transform.js

var escodegen = require('escodegen');
var parse     = require("esprima").parse;
var fs        = require("fs");

var src = fs.readFileSync(
  "test.js",
  "utf-8"
);

var ast = parse(src);
console.log(JSON.stringify(ast, null, ' '));


var output = escodegen.generate(ast, {
  sourceMap         : true,
  sourceMapWithCode : true
});
console.log(output.code);