/**
     * Runs test suites and test cases, providing events to allowing for the
     * interpretation of test results.
     * @namespace Test
     * @module test
 * @class TestRunner
     * @static
     */
    YUITest.TestRunner = function(){
 
        /*(intentionally not documented)
         * Determines if any of the array of test groups appears
         * in the given TestRunner filter.
         * @param {Array} testGroups The array of test groups to
         *      search for.
         * @param {String} filter The TestRunner groups filter.
         */
        function inGroups(testGroups, filter){
            if (!filter.length){
                return true;
            } else {
                if (testGroups){
                    for (var i=0, len=testGroups.length; i < len; i++){
                        if (filter.indexOf("," + testGroups[i] + ",") > -1){
                            return true;
                        }
                    }
                }
                return false;
            }
        }
 
        /**
         * A node in the test tree structure. May represent a TestSuite, TestCase, or
         * test function.
         * @param {Any} testObject A TestSuite, TestCase, or the name of a test function.
         * @module test
 * @class TestNode
         * @constructor
         * @private
         */
        function TestNode(testObject){
 
            /**
             * The TestSuite, TestCase, or test function represented by this node.
             * @type {Any}
             * @property testObject
             */
            this.testObject = testObject;
 
            /**
             * Pointer to this node's first child.
             * @type TestNode
             * @property firstChild
             */
            this.firstChild = null;
 
            /**
             * Pointer to this node's last child.
             * @type TestNode
             * @property lastChild
             */
            this.lastChild = null;
 
            /**
             * Pointer to this node's parent.
             * @type TestNode
             * @property parent
             */
            this.parent = null;
 
            /**
             * Pointer to this node's next sibling.
             * @type TestNode
             * @property next
             */
            this.next = null;
 
            /**
             * Test results for this test object.
             * @type object
             * @property results
             */
            this.results = new YUITest.Results();
 
            //initialize results
            if (testObject instanceof YUITest.TestSuite){
                this.results.type = "testsuite";
                this.results.name = testObject.name;
            } else if (testObject instanceof YUITest.TestCase){
                this.results.type = "testcase";
                this.results.name = testObject.name;
            }
 
        }
 
        TestNode.prototype = {
 
            /**
             * Appends a new test object (TestSuite, TestCase, or test function name) as a child
             * of this node.
             * @param {Any} testObject A TestSuite, TestCase, or the name of a test function.
             * @method appendChild
             */
            appendChild : function (testObject){
                var node = new TestNode(testObject);
                if (this.firstChild === null){
                    this.firstChild = this.lastChild = node;
                } else {
                    this.lastChild.next = node;
                    this.lastChild = node;
                }
                node.parent = this;
                return node;
            }
        };
 
        /**
         * Runs test suites and test cases, providing events to allowing for the
         * interpretation of test results.
         * @namespace Test
         * @module test
 * @class Runner
         * @static
         */
        function TestRunner(){
 
            //inherit from EventTarget
            YUITest.EventTarget.call(this);
 
            /**
             * Suite on which to attach all TestSuites and TestCases to be run.
             * @type YUITest.TestSuite
             * @property masterSuite
             * @static
             * @private
             */
            this.masterSuite = new YUITest.TestSuite(YUITest.guid('testSuite_'));
 
            /**
             * Pointer to the current node in the test tree.
             * @type TestNode
             * @private
             * @property _cur
             * @static
             */
            this._cur = null;
 
            /**
             * Pointer to the root node in the test tree.
             * @type TestNode
             * @private
             * @property _root
             * @static
             */
            this._root = null;
 
            /**
             * Indicates if the TestRunner will log events or not.
             * @type Boolean
             * @property _log
             * @private
             * @static
             */
            this._log = true;
 
            /**
             * Indicates if the TestRunner is waiting as a result of
             * wait() being called.
             * @type Boolean
             * @property _waiting
             * @private
             * @static
             */
            this._waiting = false;
 
            /**
             * Indicates if the TestRunner is currently running tests.
             * @type Boolean
             * @private
             * @property _running
             * @static
             */
            this._running = false;
 
            /**
             * Holds copy of the results object generated when all tests are
             * complete.
             * @type Object
             * @private
             * @property _lastResults
             * @static
             */
            this._lastResults = null;
 
            /**
             * Data object that is passed around from method to method.
             * @type Object
             * @private
             * @property _data
             * @static
             */
            this._context = null;
 
