Quality In PHP Projects Beyond Unittests

Quality in PHP projects beyond Unittests International PHP Conference 2008 October 30th 2008 | Thorsten Rinne

Introduction ❙ Thorsten Rinne ❙ 31 years old ❙ Senior Developer and Team Lead at Mayflower GmbH ❙ Reporting applications ❙ Rating applications ❙ PHP consulting for QA and migration problems ❙ PHP software development since 1999 ❙ Founder and main developer of open source FAQ management software phpMyFAQ since 2001 ❙ Zend Certified Engineer (PHP 5) Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 2

Introduction ❙ Warm up ❙ Quality Criterias ❙ Quality Metrics ❙ Testing ❙ PHP Source Code Quality ❙ Questions and answers Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 3

Who are you? ❙ What's your profession? ❙ Software company or agency? ❙ What's your team size? ❙ Who develops using Unittests? ❙ Who uses QA supporting tools? ❙ What's your test coverage? ❙ Even for legacy code? :-) Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 4

Quality Criterias Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 5

Quality criterias: Understandability ❙ Availability of documentation ❙ Good documentation quality ❙ Complexity of software ❙ Code commenting and formatting ❙ Understandable naming Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 6

Quality criterias: Completeness ❙ Everything is already there ❙ Your application is fully implemented ❙ No mockups or temporary solutions left ❙ External interfaces are usable ❙ All needed data is available Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 7

Quality criterias: Conciseness ❙ No unneeded, overlong documentation ❙ Especially auto-generated documentation ❙ No unused libraries ❙ No dead code ❙ No duplicate code ❙ No code inside loops that could be outside Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 8

Quality criterias: Portability ❙ Easy to configure in new environments ❙ Few OS and webserver dependencies ❙ Few, documented version dependencies ❙ Language version ❙ Database version ❙ External libraries ❙ Able to survice environment updates Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 9

Quality criterias: Consistency ❙ Predictability ❙ Directory paths and filenames ❙ Class and method names ❙ Variable and constant names ❙ Documentation style and language ❙ Coding style Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 10

Quality criterias: Maintainability ❙ Easy to install and easy to upgrade ❙ Tests and debug logs to help to locate bugs ❙ Few dependencies hiding the bug ❙ No complex dependencies or effects on the platform ❙ Easy to understand and navigate source code Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 11

Quality criterias: Testability ❙ Known acceptence criteria ❙ Adequate separation of concerns ❙ Easy to use interfaces for tests ❙ No limiting dependencies Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 12

Quality criterias: Reliability ❙ The criteria formerly known as „robustness“ ❙ Fault tolerance ❙ Graceful degradation ❙ Exception handling exists ❙ Is method input checked? Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 13

Quality criterias: Usability ❙ Learnability: Easyness of first time usage ❙ Efficiency: Overall speed of usage per task ❙ Memorabilty: Time to re-establish usage knowledge after absence ❙ Errors: Frequency of usage errors ❙ Satisfaction: Fun to use the software Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 14

Quality Metrics Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 15

Quality Metrics: Defect Density Metrics ❙ Code-based metric ❙ Defects per KSSI (1000 shipped source instructions) for product quality ❙ Defects per KCSI (1000 changed source instructions) for development quality ❙ (Hard to measure) ❙ Statistic needed ❙ easier for products Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 16

Quality Metrics: Customer Problem Metrics ❙ PUM: Problems per user month ❙ Defects per month / number of installations ❙ Maintainance metric: Number of bugs closed / number of bugs arrived ❙ The customer does not care how big or how complicated the software is :-) Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 17

Quality Metrics: Customer Satisfaction Metrics ❙ You only get them by survey ❙ for ❙ Functionality ❙ Usability ❙ Reliability ❙ Performance ❙ Maintainability ❙ Service ❙ Levels: Very Satisfied, Satisfied, Neutral, Dissatisfied, Very Dissatisfied Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 18

Quality Metrics: When are bugs detected? ❙ Number of pre-release bugs found while testing ❙ Number of post-release bugs ❙ found by customer ❙ found by testing Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 19

Quality Metrics: How are defects fixed? ❙ Average Time to fix a bug ❙ Average Time for bugfix release ❙ that‘s the time relevant for the customer ❙ Average engineering hours / fixed defect Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 20

Quality Metrics: Defect Impact ❙ was the defect visible to the user? ❙ has a monetary transaction been touched? ❙ has sensitive data been touched? ❙ are there security implications? ❙ has there been a marketing/image effect ❙ did data / user work get lost? Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 21

