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Chapter 7 [ 307 ] Thanks to the way the phpunit executable works, it is straightforward to execute subsets of all the tests you have created. If you give the path to an individual test class, only that class will be executed. The following command line call to phpunit, for example, will only execute the tests in the MultipleTest class. DirkMachine$ phpunit tests/Search/String/BoyerMoore/MultipleTest In contrast, if you direct phpunit to a directory, it will traverse all sub-directories and execute any test le it nds. Thus, the following command line results in all tests in classes MultipleTest, ResultCountTest, and Sequential to be executed. DirkMachine$ phpunit tests/Search/String There are also two alternative ways of organizing and grouping tests. First you can dene groupings in an XML le that you then pass to the phpunit executable as an option. Second, you can extend the PHPUnit_Framework_TestSuite class provided by PHPUnit. You can add any group of individual tests to a test suite. This approach has the additional advantage that PHPUnit_Framework_TestSuite provides methods to allow sharing of xtures across test classes (more about xtures shortly). For more details on how to use the XML or class-dened test suite, please consult the excellent PHPUnit manual. Our rst unit test Now that we know about the basic class structure of a unit test and how to use assertions, let's put that knowledge to work and create our rst basic unit test. classes/BoyerMooreStringSearchTest.php <?php require_once 'PHPUnit/Framework.php'; require_once(‘ /interfaces/StringSearchable.php'); require_once(‘ /classes/BoyerMooreStringSearch.php'); // test class are named after the class they test // and extend PHPUnit_Framework_TestCase class BoyerMooreStringSearchTest extends PHPUnit_Framework_TestCase { // methods are individual test and start with the string "test" public function testNumberOfMatches() { $poem = <<<POEM Forgetting your coffee spreading on our flannel, Your lipstick grinning on our coat, So gaily in love's unbreakable heaven Download from Wow! eBook www.WoweBook.com Testing [ 308 ] Our souls on glory of spilt bourbon float. Be with me, darling, early and late. Smash glasses— I will study wry music for your sake. For should your hands drop white and empty All the toys of the world would break. POEM; // create an instance of the search class $bm = new BoyerMooreStringSearch(); // execute the search using our algorithm $bm->search(‘our', $poem); // assert that the algorithm found the correct // number of substrings in the buffer $this->assertEquals(8, $bm->getResultsCount(), ‘The algorithm did find the correct number of matches.'); } } ?> We start by requiring the denitions of the class and interface we will be testing, StringSearchable and BoyerMooreStringSearch; as well as the PHPUnit class we are extending, PHPUnit_Framework_TestCase. The unit test class we are creating, BoyerMooreStringSearchTest, is named after the class that we are testing. The only difference is that it has "Test" appended to the class name. Our test class extends PHPUnit_Framework_TestCase because that is how we are leveraging all the goodies of the PHPUnit framework. The actual test is performed in method testNumberOfMatches(), which will be invoked automatically when we ask PHPUnit to execute our test class. The only requirement is that the method name starts with "test." The test itself is pretty straightforward. We dene a variable $poem which we will be searching for the occurrence of a substring. We are using the assertion assertEquals() to compare the number of matches reported by the class we are testing to the number of matches we know to be correct, namely eight. Download from Wow! eBook www.WoweBook.com Chapter 7 [ 309 ] That's it! Now, let's run this test from the command line. Assuming that the phpunit executable is in your path, you type the following command and observe the output. PHPUnit starts out by identifying itself, its author, and the version that is running. The single dot on the next line represents a successfully executed unit test. In particular, the assert statement in our testNumberOfMatches() method turned out to be true. If the assert had failed, the dot would have been replaced by a letter "F" for failure. PHPUnit would also provide us with some details about which test failed and display the corresponding error message. Temporarily modifying our test to expect a different number of results, we can force the unit test to fail. The corrsponding output is as follows: Extended test class features Having a test class with a single test is not quite in the spirit of unit testing. Our goal is to create enough tests to cover most or all of the scenarios our code is likely to encounter in production use. In this section, we will work towards that goal by adding additional test methods and by using different sets of data for the tests we have created. Download from Wow! eBook www.WoweBook.com Testing [ 310 ] Fixtures One of the basic tenets of unit testing is that the environment should be exactly the same each time the test is being performed. PHPUnit gives us a pair of special methods that