02
Sat, Nov
2 New Articles

Test-Driven PHP Development

Web Languages
Typography
  • Smaller Small Medium Big Bigger
  • Default Helvetica Segoe Georgia Times

It's a new way of looking at an old problem.

 

Editor's note: This article is an excerpt from the new book Advanced Guide to PHP on IBM i.

 

Have you ever run into a situation where you built something or made a change somewhere only to have it break something else? If your answer is no, wait until you graduate and get a job. It is bound to happen, and sometimes it will happen with catastrophic effects.

 

Part of the problem is that we do not often test our applications very well. Yes, we press refresh and maybe use a debugger, but do we have a system for testing?

 

But beyond using a testing system, we must go a little deeper. To best use our testing system, we have to build a testable application. A testable application is generally more complicated than the typical PHP application. However, a testable application pays for itself exponentially because it lets us repeatedly test all parts of our application to verify that they are working properly from start to finish.

 

Test-driven development is the practice of building out an application based on tests, rather than building it in a fluid manner. The way we naturally build applications is that we have a problem, we figure out how to solve it, we build the application, and then we test it. Test-driven development flips that process around. Instead of initially building out the application, we build the tests first and then write our code to pass the tests. It sounds a little counterintuitive, because all through our schooling years, the last thing we did before going to the graduation party was be tested. However, building our tests at the outset provides a lot of benefits.

 

First, it forces us to think of how we intend to use the functionality that we are creating. Second, if we are building our tests before building out the application, we are more likely to consider the required range of inputs, making us more likely to test edge conditions. This testing will lead to more stable software. Third, it makes us more productive. Unit testing has been shown both in studies and in real life to make developers more productive overall, and it is one of the few practices that have virtually no downside.

 

Some might claim that because you must now write both test and actual program code, you are becoming less productive. Although this might seem true at first glance, in practice it is often not the case. When writing unit tests, you are testing individual pieces of functionality. With traditional debugging, you are trying to coax the browser into performing a certain action, whether or not it wants to. And though you might be writing more code, you are writing code that is intended to verify that the function is doing what it is supposed to be doing.

 

Unit testing can be a complex subject to cover, but even a basic understanding of it can pay for itself. I will explain only the basics of performing unit testing here. For a more in-depth treatment of the subjects, complete books are available that provide a deeper guide into how to do unit testing.

 

PHPUnit

 

By far, the most popular PHP unit testing software is PHPUnit. It is maintained by Sebastian Bergman, and you can it download at

www.phpunit.de. PHPUnit is also included in your copy of Zend Studio.

 

Generally, tests are created in a separate directory from the application to prevent them from being deployed along with the application. You can, of course, put the test files alongside your class structure and remove any unwanted tests as part of your deployment process. But it is usually easier to disallow a single directory than to hope that your pattern-matching packaging process excludes all your test files.

 

Your tests’ structure should generally follow the structure of the items you are testing. So say you have a class called My\Class. The files related to it should be as follows:

 

/lib

     /My

           /Address.php

/tests

     /My

           /AddressTest.php

 

One practice you can use in some scenarios is to build out your class structure first and stub out the methods that you will be using. Consider this class:

 

namespace My;

 

class Address

{

 

     public function setState($state)

     {

     }

 

     public function getState()

     {

     }

 

}

 

This example defines the method that the class will use but does not add any functionality to it. So you can open the PHPUnit test case window in Zend Studio and have Studio create the test class for you (Figure 7.1).

 

Figure 7.1: Creating a test class in the PHPUnit test case window

 

Truth be told, Zend Studio creates a relatively ugly file. So let’s clean that file up a little:

 

use My\Address;

 

class AddressTest extends PHPUnit_Framework_TestCase {

 

     /**

       *

       * @var Address

       */

     private $Address;

 

     protected function setUp() {

           parent::setUp ();

           $this->Address = new Address(/* parameters */);

     }

 

     public function testSetState() {

           // TODO Auto-generated AddressTest->testSetState()

           $this->markTestIncomplete ( "setState test not implemented" );

 

           $this->Address->setState(/* parameters */);

     }

}

 

What is missing in this code? It is require_once calls to the individual class you are testing along with the unit testing code. When I create a new unit test, I remove the require_once calls. I also delete a lot of boilerplate comments and other things. But to load the classes, you must first install an autoloader.

