Question

Is there a recommended javascript code obfuscation tool?

I have searched it in stackoverflow,and someone suggest the ‘YUI compressor’.

However it just do the following:

1. remove the annotatation/white space/new line

2. replace local variable

3. or something ele.

But It does not replace the property of one object.

Say I have a code like this:

var a=obj.fun();
var b=obj.pro;

I want something like this:

var xxx,yy,zz;
xxx=obj['yy']();
yy=obj['zz'];

Then even people re-format my code,he can not even know the propery/methods of one object unless he re-do the method/property replacement.

This is just an example, I just want the tool do more obfuscation other than just compress.

Any suggestion?

Answer 1

You should try the google closure compiler, it provides three levels of writing:

1. The first one is WHITESPACE_ONLY
2. The second one is SIMPLE_OPTIMIZATIONS
3. The third one is ADVANCED_OPTIMIZATIONS

WHITESPACE_ONLY removes comments, trim line breaks and unnecessary spaces. The output code is identical to the source JavaScript.

SIMPLE_OPTIMIZATIONS also renames local variable and function parameters.

ADVANCED_OPTIMIZATIONS is the most aggresive, besides the optimization in the above two levels, it also does:

• global variable renaming
• remove uncalled functions
• function inlining

For the give example:

//INPUT CODE
function unusedFunction(note) {
  alert(note['text']);
}

function displayNoteTitle(note) {
  alert(note['title']);
}

var flowerNote = {};
flowerNote['title'] = "Flowers";
displayNoteTitle(flowerNote);

WHITESPACE_ONLY result is :

//WHITESPACE_ONLY OUTPUT CODE
function unusedFunction(note){alert(note["text"])}function displayNoteTitle(note){alert(note["title"])}var flowerNote={};flowerNote["title"]="Flowers";displayNoteTitle(flowerNote);

SIMPLE_OPTIMIZATIONS result is:

//SIMPLE_OPTIMIZATIONS OUTPUT CODE
function unusedFunction(a){alert(a.text)}function displayNoteTitle(a){alert(a.title)}var flowerNote={title:"Flowers"};displayNoteTitle(flowerNote);

ADVANCED_OPTIMIZATIONS result is:

//ADVANCED_OPTIMIZATIONS OUTPUT CODE
alert("Flowers");

I think the SIMPLE_OPTIMIZATIONS and ADVANCED_OPTIMIZATIONS meet your need.