+ /**
+ * The Assert object provides functions to test JavaScript values against
+ * known and expected results. Whenever a comparison (assertion) fails,
+ * an error is thrown.
+ *
+ * @class Assert
+ * @static
+ */
+ Y.Assert = {
+
+ /**
+ * The number of assertions performed.
+ * @property _asserts
+ * @type int
+ * @private
+ */
+ _asserts: 0,
+
+ //-------------------------------------------------------------------------
+ // Helper Methods
+ //-------------------------------------------------------------------------
+
+ /**
+ * Formats a message so that it can contain the original assertion message
+ * in addition to the custom message.
+ * @param {String} customMessage The message passed in by the developer.
+ * @param {String} defaultMessage The message created by the error by default.
+ * @return {String} The final error message, containing either or both.
+ * @protected
+ * @static
+ * @method _formatMessage
+ */
+ _formatMessage : function (customMessage, defaultMessage) {
+ var message = customMessage;
+ if (Y.Lang.isString(customMessage) && customMessage.length > 0){
+ return Y.Lang.substitute(customMessage, { message: defaultMessage });
+ } else {
+ return defaultMessage;
+ }
+ },
+
+ /**
+ * Returns the number of assertions that have been performed.
+ * @method _getCount
+ * @protected
+ * @static
+ */
+ _getCount: function(){
+ return this._asserts;
+ },
+
+ /**
+ * Increments the number of assertions that have been performed.
+ * @method _increment
+ * @protected
+ * @static
+ */
+ _increment: function(){
+ this._asserts++;
+ },
+
+ /**
+ * Resets the number of assertions that have been performed to 0.
+ * @method _reset
+ * @protected
+ * @static
+ */
+ _reset: function(){
+ this._asserts = 0;
+ },
+
+ //-------------------------------------------------------------------------
+ // Generic Assertion Methods
+ //-------------------------------------------------------------------------
+
+ /**
+ * Forces an assertion error to occur.
+ * @param {String} message (Optional) The message to display with the failure.
+ * @method fail
+ * @static
+ */
+ fail : function (message) {
+ throw new Y.Assert.Error(Y.Assert._formatMessage(message, "Test force-failed."));
+ },
+
+ //-------------------------------------------------------------------------
+ // Equality Assertion Methods
+ //-------------------------------------------------------------------------
+
+ /**
+ * Asserts that a value is equal to another. This uses the double equals sign
+ * so type cohersion may occur.
+ * @param {Object} expected The expected value.
+ * @param {Object} actual The actual value to test.
+ * @param {String} message (Optional) The message to display if the assertion fails.
+ * @method areEqual
+ * @static
+ */
+ areEqual : function (expected, actual, message) {
+ Y.Assert._increment();
+ if (expected != actual) {
+ throw new Y.Assert.ComparisonFailure(Y.Assert._formatMessage(message, "Values should be equal."), expected, actual);
+ }
+ },
+
+ /**
+ * Asserts that a value is not equal to another. This uses the double equals sign
+ * so type cohersion may occur.
+ * @param {Object} unexpected The unexpected value.
+ * @param {Object} actual The actual value to test.
+ * @param {String} message (Optional) The message to display if the assertion fails.
+ * @method areNotEqual
+ * @static
+ */
+ areNotEqual : function (unexpected, actual,
+ message) {
+ Y.Assert._increment();
+ if (unexpected == actual) {
+ throw new Y.Assert.UnexpectedValue(Y.Assert._formatMessage(message, "Values should not be equal."), unexpected);
+ }
+ },
+
+ /**
+ * Asserts that a value is not the same as another. This uses the triple equals sign
+ * so no type cohersion may occur.
+ * @param {Object} unexpected The unexpected value.
+ * @param {Object} actual The actual value to test.
+ * @param {String} message (Optional) The message to display if the assertion fails.
+ * @method areNotSame
+ * @static
+ */
+ areNotSame : function (unexpected, actual, message) {
+ Y.Assert._increment();
+ if (unexpected === actual) {
+ throw new Y.Assert.UnexpectedValue(Y.Assert._formatMessage(message, "Values should not be the same."), unexpected);
+ }
+ },
+
+ /**
+ * Asserts that a value is the same as another. This uses the triple equals sign
+ * so no type cohersion may occur.
+ * @param {Object} expected The expected value.
+ * @param {Object} actual The actual value to test.
