When to rewrite a code base from scratch

Question

I think back to Joel Spolsky\'s article about never rewriting code from scratch. To sum up his argument: The code doesn\'t get rusty, and while it may not look pretty afte

Answer 1

Instead of a complete rewrite from scratch you want to start refactoring the code base in small steps while introducing unit tests. For example

1. Move duplicate code into a common class with tests for resuse throughout the project
2. Introduce interfaces to create separate testable modules. You can then refactor the implementation behind the interface while relying on your tests to ensure you don't break anything.