Unit Tests: Admin Statistics Service
epic-admin-portal-core-services-task-017 — Write unit tests for AdminStatisticsService covering: all five KPI computations with mocked repository data, subtree scoping correctness, month-over-month trend direction and magnitude, and cache TTL behaviour. Include edge cases for empty orgs and orgs with no activity in the previous month.
Acceptance Criteria
Technical Requirements
Execution Context
Tier 4 - 323 tasks
Can start after Tier 3 completes
Implementation Notes
If AdminStatisticsService does not currently accept a clock/DateTime injection, coordinate with the implementation owner to add a ClockProvider parameter before writing cache TTL tests — avoid using real async delays (Future.delayed) in tests. For trend calculation edge cases, confirm with the team what the API contract is for 'previous month = 0' (division by zero): document this as a comment in the test regardless of outcome. Test subtree scoping by providing mock getSubtreeIds responses that return a specific list of IDs, then assert the repository's fetchActivities call receives exactly those IDs (via verify). Keep test data minimal — a handful of OrgNode stubs and a small set of activity records is sufficient; avoid generating large synthetic datasets that obscure intent.
Testing Requirements
Pure Dart unit tests (flutter_test). Mock AdminStatisticsRepository and OrgHierarchyService using mocktail. Use a FakeClock or injected DateTime for TTL tests to avoid real time delays. Organise in groups: 'KPI computations', 'subtree scoping', 'trend calculations', 'cache behaviour', 'edge cases'.
Each KPI should have its own dedicated test for clarity. Trend calculation tests should use fixed numeric inputs and assert exact output to catch rounding regressions. Run coverage report and enforce ≥ 85% branch coverage on the service class in CI.
OrgHierarchyNavigator rendering NHF's full 1,400-chapter tree in a single widget may cause Flutter frame-rate drops below 60 fps on mid-range devices, making the navigator unusable for NHF national admins.
Mitigation & Contingency
Mitigation: Implement lazy expansion: only load immediate children on node expand rather than the full tree upfront. Use virtual scrolling for long sibling lists. Test with a synthetic 1,400-node dataset on a low-end Android device during development.
Contingency: If lazy expansion is insufficient, replace the tree widget with a paginated drill-down navigator (select level → select child) that avoids rendering more than 50 nodes at a time.
Bufdir may update their required export column structure or file format during or after development. If the AdminExportService hardcodes the current Bufdir schema, any format change requires a code release rather than a config update.
Mitigation & Contingency
Mitigation: Drive the Bufdir column mapping from a configuration repository rather than hardcoded constants. Abstract column definitions into a named schema config so that format changes require only a config update and re-deployment without service logic changes.
Contingency: If Bufdir format changes post-launch, release a config update within one sprint. If the change is structural (new required sections), scope a targeted service update and communicate timeline to partner organisations.
Role transition side-effects in UserManagementService (e.g., certification expiry removing mentor from chapter listing, pause triggering coordinator notification) may interact with external services like HLF's website sync. Incomplete side-effect handling could leave the system in an inconsistent state.
Mitigation & Contingency
Mitigation: Model side-effects as explicit domain events published after the primary state change is persisted. Implement event handlers as idempotent operations so re-processing is safe. Write integration tests that assert all side-effects fire correctly for each role transition type.
Contingency: If a side-effect fails after the primary change is persisted, log the failure with full context and trigger a manual reconciliation alert to the on-call team. Provide an admin-accessible re-trigger action for failed side-effects.
If AdminStatisticsService cache TTL is set too long, org_admin may see significantly stale KPI values (e.g., a mentor newly paused an hour ago still appears as active), undermining trust in the dashboard.
Mitigation & Contingency
Mitigation: Default cache TTL to 5 minutes with a manual refresh action on the dashboard. Implement cache invalidation triggered by UserManagementService write operations that affect counted entities.
Contingency: If staleness causes org admin complaints post-launch, reduce TTL to 60 seconds and introduce a real-time Supabase subscription for high-impact counters (paused mentors, expiring certifications).