How to test that something didn't happen in JavaScript other than with setTimeout ?

foo

function Foo (emitter, expectedPerson) {
    this.waitForSomething = function(callback) {
        emitter.on('something_happened', function(person) {
            if (expectedPerson === person) {
                callback(person);
            }
        });
    };
    return this;
};

module.exports = Foo;

test

var EventEmitter = require('events').EventEmitter;
var Foo = require('./foo');

describe('Let’s test that something didn’t happen', function () {
    
    var emitter, bar, foo;
    
    beforeEach(function(){
        emitter = new EventEmitter();
        bar = 'John';
        foo = new Foo(bar, emitter);
    });
    
    it('should catch a corresponding event', function (done) {
        var callback = function(name) {
            name.should.equal(bar);
            done();
        }; // if callback is not called, there's a timeout (at least with Mocha)
        
        foo.waitForSomething(callback);
        process.nextTick(function() {
            emitter.emit('something_happened', bar);
        });
    });
    
    it('should not catch a mismatched event', function (done) {
        var timeout
        var callback = function(name) {
            clearTimeout(timeout);
            done(new Error('event should not have been caught'));
        };
        
        timeout = setTimeout(done, 50); // if callback has not been called, it's fine, test is green.
        
        foo.waitForSomething(callback);
        process.nextTick(function() {
            emitter.emit('something_happened', 'Bill'); // John is expected. Not Bill
        });
    });
});