Esformatter-rename NPM

esformatter-rename

Esformatter plugin to rename variables, parameters, and labels

This was built to make comprehending deobfuscated scripts easier (e.g. rename a to jQuery). It is based off its sister project esformatter-phonetic which renames variables to pronouncable equivalents (also good for deobfuscating scripts).

Features:

Supports ES6 arrow functions (e.g. (a) => a + 1)
Supports let (e.g. let a = 1;)
Supports destructured variables (e.g. var {a, b} = obj;)

Getting Started

Install the module with: npm install esformatter-rename

Then, register it as a plugin and format your JS:

// Load and register our plugin
var esformatter = require('esformatter');
var esformatterRename = require('esformatter-rename');
esformatter.register(esformatterRename);

// Format our code
esformatter.format([
  'function myFn() {',
    'var a = \'hello\';',
    'console.log(a);',
  '}'
].join('\n'), {
  rename: {
    variables: {
      a: 'hello'
    }
  }
});
/*
function myFn() {
  var hello = 'hello';
  console.log(hello);
}
*/

Alternatively, load it via format or .esformatter:

{
  plugins: [
    'esformatter-rename'
  ]
}

Documentation

esformatter-rename exposes exports.transform for consumption by esformatter.

Options

We provide the following options to configure esformatter-rename during transformation. These should be stored under rename in your esformatter options.

variables Object - Key value pairing of original variable name to new name
- For example variables: {hello: 'world'} will rename all hello variables to world variables
  - function hello() { console.log('hai'); } -> function world() { console.log('hai'); }
- If you are potentially doing something dangerous (e.g. renaming an undeclared variable), we will warn you/skip it since it can have global reprecussions)
  - These warnings can be ignored and actions can be taken via the related option
labels Object - Key value pairing of origin label name to new name
- For example labels: {loop1: 'myLoop'} will rename all loop1 labels to myLoop
  - loop1: while (true) { break loop1; } -> myLoop: while (true) { break myLoop; }
renameTopLevel Boolean - Allow for renaming of top level variables (i.e. anything declared with a var in the global scope)
- If true, renaming is allowed. If false, it is not and a warning is logged.
- By default, this is false.
renameUndeclared Boolean - Allow for renaming of undeclared variables (e.g. variable referenced without a var)
- If true, renaming is allowed. If false, it is not and a warning is logged.
- By default, this is false.
ignoreWith Boolean - Allow for renaming of variables that were referenced at least once in a with
- For example var obj = {}; var hello; with (obj) { hello(); } will not allow renaming of hello
- If true, renaming is allowed. If false, it is not and a warning is logged.
- By default, this is false.

Examples

Renaming `jQuery`

In this example, we will rest jQuery from its normal convention of $ to the full name jQuery.

Script before renaming:

console.log($('#main').text());

Formatter options:

{
  rename: {
    variables: {
      '$': 'jQuery'
    },
    renameUndeclared: true
  }
}

Script after renaming:

console.log(jQuery('#main').text());

Contributing

In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint via grunt and test via npm test.