Unit test a ViewModel exposing StateFlow in a local JVM test
Tests coroutine hygiene and flow collection strategy. A strong answer covers injecting a TestDispatcher, using runTest, collecting emissions in a background scope, and asserting states.
Tests structured concurrency in tests and StateFlow semantics. A strong answer hits four things: inject a TestDispatcher so the ViewModel runs on controllable threads; wrap the test in runTest to skip delays; collect emissions in a background scope or with Turbine; assert the latest value or the emission sequence. Red flag: hardcoding Dispatchers.Main without a Main dispatcher override, using runBlocking instead of runTest, or forgetting that StateFlow deduplicates rapid equal values.
Read the original → developer.android.com
- #android
- #kotlin
- #viewmodel
- #stateflow
- #unit-testing
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