Improving Developer Experience

Tools and Techniques to improve developer experience for iOS apps.

Transcript

1. Improving Developer Experience
2. Krzysztof Zabłocki @merowing_
3. Improving Developer Experience One of the best investments one can make
4. Bad Developer Experience » Wastes time doing things that aren't important » Dealing with bad tooling, architecture or boilerplate » Creates a disconnect between our work and the end result » Makes us inefficient, creates roadblocks in our way » Makes it easy for us to make simple mistakes
5. Good Developer Experience » Allows us to work smart, not hard » Enables more efficient workflow » Easier to keep connected with our work » Keeps focus on what matters and not dealing with our technical stack shortcomings » Limits human mistakes
6. Issue - Retain Cycles
7. Issue - Retain Cycles Apple: Xcode Memory Graph Debugger + Leaks Instrument » Do you trust people to always run those tools and analyze their results before submitting Pull Requests?
8. Issue - Retain Cycles Open Source: LifetimeTracker » How many instances of class X should ever be alive? » Works in Swift and Objective-C » Surface new retain cycle as you create them, not after you've finished the feature
9. Issue - Retain Cycles Open Source: krzysztofzablocki/LifetimeTracker Straighforward integration: class SectionFrontViewController: UIViewController, LifetimeTrackable { static var lifetimeConfiguration = LifetimeConfiguration(maxCount: 1, groupName: "SF VC") override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) { super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil) /// ... trackLifetime() } }
10. Issue - Long iteration cycle
11. Issue - Long iteration cycle
12. Issue - Long iteration cycle Apple: Split up your project into many frameworks » + Improves modular architecture design » Each framework has its own test suite that can run fast » Enables use of playgrounds or small projects » - Longer launch times due to dylib loading » Leverage cocoapods-aminomo plugin or static libs » - Might be complicated to do in existing projects
13. Issue - Long iteration cycle What if you can't split up your project easily? » Free tool: InjectionForXcode » Code Injection for Objective-C and Swift » Its external app you install, no need to unsign your Xcode
14. Issue - Long iteration cycle Open Source: KZPlayground » Both Swift and Objective-C » Custom DSL for exposing control variables (sliders, image pickers, trigger buttons). » Easy to add Framework to existing code-base » Works great with InjectionForXcode
16. Issue - Boilerplate
17. Issue - Boilerplate Apple: Derived implementations of Equality / Hashing / Codable » - Lack of control over the generated implementation » Not supportive of non-default cases » - Not a generic solution for Boilerplate maintenace, solves only a small subset of common algorithms
18. Issue - Boilerplate Open Source: Sourcery » Swift code generator, works like a pre-processor » Used in over 30 000 apps » Adds annotation support to Swift language » Allows fine-grained control over the generation » Sourcery can generate any boilerplate code if you can describe the algorithm once
19. Issue - Boilerplate Open Source: Sourcery » Supports 3 different templating languages: Swift, Stencil, and EJS » Bundled with: Equality, Hashing, Codable, Lenses, Mocks, Decorators, LinuxMain, Diffing » Powers up projects like ObjectBox and SwiftMocky » Enables real-time programming of templates » Can be used to generate so much more...
21. Issue - Boilerplate Working with assets? » Open Source SwiftGen » Avoid typos and leverage autocompletion » Ensure all assets are available at compile-time, colors, fonts, storyboards, and localized strings
22. Issue - Testing Comparing objects is absolutely terrible
23. Issue - Testing Comparing objects is absolutely terrible » Open Source Sourcery - property level diffing template » Open Source Difference - Pure function Mirror based diffing »
24. Issue - Testing Simplifying mocking and stubbing in tests » Open Source SwiftyMocky - Sourcery based framework for powerful mocking DSL » Open Source Sourcery - AutoMockable template
25. Issue - Data dependencies
26. Issue - Data dependencies » Design your processing like a pipeline » Protocol at each stage so it's easy to change
27. Issue - Data dependencies » Writing tests for your ViewModel? » Bug report requires specific data? » Replace Model Converter with Fake Models
28. Issue - Data dependencies » Want to see how your whole application reacts to specific data changes but the backend isn't ready? » Easily load external data to the application » Sim ? loading from mac file would be preferred » Device? we need to load from a network server » We need real-time updates
29. Issue - Data dependencies Open Source: KZFileWatchers » Works in Swift and Objective-C » FileWatcher.Local useful for observing local file changes e.g. observe file on the developer desktop. » FileWatcher.Remote can be used to observe files on the web, both Etag headers and Last-Modified-Date are supported.
30. Issue - Data dependencies -> Replace DataProvider with FileWatcher
32. Issue - Data reproduction Having a hard time reproducing bugs? » Always save your data at Data Provider level to file » if the user decides to send a bug report, send those files to the cloud » You can use file watcher provider to load it on another device and re-execute almost all code paths you have » Need more power? leverage unidirectional architecture/view state to implement time travel
34. Issue - Manual Steps
35. Issue - Manual Steps Need to fill out some fields? e.g. login credentials » Use user breakpoints » Data never leaves your machine, no git diffs » Easy to disable
36. Issue - Manual Steps Working on a long-running feature?
37. Issue - Manual Steps Working on a long-running feature? » Build phase script that allows you to create #if branches per developer (e.g. http://goo.gl/cLc4ay) #if merowing showARExperience(StubARData(...)) #endif
38. Summary
39. Summary » Good Developer Experience should be one of the core goals of architecture design » Investing time into improving your team developer experience can yield huge efficiency wins for your business and save the sanity of your developers » If a mythical 10x developer exists it would be the person that makes 10 team members more efficient
40. We're hiring!
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