+ * @param {String} message (Optional) The message to display if the assertion fails.
+ * @method areSame
+ * @static
+ */
+ areSame : function (expected, actual, message) {
+ Y.Assert._increment();
+ if (expected !== actual) {
+ throw new Y.Assert.ComparisonFailure(Y.Assert._formatMessage(message, "Values should be the same."), expected, actual);
+ }
+ },
+
+ //-------------------------------------------------------------------------
+ // Boolean Assertion Methods
+ //-------------------------------------------------------------------------
+
+ /**
+ * Asserts that a value is false. This uses the triple equals sign
+ * so no type cohersion may occur.
+ * @param {Object} actual The actual value to test.
+ * @param {String} message (Optional) The message to display if the assertion fails.
+ * @method isFalse
+ * @static
+ */
+ isFalse : function (actual, message) {
+ Y.Assert._increment();
+ if (false !== actual) {
+ throw new Y.Assert.ComparisonFailure(Y.Assert._formatMessage(message, "Value should be false."), false, actual);
+ }
+ },
+
+ /**
+ * Asserts that a value is true. This uses the triple equals sign
+ * so no type cohersion may occur.
+ * @param {Object} actual The actual value to test.
+ * @param {String} message (Optional) The message to display if the assertion fails.
+ * @method isTrue
+ * @static
+ */
+ isTrue : function (actual, message) {
+ Y.Assert._increment();
+ if (true !== actual) {
+ throw new Y.Assert.ComparisonFailure(Y.Assert._formatMessage(message, "Value should be true."), true, actual);
+ }
+
+ },
+
+ //-------------------------------------------------------------------------
+ // Special Value Assertion Methods
+ //-------------------------------------------------------------------------
+
+ /**
+ * Asserts that a value is not a number.
+ * @param {Object} actual The value to test.
+ * @param {String} message (Optional) The message to display if the assertion fails.
+ * @method isNaN
+ * @static
+ */
+ isNaN : function (actual, message){
+ Y.Assert._increment();
+ if (!isNaN(actual)){
+ throw new Y.Assert.ComparisonFailure(Y.Assert._formatMessage(message, "Value should be NaN."), NaN, actual);
+ }
+ },
+
+ /**
+ * Asserts that a value is not the special NaN value.
+ * @param {Object} actual The value to test.
+ * @param {String} message (Optional) The message to display if the assertion fails.
+ * @method isNotNaN
+ * @static
+ */
+ isNotNaN : function (actual, message){
+ Y.Assert._increment();
+ if (isNaN(actual)){
+ throw new Y.Assert.UnexpectedValue(Y.Assert._formatMessage(message, "Values should not be NaN."), NaN);
+ }
+ },
+
+ /**
+ * Asserts that a value is not null. This uses the triple equals sign
+ * so no type cohersion may occur.
+ * @param {Object} actual The actual value to test.
+ * @param {String} message (Optional) The message to display if the assertion fails.
+ * @method isNotNull
+ * @static
+ */
+ isNotNull : function (actual, message) {
+ Y.Assert._increment();
+ if (Y.Lang.isNull(actual)) {
+ throw new Y.Assert.UnexpectedValue(Y.Assert._formatMessage(message, "Values should not be null."), null);
+ }
+ },
+
+ /**
+ * Asserts that a value is not undefined. This uses the triple equals sign
+ * so no type cohersion may occur.
+ * @param {Object} actual The actual value to test.
+ * @param {String} message (Optional) The message to display if the assertion fails.
+ * @method isNotUndefined
+ * @static
+ */
+ isNotUndefined : function (actual, message) {
+ Y.Assert._increment();
+ if (Y.Lang.isUndefined(actual)) {
+ throw new Y.Assert.UnexpectedValue(Y.Assert._formatMessage(message, "Value should not be undefined."), undefined);
+ }
+ },
+
+ /**
+ * Asserts that a value is null. This uses the triple equals sign
+ * so no type cohersion may occur.
+ * @param {Object} actual The actual value to test.
+ * @param {String} message (Optional) The message to display if the assertion fails.
+ * @method isNull
+ * @static
+ */
+ isNull : function (actual, message) {
+ Y.Assert._increment();
+ if (!Y.Lang.isNull(actual)) {
+ throw new Y.Assert.ComparisonFailure(Y.Assert._formatMessage(message, "Value should be null."), null, actual);
+ }
+ },
+
+ /**
+ * Asserts that a value is undefined. This uses the triple equals sign
+ * so no type cohersion may occur.
