This would also have the side benefit of being able to produce better designed search results.
EDIT: I suppose searching the AST wouldn't be enough, you would have to evaluate the code to some extent to be able to search these properties.
The situation is uniquely bad in JavaScript, since JavaScript doesn't formally have modules, functions can take any number of arguments, there's the funky scoping, and so forth. Not that good tools don't exist, but it makes it difficult for a JS IDE to enable working across files like a Java IDE can.
That being said, I've found the language a pleasure to work with (aside from browser incompatibility issues) and with the proper application of design principles such as modularity (check out require.js and the r.js optimizer) and, yes, DRY, I can be just as productive, if not more so, in JavaScript as I am in any statically-typed language.
EDIT: Also C# (so many languages, I can't even remember which ones I've used sometimes). I'm also not including TypeScript or Dart (optional static typing), which I've technically "tried", but don't know much about.
For example, in Haskell you can write code as if you're in a dynamic language without annotating all the types and yet you get all of the benefits of types. It's the best of both worlds.
Concluding that static languages suck after using java and c++ et al is a common mistake, and is understandable.
What I did say was that I can be just as productive in those languages as I am in JavaScript, if not more so. It remains to be seen whether I can gain more productivity with TypeScript or Dart.