If you have no tests and cruddy code, then you should probably throw it away and start again because you'll have to do all the testing, as opposed to if you have cruddy code with many tests.
如果你有一堆乱七八糟的代码且又没有试,那么你最好是扔掉头开始,否则你就得重新做所有的试。反,如果你有一堆乱七八糟的代码同时还有试的话,情况就不一样了。