+ * @param {Object} actual The actual value to test.
+ * @param {String} message (Optional) The message to display if the assertion fails.
+ * @method isUndefined
+ * @static
+ */
+ isUndefined : function (actual, message) {
+ Y.Assert._increment();
+ if (!Y.Lang.isUndefined(actual)) {
+ throw new Y.Assert.ComparisonFailure(Y.Assert._formatMessage(message, "Value should be undefined."), undefined, actual);
+ }
+ },
+
+ //--------------------------------------------------------------------------
+ // Instance Assertion Methods
+ //--------------------------------------------------------------------------
+
+ /**
+ * Asserts that a value is an array.
+ * @param {Object} actual The value to test.
+ * @param {String} message (Optional) The message to display if the assertion fails.
+ * @method isArray
+ * @static
+ */
+ isArray : function (actual, message) {
+ Y.Assert._increment();
+ if (!Y.Lang.isArray(actual)){
+ throw new Y.Assert.UnexpectedValue(Y.Assert._formatMessage(message, "Value should be an array."), actual);
+ }
+ },
+
+ /**
+ * Asserts that a value is a Boolean.
+ * @param {Object} actual The value to test.
+ * @param {String} message (Optional) The message to display if the assertion fails.
+ * @method isBoolean
+ * @static
+ */
+ isBoolean : function (actual, message) {
+ Y.Assert._increment();
+ if (!Y.Lang.isBoolean(actual)){
+ throw new Y.Assert.UnexpectedValue(Y.Assert._formatMessage(message, "Value should be a Boolean."), actual);
+ }
+ },
+
+ /**
+ * Asserts that a value is a function.
+ * @param {Object} actual The value to test.
+ * @param {String} message (Optional) The message to display if the assertion fails.
+ * @method isFunction
+ * @static
+ */
+ isFunction : function (actual, message) {
+ Y.Assert._increment();
+ if (!Y.Lang.isFunction(actual)){
+ throw new Y.Assert.UnexpectedValue(Y.Assert._formatMessage(message, "Value should be a function."), actual);
+ }
+ },
+
+ /**
+ * Asserts that a value is an instance of a particular object. This may return
+ * incorrect results when comparing objects from one frame to constructors in
+ * another frame. For best results, don't use in a cross-frame manner.
+ * @param {Function} expected The function that the object should be an instance of.
+ * @param {Object} actual The object to test.
+ * @param {String} message (Optional) The message to display if the assertion fails.
+ * @method isInstanceOf
+ * @static
+ */
+ isInstanceOf : function (expected, actual, message) {
+ Y.Assert._increment();
+ if (!(actual instanceof expected)){
+ throw new Y.Assert.ComparisonFailure(Y.Assert._formatMessage(message, "Value isn't an instance of expected type."), expected, actual);
+ }
+ },
+
+ /**
+ * Asserts that a value is a number.
+ * @param {Object} actual The value to test.
+ * @param {String} message (Optional) The message to display if the assertion fails.
+ * @method isNumber
+ * @static
+ */
+ isNumber : function (actual, message) {
+ Y.Assert._increment();
+ if (!Y.Lang.isNumber(actual)){
+ throw new Y.Assert.UnexpectedValue(Y.Assert._formatMessage(message, "Value should be a number."), actual);
+ }
+ },
+
+ /**
+ * Asserts that a value is an object.
+ * @param {Object} actual The value to test.
+ * @param {String} message (Optional) The message to display if the assertion fails.
+ * @method isObject
+ * @static
+ */
+ isObject : function (actual, message) {
+ Y.Assert._increment();
+ if (!Y.Lang.isObject(actual)){
+ throw new Y.Assert.UnexpectedValue(Y.Assert._formatMessage(message, "Value should be an object."), actual);
+ }
+ },
+
+ /**
+ * Asserts that a value is a string.
+ * @param {Object} actual The value to test.
+ * @param {String} message (Optional) The message to display if the assertion fails.
+ * @method isString
+ * @static
+ */
+ isString : function (actual, message) {
+ Y.Assert._increment();
+ if (!Y.Lang.isString(actual)){
+ throw new Y.Assert.UnexpectedValue(Y.Assert._formatMessage(message, "Value should be a string."), actual);
+ }
+ },
+
+ /**
+ * Asserts that a value is of a particular type.
