Assert.js revision cd4f0c50c6a7faa3fd8e38236929bb9b37bc11b7
/**
* 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);