vows_test.js

var vows = require('vows'),
    assert = require('assert'),
    EventEmitter = require('events').EventEmitter,
    myEventEmitter = new EventEmitter()

var A = function(){}

// Create a Test Suite
vows.describe('Testing and EventEmitter').addBatch({
    'when the topic is a regular object':{
        topic: new A(),
        'the test gets executed' : function(topic){
            assert.isNotNull(topic)
        }
    },
    'when the topic is an EventEmitter': {
        topic: myEventEmitter,
        'The test is never executed': function (topic) { /*not fired!*/
            assert.isNotNull(topic);
        }
    }
}).run();