            /**
             * The list of test groups to run. The list is represented
             * by a comma delimited string with commas at the start and
             * end.
             * @type String
             * @private
             * @property _groups
             * @static
             */
            this._groups = "";
 
        }
 
        TestRunner.prototype = YUITest.Util.mix(new YUITest.EventTarget(), {
 
            /**
            * If true, YUITest will not fire an error for tests with no Asserts.
            * @property _ignoreEmpty
            * @private
            * @type Boolean
            * @static
            */
            _ignoreEmpty: false,
 
            //restore prototype
            constructor: YUITest.TestRunner,
 
            //-------------------------------------------------------------------------
            // Constants
            //-------------------------------------------------------------------------
 
            /**
             * Fires when a test case is opened but before the first
             * test is executed.
             * @event testcasebegin
             * @static
             */
            TEST_CASE_BEGIN_EVENT : "testcasebegin",
 
            /**
             * Fires when all tests in a test case have been executed.
             * @event testcasecomplete
             * @static
             */
            TEST_CASE_COMPLETE_EVENT : "testcasecomplete",
 
            /**
             * Fires when a test suite is opened but before the first
             * test is executed.
             * @event testsuitebegin
             * @static
             */
            TEST_SUITE_BEGIN_EVENT : "testsuitebegin",
 
            /**
             * Fires when all test cases in a test suite have been
             * completed.
             * @event testsuitecomplete
             * @static
             */
            TEST_SUITE_COMPLETE_EVENT : "testsuitecomplete",
 
            /**
             * Fires when a test has passed.
             * @event pass
             * @static
             */
            TEST_PASS_EVENT : "pass",
 
            /**
             * Fires when a test has failed.
             * @event fail
             * @static
             */
            TEST_FAIL_EVENT : "fail",
 
            /**
             * Fires when a non-test method has an error.
             * @event error
             * @static
             */
            ERROR_EVENT : "error",
 
            /**
             * Fires when a test has been ignored.
             * @event ignore
             * @static
             */
            TEST_IGNORE_EVENT : "ignore",
 
            /**
             * Fires when all test suites and test cases have been completed.
             * @event complete
             * @static
             */
            COMPLETE_EVENT : "complete",
 
            /**
             * Fires when the run() method is called.
             * @event begin
             * @static
             */
            BEGIN_EVENT : "begin",
 
            //-------------------------------------------------------------------------
            // Test Tree-Related Methods
            //-------------------------------------------------------------------------
 
            /**
             * Adds a test case to the test tree as a child of the specified node.
             * @param {TestNode} parentNode The node to add the test case to as a child.
             * @param {Test.TestCase} testCase The test case to add.
             * @static
             * @private
             * @method _addTestCaseToTestTree
             */
           _addTestCaseToTestTree : function (parentNode, testCase){
 
                //add the test suite
                var node = parentNode.appendChild(testCase),
                    prop,
                    testName;
 
                //iterate over the items in the test case
                for (prop in testCase){
                    if ((prop.indexOf("test") === 0 || prop.indexOf(" ") > -1) && typeof testCase[prop] == "function"){
                        node.appendChild(prop);
                    }
                }
 
            },
 
            /**
             * Adds a test suite to the test tree as a child of the specified node.
             * @param {TestNode} parentNode The node to add the test suite to as a child.
             * @param {Test.TestSuite} testSuite The test suite to add.
             * @static
             * @private
             * @method _addTestSuiteToTestTree
             */
            _addTestSuiteToTestTree : function (parentNode, testSuite) {
 
                //add the test suite
                var node = parentNode.appendChild(testSuite);
 
                //iterate over the items in the master suite
                for (var i=0; i < testSuite.items.length; i++){
                    if (testSuite.items[i] instanceof YUITest.TestSuite) {
                        this._addTestSuiteToTestTree(node, testSuite.items[i]);
                    } else if (testSuite.items[i] instanceof YUITest.TestCase) {
                        this._addTestCaseToTestTree(node, testSuite.items[i]);
                    }
                }
            },
 
            /**
             * Builds the test tree based on items in the master suite. The tree is a hierarchical
             * representation of the test suites, test cases, and test functions. The resulting tree
             * is stored in _root and the pointer _cur is set to the root initially.
             * @static
             * @private
             * @method _buildTestTree
             */
            _buildTestTree : function () {
 
                this._root = new TestNode(this.masterSuite);
                //this._cur = this._root;
 