complement each other for exactly that purpose. The methods setUp() and tearDown() are provided to us by the PHPUnit_Framework_TestCase class we are extending and these methods are responsible for setting up the environment before and after each test is performed. The important thing to note is that setUp() is called before each test method to give you a chance to reset the environment if necessary and desired. In that sense, setUp() is different from a constructor method, which only gets called once during the lifetime of an object. To illustrate this point, take a look at the following mock unit test class. SetUpTearDownTest.php <?php require_once ‘PHPUnit/Framework.php'; class SetUpTearDownTest extends PHPUnit_Framework_TestCase { // illustrating call to setUp method protected function setUp() { echo "executing " . __FUNCTION__ . "\n"; } // first generic test method public function test1() { echo "executing " . __FUNCTION__ . " \n"; } // second generic test method public function test2() { echo "executing " . __FUNCTION__ . " \n"; } // illustrating call to tearDown method protected function tearDown() { echo "executing " . __FUNCTION__ . " \n"; } } ?> Download from Wow! eBook www.WoweBook.com Chapter 7 [ 311 ] Executing the above code doesn't perform any unit tests, but it does show us exactly the order of execution of the unit test methods and the methods that prepare and clean up the environment, setup() and teardown(). Here is what we see when executing our mock unit test class from the command line: As you can conclude from the above output, setUp() gets called twice, once before each unit test method (test1 and test2). Analogously, tearDown() also gets called twice right after each of the unit test methods have completed. Practical applications for these two methods are to set up the xture of the unit tests. In other words, you get a chance to reset the environment to exactly the state required to run the tests. Only in a controlled environment is it possible to obtain reliable results. In reality, setUp() is used much more frequently than tearDown(). You will see this as we add setUp() to our sample unit test class. We use setUp() to instantiate the class we are testing before each test. However, due to automatic garbage collection upon dereferencing objects, there is no corresponding action required of the tearDown() method. Although generally not advisable, it is possible to share xtures across different sub-classes of PHPUnit_Framework_TestCase. If you are looking to implement these kinds of global xtures, take a look at adding setUp() and tearDown() to the PHPUnit_Framework_Testsuite instead of the PHPUnit_Framework_TestCase class we have been working with up to this point. Before we add xtures to our project, let's look at another useful feature that we will be implementing at the same time. Download from Wow! eBook www.WoweBook.com Testing [ 312 ] Annotations In the context of coding, annotation are directives to the compiler, interpreter, or any other kind of parser. However, annotations take the form of phpDocumentor tags and are thus embedded in the comments of the source and don't really affect the execution of the code. PHPUnit 3.3.x, which is what I used to write this chapter, supports annotations for managing code coverage analysis (@cover, @codeCoverageIgnoreStart, and @codeCoverageIgnoreEnd), automated creation of assert-based tests (@assert), grouping of test classes (@group), marking methods as tests (@test), and marking tests as part of a scenario for behavior-driven development (@scenario). In the following section, I would like to highlight the two annotations you are most likely to use, namely data providers (@dataProvider) and exception testing (@expectedException). Data providers Data providers are a shortcut for performing what is essentially the same test, but with different test data. The idea is that the PHPUnit framework knows to execute a given test method multiple times, each time passing it different parameters to be used during the test. To let PHPUnit know where to get the data, you have to add a special phpDocumentor tag that identies the name of a public method that returns either an array or an object which implements the Iterator interface. Either way, PHPUnit is then able to iterate over the array or object and call the corresponding test method for each item returned. This may sound complicated, but a quick example illustrates the concept pretty convincingly: tests/Search/String/BoyerMoore/MultipleTest.php <?php require_once ‘PHPUnit/Framework.php'; require_once(‘interfaces/StringSearchable.php'); re- quire_once(‘classes/Search/String/BoyerMoore.php'); class MultipleTest extends PHPUnit_Framework_TestCase { protected $bm; protected function setUp() { Download from Wow! eBook www.WoweBook.com Chapter 7 [ 313 ] // create the new search class $this->bm = new BoyerMoore(); } /** * @dataProvider provider */ public function testNumberOfMatches($buffer, $substring, $matches) { // execute the search $this->bm->search($substring, $buffer); // assert that the algorithm found the correct // number of substrings in the buffer $this->assertEquals($matches, $this->bm->getResultsCount()); } // This method provides data to be used when calling // method testNumberOfMatches() public function provider() { return array( array(‘abcdeabcdabcaba', ‘abc', 3), array(<<<POEM Forgetting your coffee spreading on our flannel, Your lipstick grinning on our coat, So gaily in love's unbreakable heaven Our souls on glory of spilt bourbon float. Be with me, darling, early and late. Smash glasses— I will study wry music for your sake. For should your hands drop white and empty All the toys of the world would break. POEM , ‘our', 7) ); } } ?