Controlling complexity for large iOS projects

Presented at https://www.facebook.com/events/1779675885596534/
This talk discloses some points on bringing dependency hell back under control. It also includes demo of https://github.com/soxjke/WatchDogs

Transcript

1. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! Controlling complexity for large iOS projects Petro Korienev, iOS Engineer @ Techery
2. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! • Sporadic crashes • Intermittent issues • Hardly debuggable code PROBLEMS WHILE SCALING
3. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! • Result of deadlines pressure • Result of miscommunication • Result of laziness Growing number of dependencies and borrowed code
4. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! pod install…
5. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! • Complexity growth with time SO,
6. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! • Control decreases over time • Consequence of growing complexity • Maintainer change • Software is not an IP carrier, author is
7. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! FEW SLOC FACTS
8. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! CLOC ON MY CURRENT PROJECT
9. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! CLOC ON ITS PODS FOLDER
10. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! Few more numbers • Currently 11 iOS developers • 3 full-stack feature teams • 6 backend services + different environments • Analytics, perf monitoring, etc
11. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! Backend collaboration architecture
12. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! Backend collaboration architecture
13. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! Backend collaboration architecture
14. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! Monolithic vs Microservice
15. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! What to do
16. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! Here comes TRUST
17. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! • Trust in community and time-proven solutions • Trust in self TRUST
18. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! • AFNetworking 2.5.1-2.5.2 • OpenSSL heartbleed • Numerous zero-day exploits • Just bugs TRUST IN COMMUNITY
19. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! • “I’ve seen stuff like this before” • “This is pretty straightforward” • “If i’d do stuff like this, i’d do this way” TRUST IN SELF
20. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine !
21. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! • Bugs • Exploits • Limitations • Tech debt Consequences
22. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! Prefer control over trust CAPTAIN’S VOICE:
23. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! SOLUTIONS 1. Blackboxing 2. Whiteboxing 3. Grayboxing
24. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! BLACKBOXING - DON’T CARE OF IT • Simple • Unreliable • Tends to consume time when scaling
25. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! DON’T CARE OF IT
26. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! WHITEBOXING
27. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! WHITEBOXING • Very time-consuming • Reliable after certain effort put • Extremely difficult with closed- source
28. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! GRAYBOXING • Good tradeoff between white- and blackboxing • Flexible • Applicable almost everywhere • Dynamic
29. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! GRAYBOXING • Idea is to find a right place and inject something validating the correctness of contract • Unlike unit tests, verifies dynamic, run-time behaviour
30. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! EXAMPLE • https://github.com/soxjke/ WatchDogs
31. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! PROBLEM • Inconsistency and mess within CoreData across the project • Fake certainty in thread- access
32. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! SOLUTION AND DEMO
33. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! STEPS • Define problem places • Define ways to inject • Define ways to control
34. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! Define problem places • NSManagedObjectContext save • NSManagedObject getter/setter • Everything should run in context queue
35. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! Define ways to inject • swizzle save • swizzle setter/getter?
36. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! Define ways to inject • swizzle resolveInstanceMethod • use seamless swizzling
37. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! Define ways to control • swizzle NSManagedObjectContext init • dispatch_set_specific
38. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! THANK YOU FOR YOUR ATTENTION! Q&A TIME
39. ! #cocoaheadsukraine 29/Jun/2016 @ Sigma Software, Kharkiv, Ukraine ! YOU CAN FIND ME: • https://github.com/soxjke • http://stackoverflow.com/users/ 2392973/petro-korienev • https://www.facebook.com/soxjke • https://twitter.com/soxjke