Test Smarter, Not Harder

Testing your application is hard. Writing tests seems like a never ending story of database fixture changes. Some parts of your system seem like they can't be tested. When using a framework, it may feel like you're stuck with functional/feature testing only. Your test suite grows and becomes slower over time. At some point, it may feel like it's no longer serving its purpose.

Learn how to build your own testing strategy. Learn how to apply the right amount of testing at the appropriate level, to make your tests run faster.

Talk inspired by "Lightning Fast Tests" talk by Jakub Zalas.

Transcript

1. Test smarter, not harder Glasgow PHP meetup – 19 November 2024
2. Marek Matulka Freelance software engineer @super_marek Photo by @cakper
3. Why testing is di cult?
4. Different types of tests Manual testing End-2-end testing UI testing Integration testing Acceptance testing Service testing Unit testing
5. Functional/feature/integration testing Manual testing End-2-end testing UI testing Integration testing Acceptance testing Service testing Unit testing Controller Repository Service A Api Service B Service C
6. Unit testing Manual testing End-2-end testing UI testing Integration testing Acceptance testing Service testing Unit testing Controller Service A Service B Service C
7. (Lack of) speed is not only the issue Fast Reliable Good feedback Grow linearly Force better design Isolated Slow Fragile Poor feedback Grow exponentially Put pressure off design Can simulate user journeys Unit tests Feature/Functional tests
8. Test pyramid Unit Service UI
9. Inverted test pyramid Feature / Functional Integration Service Unit
10. Testing ice-cream cone Feature / Functional Integration Service Unit Manual tests
11. Unit testing
12. Let's implement ticket price calculator • a simple service that calculates taxes for given route • tickets with fare information are stored in the local database • taxes are provided by a third party API for route and fare
13. A quick solution TicketPriceCalculator EntityManager HttpClient
14. A quick solution TicketPriceCalculator EntityManager HttpClient
15. Test doubles
16. Unit testing the calculator TicketPriceCalculator EntityManager HttpClient Don't mock what you don't own!
17. So… I cannot mock it? But I need more Unit test?!
18. TicketPriceCalculator EntityManager HttpClient DB HTTP Integration tests Unit tests
19. Unit testing the calculator TicketPriceCalculator TicketRepository HttpClient
20. Unit testing the calculator TicketPriceCalculator TicketRepository TaxCalculator
21. Unit testing the calculator TicketPriceCalculator TicketRepository TaxCalculator
22. Unit testing the calculator TicketPriceCalculator TicketRepository TaxCalculator
23. Unit testing the calculator TicketPriceCalculator TicketRepository TaxCalculator
24. Unit testing the calculator TicketPriceCalculator TicketRepository TaxCalculator
25. TicketPriceCalculator EntityManager HttpClient DB HTTP Integration tests Unit tests
26. TicketPriceCalculator EntityManager HttpClient DB HTTP Integration tests Unit tests
27. TicketPriceCalculator EntityManager HttpClient DB HTTP Integration tests Unit tests TicketRepository TaxCalculator
28. TicketPriceCalculator EntityManager HttpClient DB HTTP Integration tests Unit tests TicketRepository TaxCalculator DoctrineTicketRepository HttpTaxCalculatorClient
29. Integration test for the repository TicketPriceCalculator TicketRepository TaxCalculator DoctrineTicketRepository
30. Two sides of the contract TicketPriceCalculator TicketRepository TaxCalculator DoctrineTicketRepository • An interface is a contract • User of the interface makes an assumption about the behaviour with test doubles • Implementation of the interface needs to prove it implements the contract fully • For each expectation in the unit test there should be at least one test to verify that expectation
31. TicketPriceCalculator EntityManager HttpClient DB HTTP Integration tests Unit tests TicketRepository TaxCalculator DoctrineTicketRepository HttpTaxCalculatorClient
