In a travel app, a global SessionManager.shared holds auth, cache, analytics, and experiment values all at once, and that makes testing hard. How would you decide what can stay a singleton and what has to move to initializer injection?
Only what truly must be one per process and never needs swapping in tests, like a logger or app bundle info, stays a singleton; anything that needs a different value per test, like login state or experiment values, is defined as a protocol and injected through init.
ArchitectureMultiple choiceBasics
In a codebase where a singleton like AnalyticsManager.shared is referenced directly all…
#singleton #dependency-injection #testability
ArchitectureShort answerIntro
When do you use a singleton in an iOS app, and what's the problem with it?
#singleton #global-state
ArchitectureShort answerBasics
Dependency Injection and the Dependency Inversion Principle have similar names. What's…
#dependency-injection #testability
TestingShort answerBasics
This screen leans heavily on an API response. How would you change the code so you can…
#dependency-injection #testability