                //iterate over the items in the master suite
                for (var i=0; i < this.masterSuite.items.length; i++){
                    if (this.masterSuite.items[i] instanceof YUITest.TestSuite) {
                        this._addTestSuiteToTestTree(this._root, this.masterSuite.items[i]);
                    } else if (this.masterSuite.items[i] instanceof YUITest.TestCase) {
                        this._addTestCaseToTestTree(this._root, this.masterSuite.items[i]);
                    }
                }
 
            },
 
            //-------------------------------------------------------------------------
            // Private Methods
            //-------------------------------------------------------------------------
 
            /**
             * Handles the completion of a test object's tests. Tallies test results
             * from one level up to the next.
             * @param {TestNode} node The TestNode representing the test object.
             * @method _handleTestObjectComplete
             * @private
             */
            _handleTestObjectComplete : function (node) {
                var parentNode;
 
                if (node && (typeof node.testObject == "object")) {
                    parentNode = node.parent;
 
                    if (parentNode){
                        parentNode.results.include(node.results);
                        parentNode.results[node.testObject.name] = node.results;
                    }
 
                    if (node.testObject instanceof YUITest.TestSuite){
                        this._execNonTestMethod(node, "tearDown", false);
                        node.results.duration = (new Date()) - node._start;
                        this.fire({ type: this.TEST_SUITE_COMPLETE_EVENT, testSuite: node.testObject, results: node.results});
                    } else if (node.testObject instanceof YUITest.TestCase){
                        this._execNonTestMethod(node, "destroy", false);
                        node.results.duration = (new Date()) - node._start;
                        this.fire({ type: this.TEST_CASE_COMPLETE_EVENT, testCase: node.testObject, results: node.results});
                    }
                }
            },
 
            //-------------------------------------------------------------------------
            // Navigation Methods
            //-------------------------------------------------------------------------
 
            /**
             * Retrieves the next node in the test tree.
             * @return {TestNode} The next node in the test tree or null if the end is reached.
             * @private
             * @static
             * @method _next
             */
            _next : function () {
 
                if (this._cur === null){
                    this._cur = this._root;
                } else if (this._cur.firstChild) {
                    this._cur = this._cur.firstChild;
                } else if (this._cur.next) {
                    this._cur = this._cur.next;
                } else {
                    while (this._cur && !this._cur.next && this._cur !== this._root){
                        this._handleTestObjectComplete(this._cur);
                        this._cur = this._cur.parent;
                    }
 
                    this._handleTestObjectComplete(this._cur);
 
                    if (this._cur == this._root){
                        this._cur.results.type = "report";
                        this._cur.results.timestamp = (new Date()).toLocaleString();
                        this._cur.results.duration = (new Date()) - this._cur._start;
                        this._lastResults = this._cur.results;
                        this._running = false;
                        this.fire({ type: this.COMPLETE_EVENT, results: this._lastResults});
                        this._cur = null;
                    } else if (this._cur) {
                        this._cur = this._cur.next;
                    }
                }
 
                return this._cur;
            },
 
            /**
             * Executes a non-test method (init, setUp, tearDown, destroy)
             * and traps an errors. If an error occurs, an error event is
             * fired.
             * @param {Object} node The test node in the testing tree.
             * @param {String} methodName The name of the method to execute.
             * @param {Boolean} allowAsync Determines if the method can be called asynchronously.
             * @return {Boolean} True if an async method was called, false if not.
             * @method _execNonTestMethod
             * @private
             */
            _execNonTestMethod: function(node, methodName, allowAsync){
                var testObject = node.testObject,
                    event = { type: this.ERROR_EVENT };
                try {
                    if (allowAsync && testObject["async:" + methodName]){
                        testObject["async:" + methodName](this._context);
                        return true;
                    } else {
                        testObject[methodName](this._context);
                    }
                } catch (ex){
                    node.results.errors++;
                    event.error = ex;
                    event.methodName = methodName;
                    if (testObject instanceof YUITest.TestCase){
                        event.testCase = testObject;
                    } else {
                        event.testSuite = testSuite;
                    }
 
                    this.fire(event);
                }
 
                return false;
            },
 
            /**
             * Runs a test case or test suite, returning the results.
             * @param {Test.TestCase|YUITest.TestSuite} testObject The test case or test suite to run.
             * @return {Object} Results of the execution with properties passed, failed, and total.
             * @private
             * @method _run
             * @static
             */
            _run : function () {
 
                //flag to indicate if the TestRunner should wait before continuing
                var shouldWait = false;
 
                //get the next test node
                var node = this._next();
 
                if (node !== null) {
 
                    //set flag to say the testrunner is running
                    this._running = true;
 
