name: android-testing-best-practices description: Android testing best practices — Compose UI testing, screenshot tests, Room migrations, CI. user-invocable: true

Android Testing Best Practices

Cross-cutting skill — always activates alongside the project-type-specific skill.

Hard Rules

• •Follow the test pyramid — many unit tests, fewer integration, fewest E2E.
• •Use Compose testing APIs for Compose UI — not Espresso on Compose.
• •Prefer fakes over mocks for dependencies.
• •Export Room schemas (exportSchema = true) and test all migrations.
• •Use descriptive test names that state the scenario and expected outcome.
• •No Thread.sleep() in tests — use idling resources or test coroutine control.
• •Tests must be deterministic — no flaky randomness or timing dependencies.
• •Unit tests run on every PR.
• •Use TestDispatcher + runTest for coroutine tests.
• •Quarantine flaky tests — do not let them block the pipeline.

Core Patterns

• •One concept per test — single assertion focus.
• •AAA structure (Arrange, Act, Assert) in every test.
• •Use test data builders or fixtures, not inline object construction.
• •Test all UI states: loading, content, error, empty.
• •Use Robolectric for fast on-JVM Android tests when instrumented tests aren't needed.
• •Separate test source sets: test/ (unit), androidTest/ (instrumented).

References

• •references/compose_ui_testing.md
• •references/screenshot_testing.md
• •references/instrumented_testing.md
• •references/room_migration_testing.md
• •references/test_architecture.md
• •references/ci_testing.md
• •references/test_fixtures.md