refactoring - find dead JavaScript code?

Question

We are refactoring a legacy web app and as a result are "killing" quite a lot of JavaScript code but we're afraid of deleting what we think is dead code due to not being sure. Is there any tool / technique for positively identifying dead code in JavaScript?

Answer 1

Without looking for anything too complex:

• JSLint (not really a static analyzer, but if you give it your concatenated development code, you'll see what methods are never called, at least in obvious scoping contexts)
• Google Closure Compiler
• Google Closure Linter