                    //eliminate last results
                    this._lastResult = null;
 
                    var testObject = node.testObject;
 
                    //figure out what to do
                    if (typeof testObject == "object" && testObject !== null){
                        if (testObject instanceof YUITest.TestSuite){
                            this.fire({ type: this.TEST_SUITE_BEGIN_EVENT, testSuite: testObject });
                            node._start = new Date();
                            this._execNonTestMethod(node, "setUp" ,false);
                        } else if (testObject instanceof YUITest.TestCase){
                            this.fire({ type: this.TEST_CASE_BEGIN_EVENT, testCase: testObject });
                            node._start = new Date();
 
                            //regular or async init
                            /*try {
                                if (testObject["async:init"]){
                                    testObject["async:init"](this._context);
                                    return;
                                } else {
                                    testObject.init(this._context);
                                }
                            } catch (ex){
                                node.results.errors++;
                                this.fire({ type: this.ERROR_EVENT, error: ex, testCase: testObject, methodName: "init" });
                            }*/
                            if(this._execNonTestMethod(node, "init", true)){
                                return;
                            }
                        }
 
                        //some environments don't support setTimeout
                        if (typeof setTimeout != "undefined"){
                            setTimeout(function(){
                                YUITest.TestRunner._run();
                            }, 0);
                        } else {
                            this._run();
                        }
                    } else {
                        this._runTest(node);
                    }
 
                }
            },
 
            _resumeTest : function (segment) {
 
                //get relevant information
                var node = this._cur;
 
                //we know there's no more waiting now
                this._waiting = false;
 
                //if there's no node, it probably means a wait() was called after resume()
                if (!node){
                    //TODO: Handle in some way?
                    //console.log("wait() called after resume()");
                    //this.fire("error", { testCase: "(unknown)", test: "(unknown)", error: new Error("wait() called after resume()")} );
                    return;
                }
 
                var testName = node.testObject;
                var testCase = node.parent.testObject;
 
                //cancel other waits if available
                if (testCase.__yui_wait){
                    clearTimeout(testCase.__yui_wait);
                    delete testCase.__yui_wait;
                }
 
                //get the "should" test cases
                var shouldFail = testName.indexOf("fail:") === 0 ||
                                    (testCase._should.fail || {})[testName];
                var shouldError = (testCase._should.error || {})[testName];
 
                //variable to hold whether or not the test failed
                var failed = false;
                var error = null;
 
                //try the test
                try {
 
                    //run the test
                    segment.call(testCase, this._context);
 
                    //if the test hasn't already failed and doesn't have any asserts...
                    if(YUITest.Assert._getCount() == 0 && !this._ignoreEmpty){
                        throw new YUITest.AssertionError("Test has no asserts.");
                    }
                    //if it should fail, and it got here, then it's a fail because it didn't
                     else if (shouldFail){
                        error = new YUITest.ShouldFail();
                        failed = true;
                    } else if (shouldError){
                        error = new YUITest.ShouldError();
                        failed = true;
                    }
 
                } catch (thrown){
 
                    //cancel any pending waits, the test already failed
                    if (testCase.__yui_wait){
                        clearTimeout(testCase.__yui_wait);
                        delete testCase.__yui_wait;
                    }
 
                    //figure out what type of error it was
                    if (thrown instanceof YUITest.AssertionError) {
                        if (!shouldFail){
                            error = thrown;
                            failed = true;
                        }
                    } else if (thrown instanceof YUITest.Wait){
 
                        if (typeof thrown.segment == "function"){
                            if (typeof thrown.delay == "number"){
 
                                //some environments don't support setTimeout
                                if (typeof setTimeout != "undefined"){
                                    testCase.__yui_wait = setTimeout(function(){
                                        YUITest.TestRunner._resumeTest(thrown.segment);
                                    }, thrown.delay);
                                    this._waiting = true;
                                } else {
                                    throw new Error("Asynchronous tests not supported in this environment.");
                                }
                            }
                        }
 
                        return;
 
                    } else {
                        //first check to see if it should error
                        if (!shouldError) {
                            error = new YUITest.UnexpectedError(thrown);
                            failed = true;
                        } else {
                            //check to see what type of data we have
                            if (typeof shouldError == "string"){
 
                                //if it's a string, check the error message
                                if (thrown.message != shouldError){
                                    error = new YUITest.UnexpectedError(thrown);
                                    failed = true;
                                }
                            } else if (typeof shouldError == "function"){
 
