Repository testing with fakes in Android Kotlin - Build, Publish & Deploy

Build & Publish - Repository testing with fakes

Performance Impact

Using fakes in repository testing does not affect your app's runtime performance or battery life because these tests run separately from the app on your development machine. However, well-designed fakes help catch bugs early, preventing performance issues in the released app.

Optimization for Smooth Testing

Keep your fake implementations simple and focused on the data your tests need. Avoid complex logic or heavy operations in fakes to keep tests fast and reliable. Fast tests encourage frequent runs, improving code quality without slowing development.

App Bundle Size and Startup Time

Fakes are only used in testing and are not included in your app's release build. Therefore, they have no impact on your app's bundle size or startup time.

iOS vs Android Differences

On Android with Kotlin, repository testing with fakes is commonly done using JUnit and Kotlin classes. On iOS, similar testing uses Swift and XCTest with protocol-based fakes. Both platforms benefit from isolating data sources during tests, but the tools and languages differ.

Store Review Guidelines

Repository testing with fakes is a development practice and does not affect app store submissions directly. However, thorough testing helps ensure your app meets store quality guidelines by reducing crashes and bugs.

Self-Check Question

Your app takes 5 seconds to load this screen. What's likely wrong?

• The repository might be making real network or database calls during tests instead of using fakes, causing delays.
• Tests or app code may be blocking the main thread with heavy operations.

Key Result

Using fakes in repository testing improves code quality without impacting app performance or size, enabling faster development cycles and smoother app behavior in production.