check for sql queries

sql_query_assertions.rb

def count_query_reads_for(clazz)
  old = ActiveRecord::Base.logger
  log_stream = StringIO.new
  logger = Logger.new(log_stream)
  ActiveRecord::Base.logger = logger
  yield
  ActiveRecord::Base.logger = old
  logger.close
  log_stream.string.scan(/#{clazz} Load/).size
end

def count_query_updates_for(clazz)
  old = ActiveRecord::Base.logger
  log_stream = StringIO.new
  logger = Logger.new(log_stream)
  ActiveRecord::Base.logger = logger
  yield
  ActiveRecord::Base.logger = old
  logger.close
  log_stream.string.scan(/UPDATE \"#{clazz.constantize.table_name}\"/).size
end

usage_example.rb

    foo = count_query_reads_for("Post") do
      Post.first
    end

    assert_equal foo, 1