reverting a JSON rewire fails

[otusweb]

The following test passes if I use 2.1.5, but fails with 2.3. I'm unsure if i'm doing something wrong or not.

var assert = require("assert");
var should = require('should');
var rewire = require('rewire');
var sinon = require('sinon');

var user = rewire('../user');

describe('user', function(){
    describe('#buildNumber', function(){
        it('should return the value contained in the field "build"', function(){
            var rewireRevert = user.__set__({JSON : {
            "parse": function()
            {
                return {"build":"4"};
            }}});

            var buildNumber = user.buildNumber()
            should(buildNumber).be.ok;
            buildNumber.should.be.eql("4");

            //reset the user object to its original state
            rewireRevert();
            })
        it('should not fail when trying to get the version from the package.json', function(){
            var buildNumber = user.buildNumber()
            should(buildNumber).be.ok;
        })
    })
})

The code being tested:

var http = require('http');
var util = require('util');
var fs = require('fs');

function buildNumber()
{
    var packageVersion = JSON.parse(fs.readFileSync(__dirname + '/package.json', 'utf8')).build;

    //extract the "major" version
    return packageVersion;
}

The error returned:

user #buildNumber should return the value contained in the field "build":
     TypeError: undefined is not a function
      at __set__ (/Users/otusweb/Documents/elektra-liveshare/user.js:149:81)
      at /Users/otusweb/Documents/elektra-liveshare/user.js:178:17
      at Context.<anonymous> (/Users/otusweb/Documents/elektra-liveshare/test/user.test.js:22:4)
      at callFn (/usr/local/lib/node_modules/mocha/lib/runnable.js:251:21)
      at Test.Runnable.run (/usr/local/lib/node_modules/mocha/lib/runnable.js:244:7)
      at Runner.runTest (/usr/local/lib/node_modules/mocha/lib/runner.js:374:10)
      at /usr/local/lib/node_modules/mocha/lib/runner.js:452:12
      at next (/usr/local/lib/node_modules/mocha/lib/runner.js:299:14)
      at /usr/local/lib/node_modules/mocha/lib/runner.js:309:7
      at next (/usr/local/lib/node_modules/mocha/lib/runner.js:248:23)
      at Immediate._onImmediate (/usr/local/lib/node_modules/mocha/lib/runner.js:276:5)
      at processImmediate [as _immediateCallback] (timers.js:358:17)

[jhnns]

Rewire was using JSON.stringify. Your mock made the original JSON.stringify unaccessible for rewire.