+ * @param {String} expectedType The expected type of the variable.
+ * @param {Object} actualValue The actual value to test.
+ * @param {String} message (Optional) The message to display if the assertion fails.
+ * @method isTypeOf
+ * @static
+ */
+ isTypeOf : function (expectedType, actualValue, message){
+ Y.Assert._increment();
+ if (typeof actualValue != expectedType){
+ throw new Y.Assert.ComparisonFailure(Y.Assert._formatMessage(message, "Value should be of type " + expectedType + "."), expected, typeof actualValue);
+ }
+ }
+ };
+
+ /**
+ * Asserts that a given condition is true. If not, then a Y.Assert.Error object is thrown
+ * and the test fails.
+ * @method Y.assert
+ * @param {Boolean} condition The condition to test.
+ * @param {String} message The message to display if the assertion fails.
+ * @static
+ */
+ Y.assert = function(condition, message){
+ Y.Assert._increment();
+ if (!condition){
+ throw new Y.Assert.Error(Y.Assert._formatMessage(message, "Assertion failed."));
+ }
+ };
+
+ /**
+ * Forces an assertion error to occur. Shortcut for Y.Assert.fail().
+ * @method Y.fail
+ * @param {String} message (Optional) The message to display with the failure.
+ * @static
+ */
+ Y.fail = Y.Assert.fail;
+
+ //-----------------------------------------------------------------------------
+ // Assertion errors
+ //-----------------------------------------------------------------------------
+
+ /**
+ * Error is thrown whenever an assertion fails. It provides methods
+ * to more easily get at error information and also provides a base class
+ * from which more specific assertion errors can be derived.
+ *
+ * @param {String} message The message to display when the error occurs.
+ * @namespace Assert
+ * @class Error
+ * @constructor
+ */
+ Y.Assert.Error = function (message){
+
+ //call superclass
+ arguments.callee.superclass.constructor.call(this, message);
+
+ /*
+ * Error message. Must be duplicated to ensure browser receives it.
+ * @type String
+ * @property message
+ */
+ this.message = message;
+
+ /**
+ * The name of the error that occurred.
+ * @type String
+ * @property name
+ */
+ this.name = "Assert Error";
+ };
+
+ //inherit methods
+ Y.extend(Y.Assert.Error, Error, {
+
+ /**
+ * Returns a fully formatted error for an assertion failure. This should
+ * be overridden by all subclasses to provide specific information.
+ * @method getMessage
+ * @return {String} A string describing the error.
+ */
+ getMessage : function () {
+ return this.message;
+ },
+
+ /**
+ * Returns a string representation of the error.
+ * @method toString
+ * @return {String} A string representation of the error.
+ */
+ toString : function () {
+ return this.name + ": " + this.getMessage();
+ },
+
+ /**
+ * Returns a primitive value version of the error. Same as toString().
+ * @method valueOf
+ * @return {String} A primitive value version of the error.
+ */
+ valueOf : function () {
+ return this.toString();
+ }
+
+ });
+
+ /**
+ * ComparisonFailure is subclass of Error that is thrown whenever
+ * a comparison between two values fails. It provides mechanisms to retrieve
+ * both the expected and actual value.
+ *
+ * @param {String} message The message to display when the error occurs.
+ * @param {Object} expected The expected value.
+ * @param {Object} actual The actual value that caused the assertion to fail.
+ * @namespace Assert
+ * @extends Assert.Error
+ * @class ComparisonFailure
+ * @constructor
+ */
+ Y.Assert.ComparisonFailure = function (message, expected, actual){
+
+ //call superclass
+ arguments.callee.superclass.constructor.call(this, message);
+
+ /**
+ * The expected value.
+ * @type Object
+ * @property expected
+ */
+ this.expected = expected;
+
+ /**
+ * The actual value.
+ * @type Object
+ * @property actual
+ */
+ this.actual = actual;
+
+ /**
+ * The name of the error that occurred.
+ * @type String
+ * @property name
+ */
+ this.name = "ComparisonFailure";
+
+ };
+
+ //inherit methods
+ Y.extend(Y.Assert.ComparisonFailure, Y.Assert.Error, {
+
+ /**
+ * Returns a fully formatted error for an assertion failure. This message
+ * provides information about the expected and actual values.
