How to refactor a Delphi unit with 10000 lines with no documentation?

Question

I have been assigned the task to refactor a Delphi unit. Wow. 10000 lines of code, no documentation, tons of copy and paste code.

THere are many methods made with copy a

Answer 1

Start out small and eventually do a partial or full rewrite. Start creating base classes to accomplish pieces of the puzzle without changing the output. Rinse-repeat until you have a new, supportable codebase. Once you hit those copy-n-paste routines, you'll have base classes to do the work and it'll really help accelerate the task.