title: 'TypeError: is not a function' in Node.js
body: <p>I'm getting the error while running the following code in Node.js</p>
  
  <pre><code>var assert = require('assert');
  var request = require('request');
  var index = require('./index');
  it('verify javascript function', function(done) {
      var v2 = index.AddNumbers(5, 6);
      assert.equal(11, v2);
      done();
  });
  </code></pre>
  
  <p>The <code>index.js</code> file contain the following code:</p>
  
  <pre><code>function AddNumbers(a,b){
      return a+b;
  }
  </code></pre>
  
  <p>What am I doing wrong?</p>