32. Unit testing the tax calculator TicketPriceCalculator TicketRepository TaxCalculator DoctrineTicketRepository ExternalApiTaxCalculator ExternalApi ExternalApiHttpClient
33. Unit testing the tax calculator TicketPriceCalculator TicketRepository TaxCalculator DoctrineTicketRepository ExternalApiTaxCalculator ExternalApi ExternalApiHttpClient
34. Integration test for the API TicketPriceCalculator TicketRepository TaxCalculator DoctrineTicketRepository ExternalApiTaxCalculator ExternalApi ExternalApiHttpClient
35. Integration test for the API TicketPriceCalculator TicketRepository TaxCalculator DoctrineTicketRepository ExternalApiTaxCalculator ExternalApi ExternalApiHttpClient
36. TicketPriceCalculator EntityManager HttpClient DB HTTP Integration tests Unit tests TicketRepository TaxCalculator DoctrineTicketRepository HttpTaxCalculatorClient
37. TicketPriceCalculator EntityManager HttpClient DB HTTP Integration tests Unit tests TicketRepository TaxCalculator DoctrineTicketRepository HttpClientExternalApi
38. TicketPriceCalculator EntityManager HttpClient DB HTTP Integration tests Unit tests TicketRepository TaxCalculator DoctrineTicketRepository HttpClientExternalApi ExternalApi
39. TicketPriceCalculator EntityManager HttpClient DB HTTP Integration tests Unit tests TicketRepository TaxCalculator DoctrineTicketRepository HttpClientExternalApi ExternalApiTaxCalculator ExternalApi
40. Hexagonal Architecture Ports & Adapters
41. TicketPriceCalculator TaxCalculator TicketRepository ExternalApi ExternalApiTaxCalculator
42. TicketPriceCalculator TaxCalculator TicketRepository ExternalApi ExternalApiTaxCalculator DoctrineTicketRepository EntityManager
43. TicketPriceCalculator TaxCalculator TicketRepository ExternalApi ExternalApiTaxCalculator DoctrineTicketRepository HttpClientExternalApi EntityManager HttpClient
44. TicketPriceCalculator TaxCalculator TicketRepository ExternalApi ExternalApiTaxCalculator DoctrineTicketRepository HttpClientExternalApi EntityManager HttpClient InMemoryTicketRepository
45. TicketPriceCalculator TaxCalculator TicketRepository ExternalApi ExternalApiTaxCalculator DoctrineTicketRepository HttpClientExternalApi EntityManager HttpClient InMemoryTicketRepository UI
46. TicketPriceCalculator TaxCalculator TicketRepository ExternalApi ExternalApiTaxCalculator DoctrineTicketRepository HttpClientExternalApi EntityManager HttpClient InMemoryTicketRepository UI TicketPriceController Symfony/Laravel
47. TicketPriceCalculator TaxCalculator TicketRepository ExternalApi ExternalApiTaxCalculator DoctrineTicketRepository HttpClientExternalApi EntityManager HttpClient InMemoryTicketRepository UI TicketPriceController Symfony/Laravel BehatContext Behat
48. TicketPriceCalculator TaxCalculator TicketRepository ExternalApi ExternalApiTaxCalculator DoctrineTicketRepository HttpClientExternalApi EntityManager HttpClient InMemoryTicketRepository UI TicketPriceController Symfony/Laravel BehatContext Behat FakeExternalApi
49. How to use fakes in Feature/Functional tests?
50. Using Fake
51. How to use a fake service in Laravel?
52. How to use a fake service in Symfony?
53. How to use a fake service in Laravel?
54. EMPOWER YOUR TESTING
55. Use Behat with examples in Gherkin
56. Write a failing scenario (feature)
57. Write a failing scenario (feature) Write a failing test
58. Write a failing scenario (feature) Write a failing test Make your test pass
59. Write a failing scenario (feature) Write a failing test Make your test pass Refactor your code
60. Write a failing scenario (feature) Write a failing test Make your test pass Refactor your code Repeat the fail-pass-refactor cycle as necessary
61. Write a failing scenario (feature) Write a failing test Make your test pass Refactor your code Make your feature pass
62. Write a failing scenario (feature) Write a failing test Make your test pass Refactor your code Make your feature pass BDD TDD
63. Write a failing scenario (feature) Write a failing test Make your test pass Refactor your code Make your feature pass BDD TDD External Quality Internal Quality
64. Flexible Behat Unit tests Modelling by Example Acceptance tests Use Fakes instead of DB/APIs. Smoke tests Verify critical user paths
65. Thank you 🤗