commenting out 'assert' in javascript code

gistfile1.js

var fs = require("fs")
 esprima = require('esprima'),
 escodegen = require('escodegen'),
 estraverse = require('estraverse');
;



function is_assert_call_node(node) {

  if (node.type !== "ExpressionStatement") return false;

  if (!node.expression) return false;

  if (node.expression.type !== "CallExpression") return false;

  if (node.expression.callee.type !== "Identifier") return false;

  return node.expression.callee.name === "assert" ;

}


function remove_assert(input_file,output_file) {

  console.log(" removing assert on file " , input_file);
  
  var code = fs.readFileSync(input_file);
  
  var ast = esprima.parse(code,{ comment : true });
  estraverse.replace(ast, {
  
     enter: function(node, parent) {
  
  
        if (is_assert_call_node(node)) {
  
           var assert_code = escodegen.generate(node , { format : { compact: true }});
           return {
                type: "EmptyStatement" ,
                 "trailingComments" :[
                    { type: "Line", value: "@ASSERT@ " + assert_code   }
                    
                 ]
           };
  
        } else {
           return node;
        }
     },
     leave: function(node, parent) {
  
     }
  });
  
  
  var regenerated_code = escodegen.generate(ast, { comment: true });
  
  fs.writeFileSync(output_file,regenerated_code);
}


var dive = require('dive');
var path = require("path");

dive(process.cwd() + "/lib", { directories: false, files: true }, function(err, file) {
  if (err) throw err;
  if (path.extname(file) !== ".js" ) {
        return ;
  }
  console.log( "processing file : ", file);
  remove_assert(file,file);
});