+ * @method toString
+ * @return {String} A string describing the error.
+ */
+ getMessage : function () {
+ return this.message + "\nExpected: " + this.expected + " (" + (typeof this.expected) + ")" +
+ "\nActual: " + this.actual + " (" + (typeof this.actual) + ")";
+ }
+
+ });
+
+ /**
+ * UnexpectedValue is subclass of Error that is thrown whenever
+ * a value was unexpected in its scope. This typically means that a test
+ * was performed to determine that a value was *not* equal to a certain
+ * value.
+ *
+ * @param {String} message The message to display when the error occurs.
+ * @param {Object} unexpected The unexpected value.
+ * @namespace Assert
+ * @extends Assert.Error
+ * @class UnexpectedValue
+ * @constructor
+ */
+ Y.Assert.UnexpectedValue = function (message, unexpected){
+
+ //call superclass
+ arguments.callee.superclass.constructor.call(this, message);
+
+ /**
+ * The unexpected value.
+ * @type Object
+ * @property unexpected
+ */
+ this.unexpected = unexpected;
+
+ /**
+ * The name of the error that occurred.
+ * @type String
+ * @property name
+ */
+ this.name = "UnexpectedValue";
+
+ };
+
+ //inherit methods
+ Y.extend(Y.Assert.UnexpectedValue, Y.Assert.Error, {
+
+ /**
+ * Returns a fully formatted error for an assertion failure. The message
+ * contains information about the unexpected value that was encountered.
+ * @method getMessage
+ * @return {String} A string describing the error.
+ */
+ getMessage : function () {
+ return this.message + "\nUnexpected: " + this.unexpected + " (" + (typeof this.unexpected) + ") ";
+ }
+
+ });
+
+ /**
+ * ShouldFail is subclass of Error that is thrown whenever
+ * a test was expected to fail but did not.
+ *
+ * @param {String} message The message to display when the error occurs.
+ * @namespace Assert
+ * @extends Assert.Error
+ * @class ShouldFail
+ * @constructor
+ */
+ Y.Assert.ShouldFail = function (message){
+
+ //call superclass
+ arguments.callee.superclass.constructor.call(this, message || "This test should fail but didn't.");
+
+ /**
+ * The name of the error that occurred.
+ * @type String
+ * @property name
+ */
+ this.name = "ShouldFail";
+
+ };
+
+ //inherit methods
+ Y.extend(Y.Assert.ShouldFail, Y.Assert.Error);
+
+ /**
+ * ShouldError is subclass of Error that is thrown whenever
+ * a test is expected to throw an error but doesn't.
+ *
+ * @param {String} message The message to display when the error occurs.
+ * @namespace Assert
+ * @extends Assert.Error
+ * @class ShouldError
+ * @constructor
+ */
+ Y.Assert.ShouldError = function (message){
+
+ //call superclass
+ arguments.callee.superclass.constructor.call(this, message || "This test should have thrown an error but didn't.");
+
+ /**
+ * The name of the error that occurred.
+ * @type String
+ * @property name
+ */
+ this.name = "ShouldError";
+
+ };
+
+ //inherit methods
+ Y.extend(Y.Assert.ShouldError, Y.Assert.Error);
+
+ /**
+ * UnexpectedError is subclass of Error that is thrown whenever
+ * an error occurs within the course of a test and the test was not expected
+ * to throw an error.
+ *
+ * @param {Error} cause The unexpected error that caused this error to be
+ * thrown.
+ * @namespace Assert
+ * @extends Assert.Error
+ * @class UnexpectedError
+ * @constructor
+ */
+ Y.Assert.UnexpectedError = function (cause){
+
+ //call superclass
+ arguments.callee.superclass.constructor.call(this, "Unexpected error: " + cause.message);
+
+ /**
+ * The unexpected error that occurred.
+ * @type Error
+ * @property cause
+ */
+ this.cause = cause;
+
+ /**
+ * The name of the error that occurred.
+ * @type String
+ * @property name
+ */
+ this.name = "UnexpectedError";
+
+ /**
+ * Stack information for the error (if provided).
+ * @type String
+ * @property stack
+ */
+ this.stack = cause.stack;
+
+ };
+
+ //inherit methods
+ Y.extend(Y.Assert.UnexpectedError, Y.Assert.Error);
+
+