zhuangbility

Transform string/code into "(([]+{})[+!![]+!![]+!![]])+(([]+![])[+!![]+!![]+!![]])".

Support both Browser and Node.js environment.

NPM page

Travis page

Usage

npm install -g zhuangbility

To String

zhuangbility "foo bar"

Output(may change between different version):

(([]+![])[+[]])+(([]+{})[+!![]])+(([]+{})[+!![]])+(([]+{})[+!![]+!![]+!![]+!![]+!![]+!![]+!![]])+(([]+{})[+!![]+!![]])+(([]+![])[+!![]])+(([]+!![])[+!![]])

then, run the magic (([]+![]...)) code in any JS engine, you will get the input string back:

To Code

Use --runtime if you want generate a runnable code:

# Generate magic code to a file
zhuangbility --runtime "for (let i = 0; i < 100; i++) console.log(`foo-${i}-bar`)" > test.js

# Run the magic code directly
node test.js

NOTE: your code can NOT require other module in code mode. That means:

# Wrong !!!
zhuangbility --runtime "require('fs'); console.log(fs)" > test.js

will get undefined result. It's really a painful restrict for now.

Under the Hood

Hack 1: JS Implicit Conversion

Thanks(F*ck) to the JS Implict Conversion. There lots of magic, such as:

• +[] => 0 (Number)
• []+[] => '' (String)
• ![] => false (Boolean)

To String

[]+... means ''+.... we can get a String value zero with ([]+[]) + (+[]). In JS, String plus a Number, will get number in String version. Also, String plus Boolean will get 'true' or 'false'.

To Number

Easy... true + true === 2. It's says: (!![] + !![]) === 2.

Get a character from string

Now, We can get 'f' by ([]+ ![]) [+[]] (front part []+![] is string 'false', second part +[] is number 0, the whole magic is get first char from a string --- 'false'[0] => 'f')

Let's take full advantage of the above rule:

• []+{}, // '[object Object]'
• []+![], // 'false'
• []+!![], // 'true'
• []+[][[]], // 'undefined'
• []+(+[]+[][[]]), // 'NaN'

Now we have many character: 'abcdefj...' and all number.

Hack 2: Call unescape

You must know that we can't get 'h' with above method. It's lucky that unescape can do. But the problem is how can we call a function with '([...])...' ???

This is the second trick:

1. '[]' is Array object, '[].sort' is a function, '[].sort.constructor' is built-in Function object
2. Function('...') can create a callable object

Keep in mind: [].sort.constructor(...) can create a callable object.

Then, we want have a callable 'unescape':

3. [].sort.constructor('return unescape') is equal to Function('return unescape')
4. Function('return unescape')('%6a') is equal to unescape('%6a')

The last trick is [].sort === []['sort'].

Let's combine all of above:

[]['sort']['constructor']('return unescape')('%...')

You can get all you want...

For more detail, please read the fucking source code.

FAQ

RangeError: Maximum call stack size exceeded

Our magic string ([()][]{}...) is equal to a long expression, which is easily to exceed the default stack size. Use --stack-size=10000000 (such as: node --stack-size=1000000 -f *magic file*) to specify a larger size.

Ref

What the f*ck JavaScript?

Liscence

MIT