![List[Int]
=>
isPalindrome(list)
(list.reverse
==
list)
==>
isPalindrome(list)
(list.reverse
!=
list)
==>
!isPalindrome(list)
Limits](https://image.slidesharecdn.com/thehitchhickersguidetounittesting-130526112442-phpapp02/85/The-hitchhicker-s-guide-to-unit-testing-50-320.jpg)
The hitchhicker’s guide to unit testing
- 1. The hitchhicker’s guide to unit tes1ng Rémy-‐Christophe Schermesser @el_picador
- 2. Ruby! Scala! Java! Python! PHP!
- 3. Ruby! Scala! Java! Python! PHP! But don’t forget your towel
- 4. Test::Unit ScalaTest jUnit uniFest PHPUnit
- 5. Test::Unit ScalaTest jUnit uniFest PHPUnit Again don’t forget your towel
- 6. JUnit
- 7. assertEquals At the beginning, we had
- 9. And void testWithCamelCase ToReadItBeFer() { ... }
- 10. And again @Test void annotaZonsAreGood ForYourHealth() { ... }
- 11. And again again void testMyTest() { Obj obj = new Obj(); // 10 lignes of things assertEquals(…); }
- 12. JUnit
- 13. JUnit Mocks
- 15. JUnit Behavior tes1ng with RSpec
- 16. Problem void testMyTest() { Obj obj = new Obj(); // 10 lignes of things assertEquals(…); }
- 17. Behavior tesZng, don’t test, do describe Describe what your program should do
- 18. One test One (english) sentence Behavior tesZng, don’t test, do describe
- 19. RSpec, don’t panic, factorize and do DSL
- 20. describe CompaniesController do describe "POST create" do context "when recruiter signed_in with no company" do … end end end
- 21. describe CompaniesController do describe "POST create" do context "when recruiter signed_in with no company" do … end end end
- 22. describe CompaniesController do describe "POST create" do context "when recruiter signed_in with no company an email is sent" do … end end end
- 23. let!(:recruiter) { login_recruiter create(:recruiter, company_id: nil) } context "when good params" do let(:params) { … } it { expect { post :create, params }.to change(Company, :count).by 1 } it { expect { post :create, params }.to change(Ac1onMailer::Base.deliveries, :count).by 2 } end “When recruiter signed_in with no company”
- 24. let!(:recruiter) { login_recruiter create(:recruiter, company_id: nil) } context "when good params" do let(:params) { … } it { expect { post :create, params }.to change(Company, :count).by 1 } it { expect { post :create, params }.to change(Ac1onMailer::Base.deliveries, :count).by 2 } end “When recruiter signed_in with no company”
- 25. let!(:recruiter) { login_recruiter create(:recruiter, company_id: nil) } context "when good params" do let(:params) { … } it { expect { post :create, params }.to change(Company, :count).by 1 } it { expect { post :create, params }.to change(Ac1onMailer::Base.deliveries, :count).by 2 } end “When recruiter signed_in with no company”
- 26. let!(:recruiter) { login_recruiter create(:recruiter, company_id: nil) } context "when good params" do let(:params) { … } it { expect { post :create, params }.to change(Company, :count).by 1 } it { expect { post :create, params }.to change(Ac1onMailer::Base.deliveries, :count).by 2 } end “When recruiter signed_in with no company”
- 27. Like a towel, use it every day
- 28. JUnit Muta1on tes1ng Behavior tes1ng with Javalanche
- 29. Code coverage has limits Code: ctrl+c Test: ctrl+v
- 30. Code a class and test it
- 31. Mutate it
- 32. && ++ != > … || -‐-‐ == < … Mutate it
- 33. if(a && b) { i++; } else { i-‐-‐; } if(a || b) { i++; } else { i--; } if(a && b) { i--; } else { i--; } Mutate it
- 34. Kill it
- 35. mvn test ant -‐f javalanche.xml mutaZonTest Kill it
- 36. Run tests Green tests Something’s wrong
- 37. Run tests Red tests Great job!
- 38. Coverage data Equivalent mutant if(index >= 10) break and if(index == 10) break Selec1ve muta1on Parallel execu1on Choose your mutants wisely Using code coverage to reduce the tests to run Speed-‐up The right tool
- 41. Behavior tes1ng JUnit Property tes1ng Muta1on tes1ng with ScalaCheck
- 42. How to test string concatenaZon ? assert( ("ta" + "a") == "taa" )
- 43. How to test string concatenaZon ? assert( ("ta" + "a") == "taa" ) assert( ("ta" + "b") == "tab" )
- 44. How to test string concatenaZon ? assert( ("ta" + "a") == "taa" ) assert( ("ta" + "b") == "tab" ) …
- 45. How to test string concatenaZon ? assert( ("ta" + "a") == "taa" ) assert( ("ta" + "b") == "tab" ) assert( ("ta" + "z") == "taz" ) …
- 46. How to test string concatenaZon ? assert( ("ta" + "a") == "taa" ) assert( ("ta" + "b") == "tab" ) assert( ("ta" + "z") == "taz" ) … But boring
- 47. ∀n∈N, ∃!k∈N (n = 2k ⋁ n = 2k+1) Remember math class? ∀n, n = 42
- 48. val n: Int val k: Int (n == 2k || n == 2k + 1) == true (n % 2 == 0 || n % 2 == 1) == true In code
- 49. val a: String val b: String ((a+b) endsWith b) == true ((a+b) startsWith a) == true (a+b).length == a.length + b.length String concatenaZon properZes
- 50. List[Int] => isPalindrome(list) (list.reverse == list) ==> isPalindrome(list) (list.reverse != list) ==> !isPalindrome(list) Limits
- 52. Behavior tesZng Every day MutaZon tesZng CriZcal code Property tesZng à CriZcal code Share and Enjoy
- 53. So Long, and Thanks for All the Fish Rémy-‐Christophe Schermesser @el_picador
- 54. Rémy-‐Christophe Schermesser @el_picador Behavior tesZng Rspec (ruby) Jasmine (javascript) MutaZon tesZng Javalanche (java) Mutant (ruby) Property tesZng ScalaCheck (scala) QuickCheck (haskell) MrProper (ruby)