Implement ClaimReceiptRepository CRUD operations
epic-receipt-capture-and-attachment-core-logic-task-001 — Create the ClaimReceiptRepository data layer with methods to create, read, update, and delete claim-receipt associations in Supabase. Implement linkReceiptToClaim(), getReceiptsForClaim(), and removeReceiptFromClaim() with proper RLS policies ensuring users can only access their own claim receipts.
Acceptance Criteria
Technical Requirements
Implementation Notes
Follow the existing repository pattern in the codebase: abstract interface (ClaimReceiptRepository) + concrete Supabase implementation (SupabaseClaimReceiptRepository). Inject the SupabaseClient via constructor for testability. The RLS SQL policy for SELECT should be: CREATE POLICY select_own ON claim_receipts FOR SELECT USING (created_by = auth.uid()); similarly for DELETE. For INSERT, use a WITH CHECK instead of USING.
Consider a compound unique constraint on (claim_id, receipt_id) to prevent duplicate links — this also means linkReceiptToClaim can use upsert with onConflict: 'claim_id,receipt_id' for idempotency. Map PostgrestException status codes to domain exceptions in a private _handleError(PostgrestException) method shared across the class.
Testing Requirements
Write unit tests using a mocked SupabaseClient (implement a MockSupabaseClient with mocktail): (1) linkReceiptToClaim returns a ClaimReceipt on success, (2) linkReceiptToClaim throws RepositoryException on PostgrestException with code 23503 (FK violation), (3) getReceiptsForClaim returns empty list when query returns [], (4) removeReceiptFromClaim throws NotFoundException when delete affects 0 rows. Additionally, write an integration test against a local Supabase instance (docker-compose) that verifies RLS blocks a second user from reading or deleting another user's claim_receipts rows.
Run integration tests in CI using the Supabase CLI's local dev stack.
Non-blocking upload creates a race condition: if the claim record is submitted and saved before the upload completes, the storage path may never be written to the claim_receipts table, leaving the claim with a missing receipt that was nonetheless required.
Mitigation & Contingency
Mitigation: Design the attachment service to queue a completion callback that writes the storage path to the claim record upon upload completion, even after the claim form has submitted. Use a local task queue with persistence to survive app backgrounding. Test the race condition explicitly with simulated slow uploads.
Contingency: If the async path association proves unreliable, fall back to blocking upload before claim submission with a clear progress indicator, accepting the UX trade-off in exchange for data integrity.
The offline capture requirement (cache locally, sync when connected) significantly increases state management complexity. If the offline queue is not durable, receipts captured without connectivity may be lost when the app is killed, causing claim submission failures users are not aware of.
Mitigation & Contingency
Mitigation: Persist the offline upload queue to local storage (e.g., Hive or SQLite) on every state transition. Implement background sync using WorkManager (Android) and BGTaskScheduler (iOS). Scope the initial delivery to online-only flow if offline sync cannot be adequately tested before release.
Contingency: Ship without offline support in the first release, displaying a clear 'Upload requires connection' message. Add offline sync as a follow-on task once the core online flow is validated in production.
The inline bottom sheet presentation within a multi-step wizard can conflict with existing modal navigation and back-button handling, particularly if the expense wizard itself uses nested navigation or custom route management.
Mitigation & Contingency
Mitigation: Review the expense wizard navigation architecture before implementation. Use showModalBottomSheet with barrier dismissal disabled to prevent accidental dismissal. Coordinate with the expense wizard team on modal stacking behavior and ensure the camera sheet does not interfere with wizard step transitions.
Contingency: If modal stacking causes navigation issues, present the camera sheet as a full-screen dialog using PageRouteBuilder with a transparent barrier, preserving wizard state via the existing Bloc while still appearing inline.