Clean Tests

Clean test presentation,
Kiev JUG, 23.2.17

Transcript

1. Clean Tests Noam Almog | Tech Lead linkedin github.com/noam-almog @NoamSon noama@wix.com
2. Hi. Tech Lead Wix.com Noam Almog
3. AGENDA Intro Review Test Structures Refactor each part of the test Conclude
4. Should I Clean ? § Test lasts More than production Code. § More Lines of code § Read and reviewed More
5. If you let the tests rot, then your code will rot too “ “ Robert C. Martin
6. What Is ”Good” ? § How easy is it to extend it ? § When break, is it easy to fix ? § How many “Rewrite” calls ?
7. Test Structure 01
8. Test Structure § Test is a Map to your code. § Reveille the right amount of details. § Should be Consistent (*)
9. Test Structure
10. From Testing Code to Testing Behavior
11. Structure Pitfalls Test only one thing
12. Structure Pitfalls Hide Too Much Data
13. Send Mail invoke
14. New Test 01
15. Test Description § Use Plain English § Use Simple Language – Not Code ! § Find a sentence structure § “throw an exception if user does not exist” § “send an email to the the email registered with the site-id”
16. Test Description Does not Compile
17. Test Setup 02
18. Can A Single Test Case Stand on His own
19. Extract Setup to Methods § Select method name that implies structure § Starts with given § Contain the collaborator name § Describe the defined Behavior § Reverse the order of parameters § Use parameter names to show what is important
20. Describe the What are testing, NOT How you are testing
21. Simplify The Code § Do not use concrete values in the test. § Reduce number of moving parts § Do not move important logic out of the scope
22. Extract Drivers § Move all setup method to it § Move all related variables to it § Split according to the Subject
23. When is a good time to start ? Now !
24. Test Action 03
25. Test Action § Should be a single statement § Do NOT hide !
26. Test Expectations 04
27. Matchers, Why ? § Readable § Better Failure Messages § Reusable and Flexible
28. Matcher libraries § Hamcrest (Java) § Chai (JS) § Specs2/ScalaTest (Scala)
29. Match Expectations § Use just one matcher § Describe what you are matching, now how § Don’t define any new variables
30. Use Only what You Defined
31. Failure Messages Can you tell me why this failed ?
32. Conclusion § Test behavior and not code § Test Should stand on his own § Describe what and not how § Start today, don’t wait for tomorrow § Use only variables you defined
33. Thank You linkedin github.com/noam-almog @NoamSon noama@wix.com
34. Q&A linkedin github.com/noam-almog @NoamSon noama@wix.com