Testing and MXUnit

1. Testing and MXUnit In ColdFusion By DenardSpringle July 2011, NVCFUG

2. What is MXUnit? • A testing framework for use in testing components (cfc’s) • One piece of an integrated development methodology (e.g. Hudson, Ant and MXUnit) • One tool in the Test Driven developers toolkit • One tool in the Object-Oriented developers toolkit • It is not useful for testing non-component templates or output • HTML • Javascript/Ajax • CSS • Etc.

3. Test Environment • A well organized SDLC environment includes: • One or more development servers where code is developed and debugged by developers. • One or more testing servers where code is tested using MXUnit (and/or other test frameworks), and is used by QA for regression testing. • One or more production servers where fully tested and certified code is released. • Dedicated testing servers prevent: • Developers from crashing the test server • Production being used to test code which mayleave datasources in an unknown state • Writing complex extended DAO testing frameworks

4. Installing MXUnit • Download the latest MXUnit Framework. • Unzip into webroot • Test the install: http://myserver/mxunit/index.cfm • Webroot is the root directory of the website you are testing.

5. Anatomy of a Test Case Part One • The TestCase file is a component (a .cfc file) • The filename either starts or ends with "Test" • The component extends mxunit.framework.TestCase or extends a component that eventually extends mxunit.framework.TestCase • The TestCase can contain setUp() and tearDown() functions that will run prior to and aftereach and everytest • The TestCase can contain beforeTests() and afterTests() functions that will be run oncebefore and onceafteralltests

6. Anatomy of a Test Case Part Two • The TestCase can contain any number of public methods. Those public methods are considered tests regardless of their name, and MXUnit will run them as tests. • Any private methods are not considered tests and will not be run by MXUnit • Failures will be recorded as failures; errors as errors; and successes as successes • Inside of your tests, you make assertions on the results of functions that you call on your component under test

7. Anatomy of a Test Case Part Three • To very quickly get started, you can run the test by loading it in the browser and suffixing it with "?method=runTestRemote", like so: http://localhost/tests/MyTest.cfc?method=runTestRemote • Example TestCase:

8. Test Driven Development (TDD) By Kent Beck • Write the test first • Watch the test fail • Write the component • Watch the test pass • Test Driven Development allows you to write your test cases before you begin development. • One caveat to TDD is the components you developare only as good as the tests you write. So getgood at writing tests if you want to use TDD.

9. Assertions as·sert - to demonstrate the existence of • The core of unit testing, i.e. Assertions, are simple: • You assert something, and if that assertion does not result in your expectation, the test fails. • All code AFTER a failed assertion will NOT execute. • Repeat: A failed assertion means the end of that test. • This is why it's best practice to not load each test function with lots of assertions. • A single failed assertion means that any subsequent assertions in a test will not execute and thus you won't know if those assertions indicate further problems in your code. • In other words, one assertion per test function is strongly suggested

10. Built-In Assertions • assertTrue(boolean condition [,String message]) • assertTrue is one of the two "bread and butter" assertions in any testing framework. The philosophy is simple: you assert something to be true; if it's not, the test fails • assertEquals (expected,actual[, String message]) • assertEquals is the other core assertion. Here, you're asserting that some actual result equals some expected result. This could be two numbers, two strings, two structs, whatever. For now, MXUnit follows the JUnit pattern of using a single assertEquals to compare any type of data. • assertFalse(booleancondition [, String message])

11. Built-In Assertions • assertSame (obj1,obj2 [,String message]) • Used to determine if the obj1 and obj2 refer to the same instance.Note that arrays in Adobe ColdFusion are passed by value, so, this will always fail for arrays. • assertNotSame (obj1,obj2 [,String message]) • Used to determine if the obj1 and obj2 do not refer to the same instance.Note that arrays in Adobe ColdFusion are passed by value, so, this will always pass for arrays.

12. MXUnitAssertion Extensions These are extensions to the base set of assertions and are specific to ColdFusion. • assertIsTypeOf (component obj, String type) • Determines if obj is of type. type needs to be fully qualified (i.e. ‘core.beans.User’). • assertIsXMLDoc (any xml [, String message]) • Determines if xml is a valid XML DOM object. • assertIsArray (any obj1) • Determines if the obj1 is a valid array. • assertIsDefined*(any obj1) • Determines if the obj1 has been defined in the available scope.

13. MXUnitAssertion Extensions • assertIsEmpty (any obj1) • Determines if the obj1 is a 0 length string or NULL equivalent. • assertIsEmptyArray (any obj1,[String message]) • Determines if the obj1 is an array with no elements. • assertIsEmptyQuery(any obj1,[String message]) • Determines if the obj1 is a query with no rows. • assertIsEmptyStruct (any obj1,[String message]) • Determines if the obj1 is a struct with no keys or values.

