It depends on your tools. I refactor JS stuff in intelliJ from time to time, no big deal, at least for rename. (1) OTOH, if you don't have plugins for things

It depends on your tools. I refactor JS stuff in intelliJ from time to time, no big deal, at least for rename. (1) OTOH, if you don't have plugins for things like Struts or Spring (faking the desperately needed dynamicism in config files), good luck safely refactoring your "static" typed Java (2). But once have "trained" your IDE where to look, you are back in business again. 1: it's easier to refactor JS if you restrict the scope of identifiers, of course. For starters, this means NOT naively making every function and variable in the global namespace and/or scattered in inline <script> fragments. 2: many other languages dragged into these discussions since there is some general philosophy of compile time vs runtime types discussed on this page.