                                //if it's a function, see if the error is an instance of it
                                if (!(thrown instanceof shouldError)){
                                    error = new YUITest.UnexpectedError(thrown);
                                    failed = true;
                                }
 
                            } else if (typeof shouldError == "object" && shouldError !== null){
 
                                //if it's an object, check the instance and message
                                if (!(thrown instanceof shouldError.constructor) ||
                                        thrown.message != shouldError.message){
                                    error = new YUITest.UnexpectedError(thrown);
                                    failed = true;
                                }
 
                            }
 
                        }
                    }
 
                }
 
                //fire appropriate event
                if (failed) {
                    this.fire({ type: this.TEST_FAIL_EVENT, testCase: testCase, testName: testName, error: error });
                } else {
                    this.fire({ type: this.TEST_PASS_EVENT, testCase: testCase, testName: testName });
                }
 
                //run the tear down
                this._execNonTestMethod(node.parent, "tearDown", false);
 
                //reset the assert count
                YUITest.Assert._reset();
 
                //calculate duration
                var duration = (new Date()) - node._start;
 
                //update results
                node.parent.results[testName] = {
                    result: failed ? "fail" : "pass",
                    message: error ? error.getMessage() : "Test passed",
                    type: "test",
                    name: testName,
                    duration: duration
                };
 
                if (failed){
                    node.parent.results.failed++;
                } else {
                    node.parent.results.passed++;
                }
                node.parent.results.total++;
 
                //set timeout not supported in all environments
                if (typeof setTimeout != "undefined"){
                    setTimeout(function(){
                        YUITest.TestRunner._run();
                    }, 0);
                } else {
                    this._run();
                }
 
            },
 
            /**
             * Handles an error as if it occurred within the currently executing
             * test. This is for mock methods that may be called asynchronously
             * and therefore out of the scope of the TestRunner. Previously, this
             * error would bubble up to the browser. Now, this method is used
             * to tell TestRunner about the error. This should never be called
             * by anyplace other than the Mock object.
             * @param {Error} error The error object.
             * @method _handleError
             * @private
             * @static
             */
            _handleError: function(error){
 
                if (this._waiting){
                    this._resumeTest(function(){
                        throw error;
                    });
                } else {
                    throw error;
                }
 
            },
 
            /**
             * Runs a single test based on the data provided in the node.
             * @method _runTest
             * @param {TestNode} node The TestNode representing the test to run.
             * @static
             * @private
             */
            _runTest : function (node) {
 
                //get relevant information
                var testName = node.testObject,
                    testCase = node.parent.testObject,
                    test = testCase[testName],
 
                    //get the "should" test cases
                    shouldIgnore = testName.indexOf("ignore:") === 0 ||
                                    !inGroups(testCase.groups, this._groups) ||
                                    (testCase._should.ignore || {})[testName];   //deprecated
 
                //figure out if the test should be ignored or not
                if (shouldIgnore){
 
                    //update results
                    node.parent.results[testName] = {
                        result: "ignore",
                        message: "Test ignored",
                        type: "test",
                        name: testName.indexOf("ignore:") === 0 ? testName.substring(7) : testName
                    };
 
                    node.parent.results.ignored++;
                    node.parent.results.total++;
 
                    this.fire({ type: this.TEST_IGNORE_EVENT,  testCase: testCase, testName: testName });
 
                    //some environments don't support setTimeout
                    if (typeof setTimeout != "undefined"){
                        setTimeout(function(){
                            YUITest.TestRunner._run();
                        }, 0);
                    } else {
                        this._run();
                    }
 
                } else {
 
                    //mark the start time
                    node._start = new Date();
 
                    //run the setup
                    this._execNonTestMethod(node.parent, "setUp", false);
 
                    //now call the body of the test
                    this._resumeTest(test);
                }
 
            },
 
            //-------------------------------------------------------------------------
            // Misc Methods
            //-------------------------------------------------------------------------
 
            /**
             * Retrieves the name of the current result set.
             * @return {String} The name of the result set.
             * @method getName
             */
            getName: function(){
                return this.masterSuite.name;
            },
 
            /**
             * The name assigned to the master suite of the TestRunner. This is the name
             * that is output as the root's name when results are retrieved.
             * @param {String} name The name of the result set.
             * @method setName
             */
            setName: function(name){
                this.masterSuite.name = name;
            },
 
            //-------------------------------------------------------------------------
            // Public Methods
            //-------------------------------------------------------------------------
 