> Class MultipleTest performs essentially the same as did class ResultCountTest we encountered earlier in this chapter. It uses our algorithm to locate all matches for a given substring and compares the result to a value known to be correct. However, we also see some of the new features we just learned about, being implemented in this class. Download from Wow! eBook www.WoweBook.com Testing [ 314 ] First, rather than having to instantiate BoyerMooreStringSearch in the test class, we let the setUp() method take care of that for us. This way, when we add additional test methods to the class, we won't have to worry about having to obtain a reference to the object we are testing. Second, we created a provider() method that returns an array. Each array member is in turn an array itself consisting of three values: the buffer, the substring, and the number of occurrences of the substring within the buffer. The number of items in the array corresponds to the number of arguments required by method testNumberOfMatches($buffer, $substring, $matches). What this means is that testNumberOfMatches() will get called twice, once with the string "abcdeabcdabcaba" as the buffer and once with the excerpt from the poem with which we have been working. At this point, adding another buffer-substring-result count test has become trivial. All we have to do is add another three-member array to the array in the provider() method and PHPUnit will take care of the rest. Following is the output from running this unit test class. As expected, we see two dots representing two successfully executed tests (really the same test with two different sets of data). Exceptions Testing exceptions can be kind of tricky. If you code some method call or data that will cause the code being tested to throw an exception, you can then wrap that code into a try-catch-statement and let the test case fail if it never reaches the catch statement. However, PHPUnit offers a much more elegant, concise, and explicit way of testing exceptions, the @expectedException annotation. By preceding the test case with an @expectedException annotation, you can let PHPUnit know that the test case should be considered a failure unless an exception is being thrown. Since there is nothing like an example to clear up confusion, here we go. Download from Wow! eBook www.WoweBook.com Chapter 7 [ 315 ] Let's say we add the following code at the beginning of the BoyerMoore::search() method to make sure the parameters we are getting are acceptable: <?php // the rest of the class's code goes here // implement interface method // with args like needle, haystack public function search($substring, $buffer, $caseSensitive = self::CASE_SENSITIVE) { // validate input if (!is_string($substring) || strlen($substring) < 1) { throw new Exception("Substring to search for must be a string with one or more characters."); } elseif (!is_string($buffer) || strlen($buffer) < 1) { throw new Exception("Buffer through which to search must be a string with one or more characters."); } elseif (!is_bool($caseSensitive)) { throw new Exception("The third argument to function " . __FUNCTION__ . " must be a boolean."); } // the rest of the class's code goes here ?> Following is the test class that allows us to test the various scenarios where an exception might get thrown due to invalid parameters being passed to the search function. <?php require_once ‘PHPUnit/Framework.php'; require_once(‘interfaces/StringSearchable.php'); require_once(‘classes/Search/String/BoyerMoore.php'); // test class are named after the class they test // and extend PHPUnit_Framework_TestCase class ExceptionsTest extends PHPUnit_Framework_TestCase { protected $bm; protected function setUp() { // create the new search class Download from Wow! eBook www.WoweBook.com Testing [ 316 ] $this->bm = new BoyerMoore(); } /** * Testing that an exception being thrown if the buffer, * substring, or 3rd argument don't pass validation. * * @dataProvider provider * @expectedException Exception */ public function testExceptions($buffer, $substring, $caseSensitive) { // execute the search using our algorithm $this->bm->search($substring, $buffer, $caseSensitive); } // This method provides data to be used when calling // method testNumberOfMatches() public function provider() { return array( array(‘', ‘find me', BoyerMoore::CASE_SENSITIVE), // empty buffer array(null, ‘find me', BoyerMoore::CASE_SENSITIVE), // null buffer array(array(), ‘find me', BoyerMoore::CASE_SENSITIVE), // array buffer array(‘search me', ‘', BoyerMoore::CASE_SENSITIVE), // empty substring array(‘search me', null, BoyerMoore::CASE_SENSITIVE), // null substring array(‘search me', array(), BoyerMoore::CASE_SENSITIVE), // array substring array(‘search me', ‘find me', ‘whatever'), // wrong 3rd arg ); } } ?> Once again we are using a data provider to call the testExceptions() method multiple times. Since testExceptions() accepts buffer, substring, and a Boolean case-sensitive ag as arguments, we can test exceptions being thrown due to any of the three arguments not passing validation. Download from Wow! eBook www.WoweBook.com [...]... class based on our BoyerMoore class: The test code that was generated by the above command is as follows: < ?php require_once ‘PHPUnit/Framework .php' ; require_once ‘BoyerMoore .php' ; /** * Test class for BoyerMoore * Generated by PHPUnit on 2009-09-01 at 12: 45: 03 */ class BoyerMooreTest extends PHPUnit_Framework_TestCase { /** * @var BoyerMoore * @access protected */ protected $object; /** * Sets up the... see, PHPUnit generated nicely formatted object-oriented PHP code that contains placeholders for the body of the test methods It even includes some helpful phpDocumentor tags, such as @access, @var, and @todo Unimplemented and skipped tests The test class skeleton generated by PHPUnit above illustrates how to mark a test as being unimplemented By calling markTestIncomplete([$message]), you can let the PHPUnit... comes when you need them in your unit tests Following is a list of PHPUnit_Framework_TestCase subclasses and corresponding descriptions: • PHPUnit_Extensions_PerformanceTestCase allows you to limit • PHPUnit_Extensions_OutputTestCase lets you construct tests for the • PHPUnit_Extensions_Database_TestCase allows you to test database • PHPUnit_Extensions_SeleniumTestCase enables you to test your code... UnzipTask: This set of complementary tasks either creates a zip archive from a group of files or extracts files from an existing archive • PHPUnit2Task: Runs test cases or test suites using the PHPUnit2 unit test framework [ 3 38 ] Download from Wow! eBook www.WoweBook.com Chapter 8 Tasks are similar to functions in that they can take arguments We will see some examples of actual tasks as soon as we start putting... BoyerMoore .php There is even a listing of the source code with highlighting that shows which lines have been tested and which have not Here is an excerpt [ 327 ] Download from Wow! eBook www.WoweBook.com Testing For obvious reasons, the higher the percentage of lines that have been tested, the more confidence you can have in the quality of your code TestCase subclasses PHPUnit provides several subclasses of PHPUnit_Framework_TestCase... Download from Wow! eBook www.WoweBook.com Chapter 7 Asking PHPUnit to run the test class above results in the folowing output: As you can see, incomplete tests have been marked with a capital letter "I" Similarly, you can use a call to markTestSkipped([$message]) to let PHPUnit know that a given test should be considered skipped In the output of phpunit, skipped tests are indicated by a capital letter... much more closely after Ant, Java's predominant build tool, than anything else Using Phing instead of Ant has the advantage that it supports various tasks specific to PHP development Also, Phing is written in PHP, which makes it easy for a PHP developer to extend its functionality Phing is driven by targets that are defined in an XML file Targets are essentially actions that Phing can perform The XML... without being ridiculed Code coverage If you happen to also have Xdebug installed, PHPUnit can easily be made to generate code coverage data Adding the option coverage-html to the command-line execution of phpunit will result in a coverage report being generated in HTML For example, I ran the following command line: phpunit coverage-html /report tests/Search/String/BoyerMoore/ [ 326 ] Download... the fun part, of course, which is why we want to make creating unit tests at the tail end of the project as quick as possible Again, PHPUnit comes to our rescue [ 317 ] Download from Wow! eBook www.WoweBook.com Testing Using the skeleton-test command line option to phpunit, we can easily generate a bare bones test class Fleshing out an automatically generated test class is a significant time saver... expected and caught seven exceptions, which means that all seven tests passed Automation: generating tests from classes Among other useful features, PHPUnit's command-line client has one that stands out as a big time saver in my opinion Given a class, phpunit can use reflection on that class and generate the skeleton of a corresponding test class If you are thoroughly committed to test-driven development, . test. classes/BoyerMooreStringSearchTest .php < ?php require_once 'PHPUnit/Framework .php& apos;; require_once(‘ /interfaces/StringSearchable .php& apos;); require_once(‘ /classes/BoyerMooreStringSearch .php& apos;); //. convincingly: tests/Search/String/BoyerMoore/MultipleTest .php < ?php require_once ‘PHPUnit/Framework .php& apos;; require_once(‘interfaces/StringSearchable .php& apos;); re- quire_once(‘classes/Search/String/BoyerMoore .php& apos;); class. as follows: < ?php require_once ‘PHPUnit/Framework .php& apos;; require_once ‘BoyerMoore .php& apos;; /** * Test class for BoyerMoore. * Generated by PHPUnit on 2009-09-01 at 12: 45: 03. */ class