juliangarnier/js-beautify

$ pip install jsbeautifier
$ js-beautify file.js

import jsbeautifier
res = jsbeautifier.beautify('your javascript string')
res = jsbeautifier.beautify_file('some_file.js')

opts = jsbeautifier.default_options()
opts.indent_size = 2
res = jsbeautifier.beautify('some javascript', opts)

$ npm -g install js-beautify
$ js-beautify foo.js

$ npm install js-beautify

var beautify = require('js-beautify').js_beautify,
    fs = require('fs');

fs.readFile('foo.js', 'utf8', function (err, data) {
    if (err) {
        throw err;
    }
    console.log(beautify(data, { indent_size: 2 }));
});

CLI Options:
  -f, --file       Input file(s) (Pass '-' for stdin)
  -r, --replace    Write output in-place, replacing input
  -o, --outfile    Write output to file (default stdout)
  --config         Path to config file
  --type           [js|css|html] ["js"]
  -q, --quiet      Suppress logging to stdout
  -h, --help       Show this help
  -v, --version    Show the version

Beautifier Options:
  -s, --indent-size             Indentation size [4]
  -c, --indent-char             Indentation character [" "]
  -l, --indent-level            Initial indentation level [0]
  -t, --indent-with-tabs        Indent with tabs, overrides -s and -c
  -p, --preserve-newlines       Preserve line-breaks (--no-preserve-newlines disables)
  -m, --max-preserve-newlines   Number of line-breaks to be preserved in one chunk [10]
  -P, --space-in-paren          Add padding spaces within paren, ie. f( a, b )
  -j, --jslint-happy            Enable jslint-stricter mode
  -b, --brace-style             [collapse|expand|end-expand] ["collapse"]
  -B, --break-chained-methods   Break chained method calls across subsequent lines
  -k, --keep-array-indentation  Preserve array indentation
  -x, --unescape-strings        Decode printable characters encoded in xNN notation
  -w, --wrap-line-length        Wrap lines at next opportunity after N characters [0]
  -X, --e4x                     Pass E4X xml literals through untouched
  --good-stuff                  Warm the cockles of Crockford's heart

{
    "indent_size": 4,
    "indent_char": " ",
    "indent_level": 0,
    "indent_with_tabs": false,
    "preserve_newlines": true,
    "max_preserve_newlines": 10,
    "jslint_happy": false,
    "brace_style": "collapse",
    "keep_array_indentation": false,
    "keep_function_indentation": false,
    "space_before_conditional": true,
    "break_chained_methods": false,
    "eval_code": false,
    "unescape_strings": false,
    "wrap_line_length": 0
}

// Programmatic access
var beautify_js = require('js-beautify'); // also available under "js" export
var beautify_css = require('js-beautify').css;
var beautify_html = require('js-beautify').html;

// All methods accept two arguments, the string to be beautified, and an options object.

CSS Beautifier Options:
  -s, --indent-size             Indentation size [4]
  -c, --indent-char             Indentation character [" "]

HTML Beautifier Options:
  -s, --indent-size             Indentation size [4]
  -c, --indent-char             Indentation character [" "]
  -b, --brace-style             [collapse|expand|end-expand] ["collapse"]
  -S, --indent-scripts          [keep|separate|normal] ["normal"]
  -w, --wrap-line-length        Maximum characters per line (0 disables) [250]
  -p, --preserve-newlines       Preserve existing line-breaks (--no-preserve-newlines disables)
  -m, --max-preserve-newlines   Maximum number of line-breaks to be preserved in one chunk [10]
  -U, --unformatted             List of tags (defaults to inline) that should not be reformatted