Clean Application Development

No matter what level of development we are at in our careers 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 tested to prevent end-user fails. In this talk we 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 take with you, integrate into your workflow, and continue to grow into good habits.

Transcript

1. Adam Culp @adamculp https://joind.in/10797 Clean Application Development
2. Page  2 • About Me • PHP 5.3 Certified • Consultant at Zend Technologies • Organizer – SoFloPHP (South Florida) • Organized – SunshinePHP (Miami) • Long distance (ultra) runner • Judo Black Belt Instructor Clean Application Development – About Me
3. Page  3 • I love iteration! • Evolution. • Learning to walk. • Training to run. • Evading project managers. • Clean development. Clean Application Development – Iteration
4. Page  4 • 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“. Clean Application Development – Learning
5. Page  5 • A great resource on code quality. Clean Application Development – Resources Clean Code By Robert C. Martin
6. Page  6 • Disasters happen, resulting in bad code... • It's easy • Short deadlines • Boss • Laziness • Lack of “how-to“ • Come back and clean later • We are the cause! Clean Application Development – Causes of bad code
7. Page  7 • Bad code starts innocently • Hire a new professional/developer • Clean slate, no expectations • Start a new project • Initial code output is quick and easy, setting expectation • Slows down over time • Complexity increases • Domino effect Clean Application Development – Typical Scenario
8. Page  8 • Our responsibility to say “NO“ • Managers job = defend schedule and features • Our job = defend the code • Managers respect realistic reasons and explanations Clean Application Development – Defend the code
9. Page  9 • 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“ Clean Application Development – We are judged And they talk about it!
10. Page  10 • Side-effects of bad code: • Wasted Time • Bugs • Excessive debugging • Procrastination • Missed deadlines • Technical debt • Financial losses Clean Application Development – Result of bad code
11. Page  11 • How we typically react to a dirty application: • Padded estimates • Developers Hide • Become defensive • Blame others/requirements • Add developers • Rewrite! Clean Application Development – The aftermath
12. Page  12 • 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! Clean Application Development – Rewrite problems
13. Page  13 • Learn to Refactor. Clean Application Development – Resources Refactoring 101 By Adam Culp Refactoring By Martin Fowler https://github.com/adamculp/refactoring101 https://refactoring101.com
14. Page  14 • 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. Clean Application Development – Common sense
15. Page  15 • Coding Standards save time • Gives direction • PHP Framework Interoperability Group (https://www.php-fig.org). • PSR-0 Autoloading Standard • PSR-1 Basic Coding Standard • PSR-2 Coding Style Guide • PSR-3 Logging • PSR-4 Improved Autoloading • Standard NOT important • Choose one • Stick with it • Consistency is key Clean Application Development – Coding standards
16. Page  16 • Names should be clear • Functions and variables should tell a story. Clean Application Development – Clear names $elapsedTimeInDays; $daysSinceCreation; $daysSinceModified; $fileAgeInDays; $elapsed; $createdDays; $modifiedDays; $age; Good Bad
17. Page  17 • Shy away from variations of the same name • To ensure names are different enough to portray difference. Clean Application Development – No confusion $product $productInfo $productData $productDescription What is the difference between these?
18. Page  18 • Certain characters are hard to understand Clean Application Development – Bad characters Lower case L Uppercase O (oh) Uppercase I (eye) Bad
19. Page  19 • Technical names help developers who actually read the code. • Non-technical terms for client documentation. • Class 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. • Ex. - fetch, get, add, update, remove, delete Clean Application Development – Name grammar
20. Page  20 • 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 Clean Application Development – Clean code
21. Page  21 • Comments can also be a bad “smell“ • Comments are often used to cover up bad code. • Code should be self-documenting Clean Application Development – Code comments
22. Page  22 • 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 Clean Application Development – Smells of bad code
23. Page  23 • Let PHP CodeSniffer detect bad smells • Set rules to detect if coding standard is not followed • Run during commits in version control • PhpStorm integration Clean Application Development – Code sniffer
24. Page  24 • Peer code review great learning tool • Peers help train each other on strong points. • Fresh set of eyes. • Builds better teams. Clean Application Development – Peer code reviews
25. Page  25 • 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 Clean Application Development – Design Patterns
26. Page  26 • Frameworks help keep things in line • $evil = 'roll-your-own' • Knowledge transfer • Onboarding • Insecure • Allows code to be lighter, simpler • Does heavy lifting • Most modern frameworks are MVC • Model – Business logic, Data • View – GUI, Presentation • Controller – Directs, Commands • STICK TO IT!!! Clean Application Development – Frameworks
27. Page  27 • We can tell pretty simply this “looks“ like a library. (bookshelves, computers, book categories) Clean Application Development – Clear architecture
28. Page  28 • These are pretty obvious without any explanation. Clean Application Development – Obvious purpose
29. Page  29 • This would take a bit more digging to figure out. Clean Application Development – MVC architecture?
30. Page  30 • Unit testing = parachute • Each test = one thing • Ensures system functioning • Makes refactoring easier • The “Way of Testivus“ Clean Application Development – Testing
31. Page  31 • Important things should be done first • Write failing tests first, then write the code required to make it pass. Clean Application Development – TDD
32. Page  32 • 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. • The end is not so bad now. Clean Application Development – QA and unit tests
33. Page  33 • 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 • Burn down chart allow business to recover gracefully Clean Application Development – Agile
34. Page  34 • Our clients hired a professional, they should get one • Professionals are: • Trusted • Reliable estimates • Quality • Replaceable • Promotable • Documented • Repeatable • Vacation • Use standards/conventions Clean Application Development – Human resources
35. Page  35 • 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“ Clean Application Development – Close
36. Page  36 • Coming soon! • End of year on LeanPub Clean Application Development – The Book Clean Application Development By Adam Culp https://cleanappdev.com
37. Page  37 • Resources • Adam Culp @adamculp • https://joind.in/10797 • 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: “Clean Application Development“ by Adam Culp http://cleanappdev.com • Book: “Guide to PHP Design Patterns“ by Jason Sweat • Book: “Design Patterns“ by Gang of four • http://www.php-fig.org Clean Application Development – Resources Thank You!