Implement Claim Events Repository
epic-expense-approval-workflow-coordinator-ui-task-001 — Create the ClaimEventsRepository data layer component that persists and retrieves claim lifecycle events (submission, approval, rejection, escalation) from the Supabase database. Implement CRUD operations with RLS policies ensuring coordinators only access claims within their chapter scope.
Acceptance Criteria
Technical Requirements
Implementation Notes
Define a ClaimEventType enum in the domain layer so the database string values are mapped at the repository boundary — do not leak raw strings into BLoC or UI. Use Supabase's `.from('claim_events').select()` with `.eq('claim_id', id)` and `.order('created_at')`. For RLS: create a Postgres policy referencing a join to `expense_claims` where `chapter_id = (SELECT chapter_id FROM coordinator_profiles WHERE user_id = auth.uid())`. Place the RLS migration SQL in a versioned migration file alongside the repository.
Follow the existing repository pattern in the codebase (abstract interface + concrete Supabase implementation) to keep the architecture consistent and allow easy mocking in tests.
Testing Requirements
Unit tests: mock the Supabase client and verify that each repository method calls the correct table/filter/order chain. Test success path and each failure type (network error, permission denied, not found). Integration tests: spin up a local Supabase instance (or use a test project) and verify RLS — a coordinator JWT for chapter A must receive an empty result set when querying events in chapter B. Test event creation sets coordinator_id from the JWT, not from the payload.
Use flutter_test with a fake/stub SupabaseClient for unit tests. Target 90%+ line coverage on the repository class.
Maintaining multi-select state across paginated list pages is architecturally complex in Flutter with Riverpod/BLoC. If the selection state is stored in the widget tree rather than the state layer, page transitions and list redraws can silently clear selections, causing coordinators to lose their multi-select and re-enter it.
Mitigation & Contingency
Mitigation: Store the selected claim ID set in a dedicated Riverpod StateNotifier outside the paginated list widget tree. The paginated list reads selection state from this provider and does not own it. Selection persists independently of list scroll position or page loads.
Contingency: If cross-page selection proves prohibitively complex, limit bulk selection to the currently visible page (add a clear warning in the UI) and prioritise single-page bulk approval for the initial release.
If a coordinator has the queue open while another coordinator approves claims from the same queue (possible in large organisations with shared chapter coverage), the Realtime update may arrive out of order or be missed during a reconnect, leaving the first coordinator's view stale and allowing them to attempt to approve an already-actioned claim.
Mitigation & Contingency
Mitigation: The ApprovalWorkflowService's optimistic locking (from the foundation epic) will catch the concurrent edit at the database level. The CoordinatorReviewQueueScreen should handle the resulting ConcurrencyException by removing the claim from the local list and showing a brief snackbar: 'This claim was already actioned by another coordinator.'
Contingency: Add a queue staleness indicator (a subtle 'last updated X seconds ago' label) and a manual refresh button as a fallback for coordinators who notice inconsistencies.
The end-to-end test requirement that a peer mentor receives a push notification within 30 seconds of coordinator approval depends on FCM delivery latency, which is outside the application's control and can vary significantly in CI/CD environments.
Mitigation & Contingency
Mitigation: Structure end-to-end tests to verify notification intent (correct FCM payload dispatched, correct Realtime event emitted) rather than actual device delivery timing. Use test doubles for FCM delivery in automated tests and reserve real-device delivery tests for manual pre-release validation.
Contingency: If notification timing requirements must be validated in automation, instrument the ApprovalNotificationService with a test hook that records dispatch timestamps and assert against those rather than actual FCM callbacks.