recase

Deep re-key Objects and Arrays as either camel case or snake case.
In short:

{ "fooBar": [
    { "baz": 1 }
  , { "_quxQuuxCorgeGrault": { "garplyWaldoFred": "plughXyzzyThud" } }
  ]
}

becomes:

{ "foo_bar": [
    { "baz": 1 }
  , { "_qux_quux_corge_grault": { "garply_waldo_fred": "plughXyzzyThud" } }
  ]
}

And can be converted back.
Note that leading underscores _ are considered as convention for private / special vars and are ingnored when changing case.
If I ever support CamelCaps (first letter capital) I might use leading $ for private / special.This example works in both the Browser and Node

(function (exports) {
  'use strict';

  var Recase = exports.Recase || require('recase')
    , recase = Recase.create({ exceptions: { FOO: 'foo'} })
    , snake
    , camel
    , _ = exports._ || require('lodash')
    ;

  snake = recase.snakeCopy(
    {
      FOO: 1                // Exception
    , abcXyz: {             // Normal
        _abcXyz: [          // private
          { __abcXyz: 1 }   // very private
        , { ___abcXyz: 1 }   // very very private
        ]
      }
    }
  );

  camel = recase.camelCopy(
    {
      foo: 1                // Exception
    , abc_xyz: {             // Normal
        _abc_xyz: [          // private
          { __abc_xyz: 1 }   // very private
        , { ___abc_xyz: 1 }   // very very private
        ]
      }
    }
  );

  console.log(_.isEqual(recase.camelCopy(snake), camel));
  console.log(_.isEqual(recase.snakeCopy(camel), snake));
}('undefined' !== typeof exports && exports || new Function('return this')()));

Currently converts between the two most common conventions (that I've seen):

• snake_case -> camelCase and _private_var -> _privateVar
• camelCase -> snake_case and _privateVar -> _private_var

npm install --save recase
bower install --save recase

Notes

Does not support CamelCaps
Use the exceptions map for inconsistent key conversions such as XMLHttpRequest -> xml_http_request.