Handling Giant Programs: Strategies for Testing Programs

摘要

The primary challenge of testing giant programs lies with regression testing. Perform-ing tests on a new functionality is basically the same process whether the new functionality is in a new program or an old program. You can usually figure out how to tiptoe your way through isolated tweaks to test even the most giant programs. But if you make significant changes and don't have a complete library of regression tests for a giant, legacy program, how can you test it to make sure you haven't broken something? Or, just as important, if you rewrite the program or perform large-scale refactoring, how can you make sure the new version behaves like the old version? These are serious challenges that are perilous to ignore.