If you are not writing tests yet, you should start. Tests will improve the quality of your code, reduce bugs and probably force you to think more about design and quality. Actually, the hardest thing is to start and figure out which type of tests to write. So you start researching and you find a lot of different materials and get even more confused.Even when you decide what type of tests to use, it can be hard to decide how to test some specific logic in your app. Don’t give up! We have some tips we learned along the way that will hopefully make your life easier. In this talk you will hear about different test types and when to use them. We’ll also show some tools for checking quality of your test.

1. WHEN YOU GET LOST
IN API TESTING
Paula Čučuk & Antonio Perić - Mažar

2. About us
Paula Antonio
paula@locastic.com antonio@locastic.com
@paulala_14 @antonioperic
CEO @ LocasticBackend developer @ Locastic

3. Locastic
Helping clients create web
and mobile apps since 2011
• UX/UI
• Mobile apps
• Web apps
• Training & Consulting
www.locastic.com
@locastic

4. What happens when you
don’t write tests?

5. Destroyed 293 seconds
after liftoff because of
one wrong character in
formula
$135 million lost!

6. Not a rocket developer?

7. Writing tests benefits
Reducing the number of bugs
Improving code quality
Easier and faster refactoring
Time saving
Use-case based documentation

8. The test pyramid

10. Unit tests
Unit testing is a level of testing where individual
units/components are tested. The purpose is to
validate that each separate unit performs as expected.
A unit is the smallest testable part of any software.

12. It’s not unit tests, it’s you!
Refactor your code using SOLID principles.

13. Are unit tests enough?

15. Integration tests
Integration testing is the phase in software testing
in which individual software modules are combined and
tested as a group.

16. When to use integration tests
Validation
3rd party integration
Database queries
Verifying two or more modules which have unit tests work as expected
together

17. Functional tests
Functional testing is defined as the testing of
complete functionality of some application.

18. Functional tests
In each functional tests check:
Response code
Response header
Response content: contains expected fields in expected
format

19. Functional tests
Test that each endpoint behaves as expected for:
OK request and response
Bad request and Validation response
Forbidden access response

20. Let’s test puzzles!

21. Unit tests
Assert it has image
Assert it has puzzle shape
Assert it can be moved
Assert it can be merged

22. Integration tests
Assert two puzzles fit ok
together by shape and image

23. Integration tests
Assert it throws an exception
when combining two puzzles that
don’t fit together by shape

24. Integration tests
Assert it throws an exception
when combining two puzzles that
fit together by shape but don’t fit by
image

25. Functional tests
Assert it returns OK response
Assert it has correct headers

26. Functional tests
Assert it returns bad request response
Assert it has correct headers

27. What we learned along the way

28. Do I need to write tests first?
It’s just one of the approaches

29. Do I need to have 100% coverage?
100% coverage doesn’t guarantee your code is
fully tested and working

30. What about legacy code?
1. Start replicating bugs with tests before fixing them
2. Test at least most important and critical parts

31. How do I test some specific code?
Check out the tests of the libraries and framework you
are using

32. How do I know if the tests I wrote are good
enough?
Ask yourself:
“Am I sure the code I tested works as it should?”

33. Tools for checking test quality

34. Infection
Tool for mutation testing in PHP

35. PHP Stan
PHP Static Analysis Tool

36. Continuous integration (CI)
Tool for tuning tests on GIT

37. Handy testing tools

38. The test Http Client in API Platform
Created for PHPUnit
Manipulates the Symfony HttpKernel directly to simulate HTTP requests
and responses
Huge performance boost compared to triggering real network requests

39. The test Http Client in API Platform

40. PHP Matcher
Library that enables you to check your response against patterns.

41. PHP Matcher
Library that enables you to check your response against patterns.

42. Faker
Library for generating random data

43. Postman tests

44. Postman tests + Newman
Run and test a Postman Collection directly from the command line

45. Conclusion
• You should write tests!
• It’s important to write Unit, Integration and Functional tests
• If something is hard to test - refactor it
• Check out the tools we mentioned

46. Thank you!

47. Questions?
Paula Antonio
paula@locastic.com antonio@locastic.com
@paulala_14 @antonioperic
CEO @ LocasticBackend developer @ Locastic