 

To set this up, you define a bootstrap file. Often, the bootstrap will be a PHP file in the root of the test directory. The PHP file will be called before the test run to set up the environment. One thing you do in that file is bootstrap the tests with an autoloader:

 

set_include_path(

     get_include_path()

     . PATH_SEPARATOR . realpath( __DIR__ . '/../lib')

     . PATH_SEPARATOR . realpath( __DIR__)

);

 

spl_autoload_register(function($class) {

     if (strpos($class, '\\') !== false) {

           $class = str_replace('\\', '/', $class);

     } else if (strpos($class, '_') !== false) {

           $class = str_replace('_', '/', $class);

     }

 

     $filename = $class . '.php';

 

     include $filename;

});

 

This bootstrap file can contain any functionality required to prepare the system for a test. Here, you needed only an autoloader and to set the include path. But in some cases, you might have to set a database connection or change a web service URL to a debug service.

 

You still have a problem, though. PHPUnit does not know where the bootstrap is. Luckily, you can configure PHPUnit with this information (and much more). PHPUnit will look for a file called phpunit.xml, which can contain various configuration options to modify how it works. Following is an example phpunit.xml file from the PHPUnit manual:

 

<phpunit backupGlobals="true"

         backupStaticAttributes="false"

         <!--bootstrap="/path/to/bootstrap.php"-->

         cacheTokens="false"

         colors="false"

         convertErrorsToExceptions="true"

         convertNoticesToExceptions="true"

         convertWarningsToExceptions="true"

         forceCoversAnnotation="false"

         mapTestClassNameToCoveredClassName="false"

         printerClass="PHPUnit_TextUI_ResultPrinter"

         <!--printerFile="/path/to/ResultPrinter.php"-->

         processIsolation="false"

         stopOnError="false"

         stopOnFailure="false"

         stopOnIncomplete="false"

         stopOnSkipped="false"

         testSuiteLoaderClass="PHPUnit_Runner_StandardTestSuiteLoader"

         <!--testSuiteLoaderFile="/path/to/StandardTestSuiteLoader.php"-->

         strict="false"

         verbose="false">

<!-- ... -->

</phpunit>

 

For your purposes, you need only one attribute set:

 

<phpunit

     bootstrap="bootstrap.php">

</phpunit>

 

With that, you are ready to go.

 

Editor's note: To learn more about using PHPUnit in Zend Studio for test-driven development, see Chapter 7 of Advanced Guide to PHP on IBM i.

 

Kevin Schroeder

Kevin Schroeder has a memory TTL of 10 years, and so he has been working with PHP for longer than he can remember. He is a member of the Zend Certification Advisory Board and is a Magento Certified Developer Plus. He has spoken at numerous conferences, including ZendCon, where he was twice the MC. When his head isn’t in code (if code is poetry, then it is Vogon poetry), Kevin is writing music, having been a guitarist since hair bands were cool (and having survived their welcomed demise). He has recorded two albums, Coronal Loop Safari and Loudness Wars. Kevin’s wisdom is dispensed to his loyal followers on Twitter at @kpschrade and on his blog at www.eschrade.com, where he speaks in the first person.


MC Press books written by Kevin Schroeder available now on the MC Press Bookstore.

Advanced Guide to PHP on IBM i Advanced Guide to PHP on IBM i
Take your PHP knowledge to the next level with this indispensable guide.
List Price $79.95

Now On Sale

The IBM i Programmer’s Guide to PHP The IBM i Programmer’s Guide to PHP
Get to know the PHP programming language and how it can--and should--be deployed on IBM i.
List Price $79.95

Now On Sale

You Want to Do What with PHP? You Want to Do What with PHP?
This book for the creative and the curious explores what’s possible with PHP.
List Price $49.95

Now On Sale

BLOG COMMENTS POWERED BY DISQUS

LATEST COMMENTS

Support MC Press Online

$

Book Reviews

Resource Center

  • SB Profound WC 5536 Have you been wondering about Node.js? Our free Node.js Webinar Series takes you from total beginner to creating a fully-functional IBM i Node.js business application. You can find Part 1 here. In Part 2 of our free Node.js Webinar Series, Brian May teaches you the different tooling options available for writing code, debugging, and using Git for version control. Brian will briefly discuss the different tools available, and demonstrate his preferred setup for Node development on IBM i or any platform. Attend this webinar to learn:

  • SB Profound WP 5539More than ever, there is a demand for IT to deliver innovation. Your IBM i has been an essential part of your business operations for years. However, your organization may struggle to maintain the current system and implement new projects. The thousands of customers we've worked with and surveyed state that expectations regarding the digital footprint and vision of the company are not aligned with the current IT environment.

