Android Testing Standards

Priority: P0 (CRITICAL)

Qualitative reasoning framework to evaluate unit test value:

Protection against Regressions: Catches real defects; a test passing during failure offers zero protection.
Resistance to Refactoring: Decoupled from internal implementation; zero false alarms on internal refactorings.
Fast Feedback: Executes in milliseconds; rapid local TDD feedback loop.
Maintainability: Clean AAA structure, high readability, zero boilerplate duplication. Avoid inventing arbitrary numeric scores (e.g. P * R * F * M) statically without empirical measurement.

[MOB-TEST-01] Tripartite Naming: Name tests Method_Scenario_ExpectedBehavior (e.g. submitOrder_whenCreditLimitExceeded_displaysBlockedBanner).
[MOB-TEST-02] State & ViewModel Invariant Rule: Assert UI state transitions (e.g. StateFlow/UiState via Turbine test {}); ban asserting 30-property boilerplate state copies.
[MOB-TEST-03] Entity Invariant & Serialization Rule: Test calculations, validations, domain invariants, and non-trivial serialization/parsing or error mapping. Ban testing auto-generated code, trivial getters, or echo tests repeating literal assignments.
[MOB-TEST-04] Contract Testing Rule: Repositories and data sources must be tested for contract compliance and error mapping. Ban 1:1 pass-through mock echoing (coEvery { dataSource.get() } returns x; repo.get() == x).
[MOB-TEST-05] Bug-First Regression Lock: Every PR fixing a bug ticket or with title fix(...) must introduce a failing test reproducing the defect before fixing it.