gistfile1.js

/*
This Vows test suite produces the following spec output with vows 0.5.1 and
node  0.2.1.

    ♢ Emitter

      A NonEmitter does not inherit from EventEmitter
        ✓ and can be tested

    ✗ Errored » Emitter: An Emitter inherits from EventEmitter ∙ not fired!
    ✗ Errored » 1 honored ∙ 1 errored ∙ 1 dropped
*/

var assert = require('assert'),
    events = require('events'),
    vows   = require('vows');
    
function Emitter () {}
Emitter.prototype = new events.EventEmitter();

function NonEmitter () {}

vows.describe('Inheriting from EventEmitter').addBatch({
  'An Emitter': {
    'inherits from EventEmitter': {
      topic: function () {
        return new Emitter();
      },
      
      'but cannot be tested': function (topic) {
        // this will never run
        assert.instanceOf(topic, Emitter);
      }
    }
  },
  
  'A NonEmitter': {
    'does not inherit from EventEmitter': {
      topic: function () {
        return new NonEmitter();
      },
      
      'and can be tested': function (topic) {
        assert.instanceOf(topic, NonEmitter);
      }
    }
  }
}).export(module);