            /**
             * Adds a test suite or test case to the list of test objects to run.
             * @param testObject Either a TestCase or a TestSuite that should be run.
             * @method add
             * @static
             */
            add : function (testObject) {
                this.masterSuite.add(testObject);
                return this;
            },
 
            /**
             * Removes all test objects from the runner.
             * @method clear
             * @static
             */
            clear : function () {
                this.masterSuite = new YUITest.TestSuite(YUITest.guid('testSuite_'));
            },
 
            /**
             * Indicates if the TestRunner is waiting for a test to resume
             * @return {Boolean} True if the TestRunner is waiting, false if not.
             * @method isWaiting
             * @static
             */
            isWaiting: function() {
                return this._waiting;
            },
 
            /**
             * Indicates that the TestRunner is busy running tests and therefore can't
             * be stopped and results cannot be gathered.
             * @return {Boolean} True if the TestRunner is running, false if not.
             * @method isRunning
             */
            isRunning: function(){
                return this._running;
            },
 
            /**
             * Returns the last complete results set from the TestRunner. Null is returned
             * if the TestRunner is running or no tests have been run.
             * @param {Function} format (Optional) A test format to return the results in.
             * @return {Object|String} Either the results object or, if a test format is
             *      passed as the argument, a string representing the results in a specific
             *      format.
             * @method getResults
             */
            getResults: function(format){
                if (!this._running && this._lastResults){
                    if (typeof format == "function"){
                        return format(this._lastResults);
                    } else {
                        return this._lastResults;
                    }
                } else {
                    return null;
                }
            },
 
            /**
             * Returns the coverage report for the files that have been executed.
             * This returns only coverage information for files that have been
             * instrumented using YUI Test Coverage and only those that were run
             * in the same pass.
             * @param {Function} format (Optional) A coverage format to return results in.
             * @return {Object|String} Either the coverage object or, if a coverage
             *      format is specified, a string representing the results in that format.
             * @method getCoverage
             */
            getCoverage: function(format) {
                var covObject = null;
                if (typeof _yuitest_coverage === "object") {
                    covObject = _yuitest_coverage;
                }
                if (typeof __coverage__ === "object") {
                    covObject = __coverage__;
                }
                if (!this._running && typeof covObject == "object"){
                    if (typeof format == "function") {
                        return format(covObject);
                    } else {
                        return covObject;
                    }
                } else {
                    return null;
                }
            },
 
            /**
             * Used to continue processing when a method marked with
             * "async:" is executed. This should not be used in test
             * methods, only in init(). Each argument is a string, and
             * when the returned function is executed, the arguments
             * are assigned to the context data object using the string
             * as the key name (value is the argument itself).
             * @private
             * @return {Function} A callback function.
             * @method callback
             */
            callback: function(){
                var names   = arguments,
                    data    = this._context,
                    that    = this;
 
                return function(){
                    for (var i=0; i < arguments.length; i++){
                        data[names[i]] = arguments[i];
                    }
                    that._run();
                };
            },
 
            /**
             * Resumes the TestRunner after wait() was called.
             * @param {Function} segment The function to run as the rest
             *      of the haulted test.
             * @method resume
             * @static
             */
            resume : function (segment) {
                if (this._waiting){
                    this._resumeTest(segment || function(){});
                } else {
                    throw new Error("resume() called without wait().");
                }
            },
 
            /**
             * Runs the test suite.
             * @param {Object|Boolean} options (Optional) Options for the runner:
             *      <code>oldMode</code> indicates the TestRunner should work in the YUI <= 2.8 way
             *      of internally managing test suites. <code>groups</code> is an array
             *      of test groups indicating which tests to run.
             * @method run
             * @static
             */
            run : function (options) {
 
                options = options || {};
 
                //pointer to runner to avoid scope issues
                var runner  = YUITest.TestRunner,
                    oldMode = options.oldMode;
 
 
                //if there's only one suite on the masterSuite, move it up
                if (!oldMode && this.masterSuite.items.length == 1 && this.masterSuite.items[0] instanceof YUITest.TestSuite){
                    this.masterSuite = this.masterSuite.items[0];
                }
 
                //determine if there are any groups to filter on
                runner._groups = (options.groups instanceof Array) ? "," + options.groups.join(",") + "," : "";
 
                //initialize the runner
                runner._buildTestTree();
                runner._context = {};
                runner._root._start = new Date();
 
                //fire the begin event
                runner.fire(runner.BEGIN_EVENT);
 
                //begin the testing
                runner._run();
            }
        });
 
        return new TestRunner();
 
    }();