Why We Test

In this talk, Stuart looks back over his career at the common excuses he's heard about why people do not or cannot test, and then takes a look at the wider world for examples of how testing can make a positive difference to companies and organisations.

Exclusively performed live @PHPOxford in 28th October, 2015.

Transcript

1. A presentation by @stuherbert
 for @GanbaroDigital A Look At Why Testing Makes A Difference Why Do We Test?
2. @GanbaroDigital Do you test at all?
3. @GanbaroDigital Why don’t you test?
4. @GanbaroDigital Here are some excuses
5. @GanbaroDigital Testing Is Expensive • Comprehensive testing can add 40% to the time it takes to create an app
6. @GanbaroDigital Testing Isn’t Paid For • “My customer is paying for shipped features, not for tests.”
7. @GanbaroDigital Testing Isn’t Needed • “My code is good enough, even without tests.”
8. @GanbaroDigital Testing Is Hard • “It’s really hard to write unit tests for my code.”
9. @GanbaroDigital Testing Isn’t Allowed • “My manager won’t let me write tests.”
10. @GanbaroDigital The Excuses • Testing is expensive • Testing isn’t paid for • Testing isn’t needed • Testing is hard • Testing isn’t allowed
11. @GanbaroDigital We’ll revisit these excuses.
12. @GanbaroDigital Why do you test?
13. @GanbaroDigital Why do they test?
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17. @GanbaroDigital • Keep users safe • Meet industry regulations • Meet legal requirements
18. @GanbaroDigital Testing is often used to prove that bad things won’t happen.
19. @GanbaroDigital There are other, positive reasons to test.
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23. @GanbaroDigital • Competitive advantage • Reduce after-sales costs • Get paid
24. @GanbaroDigital Busting The Excuses • Testing is expensive • Testing isn’t paid for • Testing isn’t needed • Testing is hard • Testing isn’t allowed
25. @GanbaroDigital If you don’t have the time to do it right first time, when will you have the time to put it right?
26. @GanbaroDigital Busting The Excuses • Testing is expensive • Testing isn’t paid for • Testing isn’t needed • Testing is hard • Testing isn’t allowed
27. @GanbaroDigital You’re being paid to deliver something that works. Tests provide the evidence that it’s ready to deliver.
28. @GanbaroDigital Busting The Excuses • Testing is expensive • Testing isn’t paid for • Testing isn’t needed • Testing is hard • Testing isn’t allowed
29. @GanbaroDigital Functional requirements are the things your app must do. Non-functional requirements are the constraints on your solution.
30. @GanbaroDigital Busting The Excuses • Testing is expensive • Testing isn’t paid for • Testing isn’t needed • Testing is hard • Testing isn’t allowed
31. @GanbaroDigital Testable code is reusable.
32. @GanbaroDigital Busting The Excuses • Testing is expensive • Testing isn’t paid for • Testing isn’t needed • Testing is hard • Testing isn’t allowed
33. @GanbaroDigital Quit. Work somewhere else.
34. @GanbaroDigital Busted Excuses?
35. @GanbaroDigital These are all good points. But the main reason that we need to test can be found in the history books.
36. @GanbaroDigital Those who do not study history are doomed to repeat it. - programming proverb
37. @GanbaroDigital What happened to the professions that came before ours?
38. @GanbaroDigital All the “old” professions became regulated professions.
39. @GanbaroDigital Regulation of Professions • Regulated practices • Professional standards body • Licensed professionals
40. @GanbaroDigital Think it can’t happen to us? Think again.
41. Stuart Herbert ~ @stuherbert Founder @GanbaroDigital