Introducing Tests to Legacy Applications

SDPHP
June 2025
https://www.meetup.com/sandiegophp/events/308418312

Transcript

1. Introducing Tests to Legacy Applications Marcus Moore June 2025
2. what is automated testing? • (briefly)
3. why? • I don't trust myself • No one can remember everything • Improved confidence moving forward
4. when? • Yesterday • Today • Before refactoring • When writing new code • or before it is merged • Before starting a bug fix
5. how? • Start small. Know that it will take time • Get buy-in from the team • (I) skip browser testing and stick with phpunit/pest • CI
6. foundation • Each test starts "clean" and builds up the world it needs • Application state needs to be cleared after each test • Laravel handles database via migrations and RefreshDatabase trait • DBML to Migration Files
7. foundation - organization It's ok to have a bunch of test classes • UserTest • CreateUserTest • ShowUserTest • UpdateUserTest
8. foundation - naming testSomething(){ } test_something(){ } !"Test] something(){ }
9. foundation - naming testRevertsPendingChangesAfterTenDaysIfNotApprovedByAdministrator(){ } test_reverts_pending_changes_after_ten_days_if_not_approved_by_administrator(){ }
10. foundation - test class structure • setUp() • permissions • validation • cannots • cans • helpers
11. the process - test method structure !" Arrange Settings!#enableMaintenanceMode(); !" Act $response = $this!$get('/home'); !" Assert $response!$assertSee('Come back later!');
12. the process - in practice • Replicate the bug • Write a failing test to demonstrate the failure • Fix the bug
13. the process - in practice • Unit test helper functions as you come across them • maybe PR it separately? • Fight the urge to refactor • Sometimes it's best just to document the current behavior even if it is a "bug"
14. diving in • snipe-it - A free open source IT asset/license management system
15. code coverage • don't shoot for 100% coverage • coverage report
16. • Edit Your Profile • ProfileController
17. • Test branching! (if/else/switch/match/etc) • Goal: Reduce duplication
18. !
19. (you should volunteer to present)
20. Chris Hartjes (The Grumpy Programmer's Guide To Testing PHP Applications)
21. Noah Sussman (The Grumpy Programmer's Guide To Testing PHP Applications)
22. Resources • Chris Hartjes (grumpy programmer) • Book - The Grumpy Programmer’s Guide To Testing PHP Applications • Book - The Complementary PHP Testing Tools Cookbook • Video - You're (Probably) Testing Things Wrong
23. Resources • php[architect] Magazine • php[tek]
24. Resources • Legacy to Laravel: How to Modernize an Aging PHP Application
25. ❓