Google and a few other companies manage to do this with Closure Library and Closure Compiler. Compiler's static analysis detects a large set of errors that you

Google and a few other companies manage to do this with Closure Library and Closure Compiler. Compiler's static analysis detects a large set of errors that you might introduce after a broken refactoring, or just during normal development. Among the most useful are the missing properties check, and the type mismatch check.