Is there any such standalone package for Javascript, like PyFlakes for Python? I see there is JsLint, but it looks like it depends on some external things like Rhino.
I prefer something basic&compact like PyFlakes, because it shows me 80% of bugs I make and has only 20% (or even less) of complexity of other tools like PyLint.
Ideally it should also have a working recipe for plugging into Emacs, but I can figure it out myself if the tool itself is promising.
If you want a standalone version of JSLint, take a look at my jslint4java project. It embeds rhino and JSLint into an executable jar file.
The is also an example of using it with emacs in this gist.