Why You Can't Test

Slides for a talk I gave at CakeFest 2014 about obstacles developers face when they decide to start writing automated tests for their code.

Transcript

1. WHY YOU CAN'T TEST Chris Hartjes - CakeFest 2014 August 24, 2014
3. Testing Is Hard
5. 7 Obstacles
6. Configuration Configuring tools is difficult
7. Configuration Use Composer (http://getcomposer.org) to isolate tools to your project Modify your project to fit the defaults of tools whenever possible Avoid fighting with tools but also resist urge to write your own
8. Configuration Composer + Packagist = library management Keeps dependencies as part of the project
9. Configuration { "require": { "fabpot/goutte": "1.0.*@dev", "igorw/yolo": "~42.0@dev" } }
10. Configuration Making your own packages available is easy Standard locations for files reduces confusion
11. Configuration Avoid “my project is SOOOOO unique” mentality Makes it increasingly difficult to integrate other projects Convention over configuration matters
12. Education Developers not taught how to test
13. Education
14. Education Impossible to learn how to write tests in isolation Mentorships are awesome! (http://phpmentoring.org) Talking about mentoring is awesome (#phpmentoring on Freenode)
15. Education It takes two to test
16. Education
17. Education Mentoring is a great way to make connections My own apprentices have gone on to success Easy way to give back to the community
18. Education
19. Coupling Tightly-coupled code common
20. Coupling Learn about dependency injection Learn about Demeter’s Law Understand WHY coupling is bad
21. Coupling You probably know DI by a less-complicated name You probably already do it
22. Coupling
23. Coupling DI Containers / Service Locators Constructor injection Setter injection
24. Coupling Containers are simply a way to store something for later retrieval Think “define stuff in my bootstrap sequence”
25. Coupling
26. Coupling
27. Coupling Dependency Injection Containers and Service Locators are simply globally-available ways to retrieve stuff Be sure to not make you code dependant on the container / locator!
28. Dependencies Too many dependencies
29. Dependencies You never know it until you try to create mocks for them Every dependency you add needs to be justified
30. Dependencies “Mocking” is the creation of copies of dependencies the code you are testing has You create those copies in a specific state Easiest way to see if your code is testable — can you easily inject dependencies in?
31. Dependencies http://www.littlehart.net/atthekeyboard/2012/03/27/ metatesting-understanding-mock-objects/
32. Misconceptions “You are paid to write code, not tests!”
33. Misconceptions Getting paid not to write code, but to solve problems Many people discount the costs of fixing bugs Many people discount the costs of missed opportunities bugs create
34. Misconceptions TDD is about shifting bug-fixing to a cheaper part of the process TDD is a design pattern! 20% to 40% more time for 40% to 90% fewer bugs
35. Misconceptions Tests can help you go home from work on time every day
36. Misconceptions Bugs found in development cost $X Bugs found by QA cost $2X Bugs found in production cost $10X
37. Environments Lack of control over environments
38. Environments Composer can play double duty Vagrant / other virtual machines are key Repeatable automated processes are key
39. Environments Composer lets you lock down the environment Easy to specify versions of all libraries Reduce likelihood of “works on my machine”
40. Environments http://vagrantup.com Learn it, live it, love it
41. Environments People make mistakes all the tie Computers make mistakes you tell them to Examine procedures carefully to find automation opportunities
42. Motivation Maintenance programming sucks
43. Motivation Good test suites make bug fixes easy Good test suites make it easier to integrate new things
44. Motivation Good test suites mean more time worrying about big problems Good test suites mean less time worrying about regressions
45. Shameless Self-Promotion http://grumpy-testing.com http://grumpy-phpunit.com
46. Feed My Ego chartjes@littlehart.net @grmpyprogrammer ASK ME ANYTHING - I READ ALL EMAIL AND TWEETS https://joind.in/11602