babel-core/lib/babel/helpers/normalize-ast.js

Turn ES6 code into readable vanilla ES5 with source maps

var t = require("../types");

module.exports = function (ast, comments, tokens) {
  if (ast && ast.type === "Program") {
    return t.file(ast, comments || [], tokens || []);
  } else {
    throw new Error("Not a valid ast?");
  }
};