simple test

(function(){

    var YUITest = require('yuitest');
    
    var testCase = new YUITest.TestCase({
    
        'this should work': function() {
          YUITest.Assert.isTrue(6 === 6);
        }

    });
    
    YUITest.TestRunner.add(testCase);
    YUITest.TestRunner.run();
}());

Running this via

$ yuitest test123

returns:
Total tests: 0, Failures: 0, Skipped: 0, Time: 0.001 seconds