NSSpain 2023: Moving from Cocoapods to SwiftPM

Discover the realities and challenges of adopting Swift Package Manager in the XING iOS app, to be able to organize and design the modularization of more than 100 internal libraries.

Transcript

1. Moving from Cocoapods to Swift Package Manager Oswaldo Rubio & Juantri Jimenez Our journey
2. Who we are? iOS Platform team members at XING Oswaldo Rubio Juantri Jimenez
3. What is XING?
4. The problems and solutions we found while adopting gradually Swift Package Manager in a large codebase What’s the point?
5. A bit of context 🎒 👨💻 👩💻 + 30 iOS Developers +120 Development Pods ~30% ⏳ + 13 years old codebase (monorepo) 📈 + 300K daily unique visitors 📚 + 300K LOC 📐 50% UIKit + 50% SwiftUI
6. The reasons behind 1. Reduce our technical debt 2. Having a more f lexible and capable Package manager 3. Having better build times & developer experience moving to SPM
7. The problem 🤯
8. The problem 🤯 1. More than 20 dependencies per module (average) 2. High transitive dependency usage 3. 30% of mixed Objective-C code across the project
9. 🧪 The experiment … and what we learned during a Hackweek 1. Dependencies from our features modules needs to be removed 2. Inter-dependency between modules needs to be reduced 3. A roadmap needs to be de f ined 4. Our managers and community needs to be convinced
10. Our journey starts here
11. 📦 Dependencies
12. Third party dependencies
13. Third party dependencies App Dependency1 Dependency2 Dependency3 Feature1 Feature2 Common1 Common2 🟦 Pod.xcodeProj
14. Third party dependencies App Dependency1 Dependency2 Dependency3 Feature1 Feature2 Common1 Common2 🟦 Pod.xcodeProj
15. Third party dependencies App Dependency1 Dependency2 Dependency3 Feature1 Feature2 Common1 Common2 📦 dependencies Package 🟦 Pod.xcodeProj
16. Conditional Dependencies
17. 📉 Complexity reduction
18. Thomas J. McCabe, Sr in 1976 - Wikipedia "It´s a quantitative measure of the number of linearly independent paths through a program’s source code.”
19. Predicting Subsystem failures using dependency graphs, 2016 - Microsoft “The complexity of the dependency structure predicts the number of defects.”
20. Tooling - jungle https://github.com/xing/jungle Complexity = E - V + P E - Edges V - Nodes P - Weakly connected components Complexity: 4 - 5 + 1 = 0 Complexity: 6 - 5 + 1 = 2
21. You can’t improve what you don’t measure.
22. Reducing complexity in our project Last 3 years
23. Less complexity, less build time Complexity: 55 Complexity: 3
24. 🛣 We need a roadmap
25. 🛣 We need a roadmap • De f ine a migration plan • Document our migration process • Get a time estimation of the overall process • Get our managers and community approval
26. Migration plan tooling
27. We have a roadmap
28. 🛠 The Migration
29. 🛠 The Migration Gradual and using both package managers Non invasive for other teams Integrate as fast as possible
30. • Module migration status • Product containers • SPM Schemes management • One or Multiple Swift Packages • Using SPM products in Cocoapods • Cyclic dependencies between languages Migration challenges
31. • Module migration status • Product containers • SPM Schemes management • One or Multiple Swift Packages • Using SPM products in Cocoapods • Cyclic dependencies between languages Migration challenges
32. Module migration status Migrated Integrated Module Availability Cocoapods and SPM Only SPM Module usage for running With CocoaPods With SPM Module usage for Testing With SPM With SPM
33. Original status 📲 XING App 🟦 Pod.xcodeProj JobsCoreTests JobsCore 📂 JobsCore/Sources 📂 JobsCore/Tests
34. Migrated status 📦 features Package 📲 XING App 🟦 Pod.xcodeProj JobsCoreTests JobsCore 📂 JobsCore/Sources JobsCoreModule 📂 JobsCore/Tests
35. Integrated status 📦 features Package 📲 XING App JobsCoreTests JobsCore 📂 JobsCore/Sources 📂 JobsCore/Tests
37. • Module migration status • Product containers • SPM Schemes management • One or Multiple Swift Packages • Using SPM products in Cocoapods • Cyclic dependencies between languages Migration challenges
38. Product container
39. • Module migration status • Product containers • SPM Schemes management • One or Multiple Swift Packages • Using SPM products in Cocoapods • Cyclic dependencies between languages Migration challenges
40. SPM schemes management
41. • Module migration status • Product containers • SPM Schemes management • One or Multiple Swift Packages • Using SPM products in Cocoapods • Cyclic dependencies between languages Migration challenges
42. One package or multiple ones?
43. New Swift 5.9 Package Access modi f ier Private Open Public Internal Fileprivate Package 🆕
44. One package or multiple ones? Cocoapods App Pod1 Pod2 Pod3 Pod4 Pod5 Pod6 SPM App Prod1 Package1 Package2 Prod2 Prod10 Prod11 Target1 Target2 Target10 Target11 Target3 Pod f ile All dependencies allowed Only Products are accessible to other packages
45. One package or multiple ones?
46. • Module migration status • Product containers • SPM Schemes management • One or Multiple Swift Packages • Using SPM products in Cocoapods • Cyclic dependencies between languages Migration challenges
47. Using SPM modules inside Cocoapods Can we do this? 📦 features Package 📲 XING App 🟦 Pod.xcodeProj MyCPModule Common https://github.com/CocoaPods/CocoaPods/pull/11953 💥
48. Using SPM modules inside Cocoapods Yes, we can
49. Using SPM modules inside Cocoapods And that’s how we do it
50. Using SPM modules inside Cocoapods How to create .xcframeworks swift package generate-xcodeproj xcodebuild archive xcodebuild -create-xcframework Swift 5.8 Create Xcode Project from .podspec xcodebuild archive xcodebuild -create-xcframework Swift 5.9
51. • Module migration status • Product containers • SPM Schemes management • One or Multiple Swift Packages • Using SPM products in Cocoapods • Cyclic dependencies between languages Migration challenges
52. Cyclic dependencies between languages
53. Cyclic dependencies between languages Not allowed!
54. Conclusions
55. Conclusions • De f ining more than one package helps to create good practices boundaries for your internal modules • Having a roadmap before starting helps to convince your team and management • Build time was not reduced by using only SPM, but because we improved f irst our architecture • Gradual migration helps us to not having unexpected surprises
56. Evolution and status
57. $ bundle exec pod deintegrate
58. Thanks to all our mates Markus Faßbender Shammi Didla Andreas Koslowski Mark Schütte Özgün Zor Eslam Foad Akshay Shetty