"]
  end
end