Unit test AnnualStatsAggregationService
epic-annual-impact-summary-core-services-task-014 — Write comprehensive unit tests for AnnualStatsAggregationService covering: correct total hours computation across activity types, unique contact deduplication, activity type distribution normalisation summing to 100%, streak calculation with gaps, offline cache fallback behaviour, and period boundary handling (rolling 12 months vs half-year). Use flutter_test with mock Supabase client and mock cache repository. Target 90%+ branch coverage.
Acceptance Criteria
Technical Requirements
Execution Context
Tier 5 - 253 tasks
Can start after Tier 4 completes
Implementation Notes
If AnnualStatsAggregationService uses DateTime.now() internally, inject a Clock or DateTimeProvider abstraction so tests can control the current time deterministically. For floating-point distribution assertions use closeTo(expected, 0.1) matcher rather than exact equality. When testing streak logic, build activity lists using a helper factory that generates records N days apart — this keeps test data readable. For offline fallback, verify both that the Supabase mock was called once and then the cache mock was called once (interaction verification, not just return value).
Ensure the mock setup mirrors the actual SupabaseClient interface used in production code to avoid false passes.
Testing Requirements
Pure unit tests using flutter_test. Use Mockito (@GenerateMocks) or hand-written fakes for SupabaseClient and CacheRepository. Organise tests in group() blocks: 'total hours', 'contact deduplication', 'distribution normalisation', 'streak calculation', 'offline fallback', 'period boundaries'. Each group should have at least 3 test cases including happy path, edge case, and error case.
Use setUp() for shared fixture construction. Avoid test interdependencies. Run `flutter test --coverage` and verify lcov report shows ≥90% branch coverage on the service file.
Activity records may contain duplicate entries (as evidenced by the duplicate-detection feature dependency) or proxy-registered activities that should be attributed differently. Including duplicates or mis-attributed records would produce inflated stats, undermining trust in the summary.
Mitigation & Contingency
Mitigation: Implement the aggregation query to join against the deduplication-reviewed-flag on activity records and filter out unresolved duplicates. Coordinate with the duplicate-detection feature team to confirm the authoritative flag field before implementing the RPC. Include a data-quality warning in the summary when unresolved duplicates are detected.
Contingency: If deduplication state is unreliable at release time, add a prominent disclaimer in the summary UI noting that figures reflect all registered activities and may include duplicates pending review. Track a follow-up task to re-aggregate after deduplication runs.
Each organisation wants to define their own milestone thresholds (e.g., NHF's counting model differs from HLF's certification model). Implementing configurable thresholds may expand scope significantly if the configuration UI is expected in this epic.
Mitigation & Contingency
Mitigation: Scope this epic strictly to the evaluation engine and a hardcoded default threshold set. Define the MilestoneDefinition interface with an organisation_id discriminator so per-org configs can be loaded from the database in a later sprint. Build the admin configuration UI as a separate follow-on task outside this epic.
Contingency: If stakeholders require per-org milestone configuration before launch, deliver a JSON-based configuration file per org as an interim solution, loaded from Supabase storage, until a full admin UI is built.
Android 13+ restricts access to media collections and requires READ_MEDIA_IMAGES permission for gallery saves, while older Android versions use WRITE_EXTERNAL_STORAGE. Handling both permission models correctly across the device matrix is error-prone.
Mitigation & Contingency
Mitigation: Use the permission_handler Flutter package with version-aware permission requests abstracted behind the summary-share-service interface. Write platform-specific unit tests for both Android API levels in the test harness. Test on a minimum of three Android versions (API 29, 32, 34) in CI.
Contingency: If gallery save is broken on specific Android versions at launch, disable the 'Save to gallery' option on affected API levels and surface only clipboard and system share sheet, which require no media permissions.