Weng

weng.js

var fs = require("fs");
var uglify = require("uglify-js"), 
jsp = uglify.parser,
pro = uglify.uglify;

var code = fs.readFileSync(process.argv[2], "utf8");
var ast = jsp.parse(code);

var varList = new Array();
const literals = ["null", "true", "false", "this"];

var w = pro.ast_walker();
ast = w.with_walkers({
        "name": function(name) {
                function addVar (varN) {
                    if(literals.indexOf(varN) == -1
                        && varList.indexOf(varN) == -1)
                            varList.push(varN);}
                                      
                if(typeof name == "object")
                    addVar(name[0]);
                else
                    addVar(name);
                    
                return [ this[0], name ];
        }
}, function(){
        return w.walk(ast);
});

for(var i = 0; i < varList.length; i++)
{
    console.log(varList[i]);
}