Unit test MilestoneDetectionService
epic-annual-impact-summary-core-services-task-015 — Write unit tests for MilestoneDetectionService covering: correct threshold crossing detection for all metric types (hours, contacts, streak), newly-unlocked vs previously-held milestone distinction, significance ranking order, description template population with correct values, and handling of zero-value stats (no activities in period). Include edge cases: stats exactly at threshold, multiple milestones crossed simultaneously, empty milestone config. Use flutter_test with mock repositories.
Acceptance Criteria
Technical Requirements
Execution Context
Tier 6 - 158 tasks
Can start after Tier 5 completes
Implementation Notes
Create a MilestoneConfigFactory test helper that produces MilestoneConfig objects for specific thresholds — this avoids coupling test setup to the internal config structure. For ranking order tests, construct at least 4 milestones with distinct significance scores and assert the entire returned list order using containsAllInOrder matcher. For template population tests, assert both that the expected value appears and that the raw placeholder string does NOT appear in the output. If MilestoneDetectionService is a pure function (stateless), tests will be straightforward; if it has repository dependencies, inject fakes via constructor rather than relying on service locators.
Testing Requirements
Pure unit tests using flutter_test. No network or database calls — inject all dependencies via constructor with fakes or Mockito mocks. Organise in group() blocks: 'threshold detection by metric type', 'newly-unlocked vs previously-held', 'significance ranking', 'description template population', 'zero-value and empty config edge cases'. Use parametrised-style tests (e.g., a list of (input, expected) pairs iterated in a loop) for threshold boundary checks to reduce duplication.
Verify ≥85% branch coverage via `flutter test --coverage`.
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.