unit-test-android

Deterministic Android unit tests for ViewModel logic are achieved by isolating dependencies through test doubles like fakes or mocks and placing the tests in the module/src/test directory to ensure local execution without device dependencies.

Local unit tests run on the JVM and are placed in module/src/test, while instrumented tests run on a device or emulator and belong in module/src/androidTest, with boundaries enforced to separate pure business logic from Android framework dependencies.

Android unit tests for Kotlin business logic should be placed in module/src/test to ensure they execute locally as pure JVM tests, keeping them isolated from instrumented tests in module/src/androidTest.

Isolate dependencies in Android ViewModel unit tests by injecting fake, stub, or mock test doubles, replacing real Android framework components to ensure test execution remains deterministic and isolated from external states.

Android unit test assertions should follow the Given-When-Then or Arrange-Act-Assert style, ensuring a minimum set of assertions that clearly verify the expected behavior of the Kotlin or Java business logic.

Yes, this approach applies to both Kotlin and Java business logic across typical Android app architectures, enforcing test placement boundaries and dependency isolation for reliable unit-level verification.