viewmodel-testing-expert

What problem does it solve?

This skill provides a structured approach to unit testing Android ViewModels annotated with @HiltViewModel by leveraging Turbine for StateFlow testing, MainDispatcherRule for dispatcher control, and test doubles to simulate repository data.

Core Features & Use Cases

• Test StateFlow emissions: Validate loading, data, and error states in ViewModels using Turbine.
• Dispatcher management: Use MainDispatcherRule (or StandardTestDispatcher) to control coroutines during tests.
• Mock data sources: Drive repository responses with a FakeContentRepository to simulate success, loading, and error paths.
• Pagination and caching patterns: Verify accumulative data, refresh resets, and isFromCache indicators.
• Error handling and UX flows: Confirm error messages, and that errors can be dismissed via onErrorShown.

Quick Start

• Create a test class for your HiltViewModel, apply MainDispatcherRule, and write a Turbine-based test asserting StateFlow transitions using a FakeContentRepository.