Quality Metrics: Testing Efficiency ❙ Found bugs before release / found bugs post release ❙ Found bugs by qa team / found bugs by customer ❙ Number of bugs found by QA Team / time Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 22

„We do PHPUnit!“ !== Testing Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 23

Unit Testing ❙ For PHP: PHPUnit or SimpleTest ❙ Focussing on testing a single unit of work ❙ solves depencies using mock objects ❙ should not depend on database ❙ perfect and easy to automate ❙ Reason for all refactoring Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 24

Acceptence Testing ❙ originally user acceptance testing ❙ one of the final testing stages ❙ change to automated black box testing in agile environments ❙ used to test user stories ❙ often contractual requirement Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 25

SOA / Service Testing ❙ in multi-tier environments every service can have several consumers ❙ black box test for the service api ❙ can easily be automated ❙ a lot of tools for SOAP Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 26

Integration Testing ❙ tests the application with all parts ❙ needed for multi-tier applications ❙ tests the interaction paths ❙ intersection with load testing: user simulation Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 27

Load Testing ❙ Simulates high load situations ❙ to detect the current platform abilities ❙ to detect resource bottlenecks (Database, CPU, Network) ❙ to detect concurreny bottlenecks (locking jams, caching effects) ❙ Scalability testing: scale up or scale out? Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 28

Usability Testing ❙ How does the user work with the application? ❙ Efficiency: time to fulfill a basic task ❙ Accuracy: how many mistakes happened? ❙ Recall: does the user recall the usage after a period of time? ❙ Emotional response: does the user feel lucky, confident or stressed about the task? Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 29

Regression Testing ❙ originally: if you find a bug, fix it and write a test ❙ PHP itself does it ❙ now often written by the test team to assure the expected default behavior ❙ modern: automated test generation Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 30

Security Testing ❙ Blackbox: Penetration Test done by external auditor just before release ❙ Graybox: using tools like fuzzers and scanners before release or while development ❙ Whitebox: internal or external source code audit, static code analysis while development Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 31

A lot more ... ❙ Compability testing for maintainability ❙ Volume testing for bigger amounts of data ❙ Stress testing for degrade and failover processes ❙ Installation testing for maintenance ❙ Recovery testing to check recovery behavior Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 32

Documentation ❙ We have different forms of documentation: ❙ Inline documentation ❙ API documentation ❙ Developer documentation ❙ Security documentation ❙ Administration documentation ❙ End-user documentation Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 34

Coding Style / Formatting ❙ Coding style is defined in the developer documentation ❙ All developers have to write their code formatted in the given coding style ❙ Can be checked by CodeSniffer tools ❙ Coding style should be based on your main used libraries ❙ If you build your application on top of the Zend Framework, use the ZF coding style ❙ With IDEs like Eclipse you can format old code autpmatically Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 35

Naming Conventions ❙ Naming conventions are very important ❙ NonamespacesbeforePHP5.3 ❙ Easier for __autoload() ❙ Examples ❙ Class names: ❙ class HTML_Template_ITX2 ❙ Directory: include/PEAR2/HTML/Template/ITX2.php ❙ Function names in camel caps: ❙ public function blockExists($blockname) Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 36

Code Complexity ❙ Complexity costs time and money if you don‘t need it ❙ KISS principle: Keep it simple and stupid ❙ Complexity checks by CodeSniffer metrics ❙ Important for good code coverage and unittests ❙ Examples ❙ Too high number of linearly independent paths through a program's source code ❙ Too long class and method names ❙ Too many properties ❙ Too many parameters ❙ Too many methods inside a class Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 37

Anti Patterns ❙ An antipattern is a design pattern that appears obvious but is ineffective or far from optimal in practice ❙ Examples ❙ Unnecessary abstraction ❙ God objects ❙ Spaghetti code ❙ Too short or too long variable names Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 38

Anti Pattern Examples ❙ if(<EXPR>) {<empty>} ❙ if(<EXPR>) {<EXPR>} else {<empty>} ❙ try(<EXPR>) {<empty>} ❙ try(<EXPR>) {<EXPR>} catch(Exception $e) {<empty>} ❙ define('SOME_NAME', $var) ❙ include[_once]|require[_once]|readfile| virtual|file_get_contents|fopen|file| mysql_query($_GET|$_POST|$_REQUEST) Quality in PHP projects beyond Unittests © MAYFLOWER GmbH 2008 39

Thank you very much! Thorsten Rinne Mayflower GmbH Mannhardtstr. 6 80538 München +49 (89) 24 20 54 - 31 thorsten.rinne@mayflower.de

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Quality In PHP Projects Beyond Unittests

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Quality In PHP Projects Beyond Unittests — Presentation Transcript