  • SB HelpSystems ROBOT Generic IBM announced the E1080 servers using the latest Power10 processor in September 2021. The most powerful processor from IBM to date, Power10 is designed to handle the demands of doing business in today’s high-tech atmosphere, including running cloud applications, supporting big data, and managing AI workloads. But what does Power10 mean for your data center? In this recorded webinar, IBMers Dan Sundt and Dylan Boday join IBM Power Champion Tom Huntington for a discussion on why Power10 technology is the right strategic investment if you run IBM i, AIX, or Linux. In this action-packed hour, Tom will share trends from the IBM i and AIX user communities while Dan and Dylan dive into the tech specs for key hardware, including:

  • Magic MarkTRY the one package that solves all your document design and printing challenges on all your platforms. Produce bar code labels, electronic forms, ad hoc reports, and RFID tags – without programming! MarkMagic is the only document design and print solution that combines report writing, WYSIWYG label and forms design, and conditional printing in one integrated product. Make sure your data survives when catastrophe hits. Request your trial now!  Request Now.

  • SB HelpSystems ROBOT GenericForms of ransomware has been around for over 30 years, and with more and more organizations suffering attacks each year, it continues to endure. What has made ransomware such a durable threat and what is the best way to combat it? In order to prevent ransomware, organizations must first understand how it works.

  • SB HelpSystems ROBOT GenericIT security is a top priority for businesses around the world, but most IBM i pros don’t know where to begin—and most cybersecurity experts don’t know IBM i. In this session, Robin Tatam explores the business impact of lax IBM i security, the top vulnerabilities putting IBM i at risk, and the steps you can take to protect your organization. If you’re looking to avoid unexpected downtime or corrupted data, you don’t want to miss this session.

  • SB HelpSystems ROBOT GenericCan you trust all of your users all of the time? A typical end user receives 16 malicious emails each month, but only 17 percent of these phishing campaigns are reported to IT. Once an attack is underway, most organizations won’t discover the breach until six months later. A staggering amount of damage can occur in that time. Despite these risks, 93 percent of organizations are leaving their IBM i systems vulnerable to cybercrime. In this on-demand webinar, IBM i security experts Robin Tatam and Sandi Moore will reveal:

  • FORTRA Disaster protection is vital to every business. Yet, it often consists of patched together procedures that are prone to error. From automatic backups to data encryption to media management, Robot automates the routine (yet often complex) tasks of iSeries backup and recovery, saving you time and money and making the process safer and more reliable. Automate your backups with the Robot Backup and Recovery Solution. Key features include:

  • FORTRAManaging messages on your IBM i can be more than a full-time job if you have to do it manually. Messages need a response and resources must be monitored—often over multiple systems and across platforms. How can you be sure you won’t miss important system events? Automate your message center with the Robot Message Management Solution. Key features include:

  • FORTRAThe thought of printing, distributing, and storing iSeries reports manually may reduce you to tears. Paper and labor costs associated with report generation can spiral out of control. Mountains of paper threaten to swamp your files. Robot automates report bursting, distribution, bundling, and archiving, and offers secure, selective online report viewing. Manage your reports with the Robot Report Management Solution. Key features include:

  • FORTRAFor over 30 years, Robot has been a leader in systems management for IBM i. With batch job creation and scheduling at its core, the Robot Job Scheduling Solution reduces the opportunity for human error and helps you maintain service levels, automating even the biggest, most complex runbooks. Manage your job schedule with the Robot Job Scheduling Solution. Key features include:

  • LANSA Business users want new applications now. Market and regulatory pressures require faster application updates and delivery into production. Your IBM i developers may be approaching retirement, and you see no sure way to fill their positions with experienced developers. In addition, you may be caught between maintaining your existing applications and the uncertainty of moving to something new.

  • LANSAWhen it comes to creating your business applications, there are hundreds of coding platforms and programming languages to choose from. These options range from very complex traditional programming languages to Low-Code platforms where sometimes no traditional coding experience is needed. Download our whitepaper, The Power of Writing Code in a Low-Code Solution, and:

  • LANSASupply Chain is becoming increasingly complex and unpredictable. From raw materials for manufacturing to food supply chains, the journey from source to production to delivery to consumers is marred with inefficiencies, manual processes, shortages, recalls, counterfeits, and scandals. In this webinar, we discuss how:

  • The MC Resource Centers bring you the widest selection of white papers, trial software, and on-demand webcasts for you to choose from. >> Review the list of White Papers, Trial Software or On-Demand Webcast at the MC Press Resource Center. >> Add the items to yru Cart and complet he checkout process and submit

  • Profound Logic Have you been wondering about Node.js? Our free Node.js Webinar Series takes you from total beginner to creating a fully-functional IBM i Node.js business application.

  • SB Profound WC 5536Join us for this hour-long webcast that will explore:

  • Fortra IT managers hoping to find new IBM i talent are discovering that the pool of experienced RPG programmers and operators or administrators with intimate knowledge of the operating system and the applications that run on it is small. This begs the question: How will you manage the platform that supports such a big part of your business? This guide offers strategies and software suggestions to help you plan IT staffing and resources and smooth the transition after your AS/400 talent retires. Read on to learn: