Clean Application Development

A presentation at Bulgaria PHP in September 2015 in Sofia, Bulgaria by Adam Culp

Clean Application Development Adam Culp @adamculp

Clean Application Development ● About me ● OSS Contributor ● PHP Certified ● Zend Certification Advisory Board ● PHP-Fig voting member (IBM i Toolkit) ● Consultant at Zend Technologies ● Organizer SoFloPHP (South Florida) ● Organizer SunshinePHP (Miami) ● Long distance (ultra) runner ● Photography Enthusiast ● Page  2 Judo Black Belt Instructor

Clean Application Development ● About me ● OSS Contributor ● PHP Certified ● Zend Certification Advisory Board ● PHP-Fig voting member (IBM i Toolkit) ● Consultant at Zend Technologies ● Organizer SoFloPHP (South Florida) ● Organizer SunshinePHP (Miami) ● Long distance (ultra) runner ● Photography Enthusiast ● Page  3 I am the Judo Black Belt Instructor PHP Ninja!!!

Clean Application Development – Iteration ●I love iteration! ● Evolution. ● Learning to walk. ● Training to run. ● Evading project managers. ● Clean development. Page  4

Clean Application Development – Learning ● Clean application development cannot be taught in 45 minutes ● Practice, Practice, Practice. ● Leave the code better than you found it. ● Always watch for new techniques. ● No “silver bullet“. Page  5

Clean Application Development – Resources ●A great resource on code quality. Clean Code By Robert C. Martin Page  6

Clean Application Development – Causes of bad… ● Disasters happen, resulting in bad… ● It’s easy ● Short deadlines ● Boss ● Laziness ● Lack of “how-to“ ● Come back and clean later ● We are the cause! Page  7

Clean Application Development – Typical Scenario ● Bad things starts innocently ● Hire a new professional/developer ● Clean slate, no expectations ● Start ● a new project Initial output is quick and easy, setting expectation ● Slows down over time ● Complexity increases ● Domino effect Page  8

Clean Application Development – Defend the code ● Our responsibility to say “NO“ ● Managers job = defend schedule and features ● Our job = defend the code ● Managers respect realistic reasons and explanations Page  9

Clean Application Development – We are judged ● Others judge us on our code ● We are @authors. ● 75% of time reading code ● Others read our code also ● And they talk about it! ● How developers talk about us = “CRED“ And they talk about it! Page  10

Clean Application Development – Result of bad code ● Side-effects of bad code: ● Wasted Time ● Bugs ● Excessive debugging ● Procrastination ● Missed deadlines ● Technical debt ● Financial losses Page  11

Clean Application Development – The aftermath ● How we typically react to a dirty application: ● Padded estimates ● Developers Hide ● Become defensive ● Blame others/requirements ● Add developers ● Rewrite! Page  12

Clean Application Development – Rewrite problems ● The problem with a rewrite: ● Development team split, old/new ● Legacy application enhanced ● New application Scope creep ● Is it done yet? ● Ends with more bad code! Page  13

Clean Application Development – Resources ● Learn to Refactor. Refactoring By Martin Fowler https://github.com/adamculp/refactoring101 Page  14 Refactoring 101 By Adam Culp https://refactoring101.com

Clean Application Development – Common sense ● With all of these problems, clean applications makes sense ● Shortens development time. ● On-boarding of developers easier. ● Less bugs. ● Happier end-users. ● Predictable schedules. ● It’s the professional thing to do. Page  15

Clean Application Development – Coding standards ● Coding Standards save time ● Gives direction ● PHP Framework Interoperability Group (https://www.php-fig.org). ● Standard NOT important ● ● Unless it‘s public code ● Choose one ● Stick with it Consistency is key Page  16

Clean Application Development – Clear names ● Names ● should be clear Functions and variables should tell a story. Bad $elapsed; $createdDays; $modifiedDays; $age; Page  17 Good $elapsedTimeInDays; $daysSinceCreation; $daysSinceModified; $fileAgeInDays;

Clean Application Development – No confusion ● Shy ● away from variations of the same name To ensure names are different enough to portray difference. What is the difference between these? $product $productInfo $productData $productDescription Page  18

Clean Application Development – Bad characters ● Certain characters are hard to understand Bad Lower case L Uppercase O (oh) Uppercase I (eye) Page  19

Clean Application Development – Name grammar ● Technical names help developers who actually read the code. ● Non-technical ● Class terms for client documentation. names should be nouns ● Describe. ● Ex. - Customer, Account, Product, Company. ● Method names should be verbs ● Action. ● Ex. - getCustomer, closeAccount, updateProduct, addCompany. ● Pick a set of keywords and stick with them. ● Page  20 Ex. - fetch, get, add, update, remove, delete

