This example shows how to create an asynchronous test with the YUI Test framework for testing browser-based JavaScript code.
A Y.Test.Case
object is created with a test that waits for a
few seconds before continuing. The Y.Test.Runner
is then used to run the tests once the page has loaded.
Asynchronous Test Example
This example begins by creating a namespace:
Y.namespace("example.test");
This namespace serves as the core object upon which others will be added (to prevent creating global objects).
Creating the TestCase
The first step is to create a new Y.Test.Case
object called AsyncTestCase
.
To do so, using the Y.Test.Case
constructor and pass in an object literal containing information about the tests to be run:
Y.example.test.AsyncTestCase = new Y.Test.Case({ //name of the test case - if not provided, one is auto-generated name : "Asynchronous Tests", //--------------------------------------------------------------------- // setUp and tearDown methods - optional //--------------------------------------------------------------------- /* * Sets up data that is needed by each test. */ setUp : function () { this.data = { name: "test", year: 2007, beta: true }; }, /* * Cleans up everything that was created by setUp(). */ tearDown : function () { delete this.data; }, //--------------------------------------------------------------------- // Test methods - names must begin with "test" //--------------------------------------------------------------------- testWait : function (){ var Assert = Y.Assert; //do some assertions now Assert.isTrue(this.data.beta); Assert.isNumber(this.data.year); //wait five seconds and do some more this.wait(function(){ Assert.isString(this.data.name); }, 5000); } });
The object literal passed into the constructor contains two different sections. The first section contains the name
property,
which is used to determine which Y.Test.Case
is being executed. A name is necessary, so one is generated if it isn't specified.
Next, the setUp()
and tearDown()
methods are included. The setUp()
method is used in a Y.Test.Case
to set up data that may be needed for tests to be completed. This method is called immediately before each test is executed. For this example,
setUp()
creates a data object. The tearDown()
is responsible for undoing what was done in setUp()
. It is
run immediately after each test is run and, in this case, deletes the data object that was created by setUp
. These methods are optional.
The second section contains the actual tests to be run. The only test is testWait()
, which demonstrates using
the wait()
method to delay test execution. There are two arguments passed in: a function to run once the test resumes
and the number of milliseconds to wait before running this function (same basic format as setTimeout()
). When
the test resumes, the function is executed in the context of the Y.Test.Case
object, meaning that it still has
access to all of the same data as the test that called wait()
, including properties and methods on the Y.Test.Case
itself. This example shows the anonymous function using both the Y.Assert
object and the data
property
of the Y.Test.Case
.
Running the tests
With all of the tests defined, the last step is to run them:
//create the console (new Y.Test.Console({ verbose : true, newestOnTop : false })).render('#testLogger'); //add the test suite to the runner's queue Y.Test.Runner.add(Y.example.test.AsyncTestCase); //run the tests Y.Test.Runner.run();
Before running the tests, it's necessary to create a Y.Test.Console
object to display the results (otherwise the tests would run
but you wouldn't see the results). After that, the Y.Test.Runner
is loaded with the Y.Test.Case
object by calling
add()
(any number of Y.Test.Case
and TestSuite
objects can be added to a TestRunner
,
this example only adds one for simplicity). The very last step is to call run()
, which begins executing the tests in its
queue and displays the results in the Y.Test.Console
.
Complete Example Source
<div id="testLogger"></div> <script> YUI().use('node', 'test-console', 'test',function (Y) { Y.namespace("example.test"); Y.example.test.AsyncTestCase = new Y.Test.Case({ //name of the test case - if not provided, one is auto-generated name : "Asynchronous Tests", //--------------------------------------------------------------------- // setUp and tearDown methods - optional //--------------------------------------------------------------------- /* * Sets up data that is needed by each test. */ setUp : function () { this.data = { name: "test", year: 2007, beta: true }; }, /* * Cleans up everything that was created by setUp(). */ tearDown : function () { delete this.data; }, //--------------------------------------------------------------------- // Test methods - names must begin with "test" //--------------------------------------------------------------------- testWait : function (){ var Assert = Y.Assert; //do some assertions now Assert.isTrue(this.data.beta); Assert.isNumber(this.data.year); //wait five seconds and do some more this.wait(function(){ Assert.isString(this.data.name); }, 5000); } }); //create the console (new Y.Test.Console({ newestOnTop : false, filters: { pass: true, fail: true } })).render('#testLogger'); Y.Test.Runner.add(Y.example.test.AsyncTestCase); //run the tests Y.Test.Runner.run(); }); </script>