14. MXUnitAssertion Extensions • assertIsQuery (any q) • Determines if q is a valid ColdFusion query. • assertIsStruct (any obj) • Determines if obj is a valid ColdFusion structure.

15. Custom Assertions Provides an easy way to add custom assertions to your tests without having to change the mxunit core. • The steps for creating your custom assertion are as follows: • Write a test for your assertion • Write the assertion • Decide how you want to load it: Always or only on selected tests. • Assertion Rules: • Your assertion will need to throw mxunit.exception.AssertionFailedError or use an existing assertion that throws this exception. • If you want to have optional first or last parameter message, you will need to call normalizeArguments(arguments) in your code.

16. Data Driven Testing With MXUnitdataproviders • Data driven testing allows you to execute tests with a wide variety of input data. This can make creating and executing certain kinds of tests efficient and very powerful. Essentially, you provide a reference to a collection of data and MXUnit will iterate over that data and execute the test for each item in the collection. • Data Providers • Array • Query • List • Excel/CSV • Iterator • mxunit:dataprovider=“<data provider>”

17. DAO Test Adapter Pattern A Test Adapter Pattern for DAO Testing • Transactions • The goal is to have a way to execute code that utilizes database logic (inserts, updates, deletes, etc.), test the results of the code, and set the state of the database back to a known state. • Leveraging transactions is one way to achieve this. • The process is to execute code and after assertions, roll back any transactions. Sounds simple ... it is and it isn't. • ColdFusion is limited with transaction handling - you cannot have nested transactions and you need to use the <cftransaction ...> tag.

18. DAO Test Adapter Pattern A Test Adapter Pattern for DAO Testing • Write the test first • Extend the DAO component under test to DAOTestAdapter, or similar • Refactorour DAO component: extracting the database logic to a package access method with no transaction handling • Code this packageaccessed method within the transaction block of the public DAO method • Create a method in DAOTestAdapter that overrides the DAO method under test and calls the package access method, but rolls back the transaction no matter what • Run the test. The expected behavior is that data is inserted into the db, and the method returns true

19. Assertion Patterns **The terms here are taken from the outstanding book "Test-Driven" by LasseKoskela. • Resulting-State Assertion • The resulting-state assertion tests data. It says "I'm doing something to my object that will change that object's data, or 'state'. I'm going to test that the resulting state of my object is as I expect". A simple example is the common "bank account" or "transaction" example: You have two accounts, you transfer $20 from one account to another, and you test that the first account is 20 bucks shorter and the second account has that 20 bucks. • Different instances, same data • The different-instances, same-data pattern is common in DAO testing. Essentially, we're asserting that two objects are different instances but contain the same data. In MXUnit, you can test for "different instance" by using the assertNotSame() assertion.

20. Assertion Patterns • Guard Assertion • The guard assertion is simply a slight variant on the resulting state assertion; typically, the difference is that toward the top of the test, before you get into the "guts" of your assertion(s), you check the object for some condition that you want to ensure exists before proceeding with the meat of your tests. Think of it as "If this condition isn't true, I want to fail right now because the rest of the tests don't matter". Usually the "guard" is just a simple assertion for equality, often to check that a "default" condition exists. • Interaction Assertion • With interaction assertions, we're testing to make sure an object and a collaborator worked together as we expected. A great example of an interaction is a "bean" style object, like perhaps a "User", and the DAO for that object, like a UserDAO

21. Assertion Patterns • "Delta" Assertion • Sometimes you can't assert an absolute equality (like "My list is now 5 elements long"). Sometimes, you have to assert equality relative to some previous state. Imagine you're hooking into some scheduling mechanism, for example. We don't know exactly what getTotalScheduled() will return at any given test run. Maybe it's 1. Maybe it's 30. Who knows. What we want to test is that when we schedule one additional thing, our scheduler's "totalScheduled" count increases by 1. • This type of assertion, where we compare the state right before and right after performing some task, is called "delta", or difference, assertion.

22. Creating and Running a TestSuite A TestSuite is a collection of tests that logically fit together. • MXUnit was built to make it as easy as possible to create tests and test suites. • The steps for creating and running a TestSuite are: • Create a ColdFusion page to run the suite • Create a TestSuite object • Tell the TestSuite what tests to add • run() the TestSuite • Print the output • Run the suite in your web browser

23. Additional Resources • http://www.mxunit.org • Test Driven Development: By Example • Test Driven: TDD and Acceptance TDD for Java Developers • ColdFusion 9 Developer Tutorial – Chapter 14 • Marc Esher’sMXUnit Blog