title: Should js Cannot read property 'should' of null
body: <p>i try to use the testing tool mocha in node. Consider the following test scenario</p>
  
  <pre><code>var requirejs = require('requirejs');
  
  requirejs.config({
      //Pass the top-level main.js/index.js require
      //function to requirejs so that node modules
      //are loaded relative to the top-level JS file.
      nodeRequire: require
  });
  
  
  describe('Testing controller', function () {
  
      it('Should be pass', function (done) {
              (4).should.equal(4);
              done();
      });
  
      it('Should avoid name king', function (done) {
          requirejs(['../server/libs/validate_name'], function (validateName) {
              var err_test, accountExists_test, notAllow_test, available_test;
              validateName('anu', function (err, accountExists, notAllow, available) {
                  accountExists.should.not.be.true;
                  done();
              });
  
          });
      });
  
  });  
  </code></pre>
  
  <p>as a testing result i have got:</p>
  
  <pre><code>$ make test
  ./node_modules/.bin/mocha \
                  --reporter list
  
    . Testing controller Should be pass: 0ms
    1) Testing controller Should avoid name anu
  
    1 passing (560 ms)
    1 failing
  
    1) Testing controller Should avoid name anu:
       Uncaught TypeError: Cannot read property 'should' of null
        at d:\townspeech\test\test.spec.js:23:30
        at d:\townspeech\server\libs\validate_name.js:31:20
        at d:\townspeech\test\test.spec.js:22:13
        at Object.context.execCb (d:\townspeech\node_modules\requirejs\bin\r.js:1869:33)
        at Object.Module.check (d:\townspeech\node_modules\requirejs\bin\r.js:1105:51)
        at Object.Module.enable (d:\townspeech\node_modules\requirejs\bin\r.js:1376:22)
        at Object.Module.init (d:\townspeech\node_modules\requirejs\bin\r.js:1013:26)
        at null._onTimeout (d:\townspeech\node_modules\requirejs\bin\r.js:1646:36)
        at Timer.listOnTimeout [as ontimeout] (timers.js:110:15)
  
  
  
  make: *** [test] Error 1
  </code></pre>
  
  <p>The first pass without any complication but the second, it seems like, that could not attach module shouldjs. Why?</p>