Clean Application Development – Clean code ● More ● ● on Clean Code Functions: ● Short ● Single purpose ● As expected ● Well named Recognizing bad doesn’t mean we know how to make good ● We know a good/bad song, but are not song writers ● Clean code = caring developer ● Does not require many comments Page  21

Clean Application Development – Code comments ● Comments can also be a bad “smell“ ● Comments are often used to cover up bad code. ● Code should be self-documenting Page  22

Clean Application Development – Smells of bad code ● How to spot bad code (smells) ● Incomplete error handling ● Memory leaks ● Race conditions ● Inconsistent naming convention (class, function, variable) ● Inconsistent coding standard ● Un-initialized variables ● Code lacks clear purpose ● Functions do too much (more than one thing) ● Globals used ● Too many comments in the code ● Notices, Warnings, Fatal Errors Page  23

Clean Application Development – Code sniffer ● Let PHP CodeSniffer detect bad smells ● Set rules to detect if coding standard is not followed ● Run during commits in version control ● IDE integration Page  24

Clean Application Development – Peer code reviews ● Peer code review great learning tool ● Peers help train each other on strong points. ● Fresh set of eyes. ● Builds better teams. Page  25

Clean Application Development – Design Patterns ● Standard and quick solutions to common coding problems ● Provide standard ways of dealing with common code problems. ● “Guide to PHP Design Patterns“ by Jason Sweat. ● “Design Patterns, Elements of Reusable Object-Oriented Software“ by Gang of four Page  26

Clean Application Development – Frameworks ● Frameworks ● help keep things in line $evil = ‘roll-your-own’ ● Knowledge transfer ● Onboarding ● Insecure ● Allows our code to be lighter, simpler ● Does heavy lifting ● Most modern frameworks are: ● ● MVC ● Service driven ● Middleware STICK TO IT!!! Page  27

Clean Application Development – Clear architecture ● We can tell pretty simply this “looks“ like a library. (bookshelves, computers, book categories) Page  28

Clean Application Development – Obvious purpose ● These Page  29 are pretty obvious without any explanation.

Clean Application Development – MVC architecture? ● This Page  30 would take a bit more digging to figure out.

Clean Application Development – Evolution ● Framework evolution ● Component Libaries ● Full (kitchen sink) Stack ● MVC ● Micro ● Action → Response ● Component-ized ● Middleware Page  31

Clean Application Development – Dependencies ● Composer and Packagist ● Prevents NIH ● Standardized autoloading ● Easier upgrades ● Promotes OSS ● Faster onboarding ● Public and Private code OR Page  32

Clean Application Development – Testing ● Unit testing = parachute ● Each test = one thing ● Ensures system functioning ● Makes refactoring easier ● The “Way of Testivus“ Page  33

Clean Application Development – TDD ● Important ● things should be done first Write failing tests first, then write the code required to make it pass. Page  34

Clean Application Development – QA and unit tests ● QA at the begining instead of the end ● QA waits for code to test. ● Create tests based on requirements, first. ● Developers write code to pass tests. ● Page  35 The end is not so bad now.

Clean Application Development – Agile ● Agile = Project Iteration ● Average sprint is 2 weeks ● At the end of the sprint EVERYTHING is “done“ ● Tests ● Development ● Documentation ● Velocity charts, MAKE THEM PUBLIC ● Charts allow business to recover gracefully Page  36

Clean Application Development – Human resources ● Our ● clients hired a professional, they should get one Professionals are: ● Trusted ● Reliable estimates ● Quality ● Replaceable ● Page  37 ● Promotable ● Documented ● Repeatable ● Vacation Use standards/conventions

Clean Application Development – Close ● Clean application development is: ● Learning, repetition, practice. ● Clear architecture. ● Coding standards and styles. ● Framework and best practices. ● Testing. ● Agile. ● Learning to say “NO“, and defend the code. ● Living up to the title “Professional“ Page  38

Clean Application Development – Resources ● Resources ● Adam Culp @adamculp ● http://www.GeekyBoy.com ● http://RunGeekRadio.com ● Book: “Clean Code“ by Robert C. Martin ● Book: “Refactoring“ by Martin Fowler ● https://github.com/adamculp/refactoring101 ● Book: “Refactoring 101“ by Adam Culp http://refactoring101.com ● Book: “Guide to PHP Design Patterns“ by Jason Sweat ● Book: “Design Patterns“ by Gang of four ● http://www.php-fig.org Page  40 Thank You!

Adam Culp
@adamculp

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We all face a daily battle to write good code for ourselves and others, deliver finished applications fast to satisfy business, and ensure everything is properly tested to prevent end-user fails. In this talk Adam Culp will discuss what “clean application development” is, and how it can help us win those battles. The talk will provide practical and usable examples to, integrate into your workflow, and continue to grow into good habits.