Unit Tests for ProxyContactListProvider
epic-bulk-and-proxy-registration-foundation-task-009 — Write unit tests for ProxyContactListProvider using flutter_test and Riverpod's ProviderContainer. Cover: initial fetch returning correctly mapped PeerMentorContact list, cache hit preventing a second Supabase call, cache invalidation triggering re-fetch, empty roster returning empty list without error, and Supabase error being surfaced as AsyncError state. Mock the Supabase client and assert RLS-aware query parameters.
Acceptance Criteria
Technical Requirements
Execution Context
Tier 3 - 413 tasks
Can start after Tier 2 completes
Implementation Notes
If ProxyContactListProvider uses a repository abstraction (e.g., `IProxyContactRepository`), override the repository provider in ProviderContainer for clean isolation. If it calls Supabase directly, inject a mock via a `supabaseClientProvider` override. For the caching test, ensure the provider uses Riverpod's `keepAlive()` or equivalent caching strategy — if it does not, the cache test should document this as a known limitation rather than falsely passing. For RLS assertion: capture the `.eq()` or `.match()` call arguments on the mock query builder and assert the correct column/value pair.
Use `expectAsync` or `completes` matchers for async state assertions.
Testing Requirements
Use Riverpod's `ProviderContainer` with `overrides` to inject a mock Supabase repository or data source. Do not test Riverpod internals — test the provider's observable state transitions (AsyncLoading → AsyncData / AsyncError). Use `container.listen()` or `container.read()` with `await container.pump()` as appropriate for async providers. Group tests: (1) happy path with data, (2) empty data, (3) error path, (4) caching behaviour, (5) cache invalidation.
Verify mock call counts explicitly for cache tests.
Adding recorded_by_user_id to the activities table and writing correct RLS policies is error-prone: overly permissive policies would allow coordinators to record activities under arbitrary user IDs they do not manage, while overly restrictive policies would silently block valid proxy inserts. A policy defect here would either create a security vulnerability or break the entire proxy feature at runtime.
Mitigation & Contingency
Mitigation: Write RLS policies in a local Supabase emulator first. Include policy unit tests using pg_tap or supabase test helpers. Have a second reviewer check the migration SQL before merging. Explicitly test the three cases: coordinator inserting for their own mentors (should succeed), coordinator inserting for another chapter's mentors (should fail), peer mentor inserting for themselves (should succeed as before).
Contingency: If a policy defect is discovered in staging, roll back the migration with a down-migration script. Delay feature release until the policy is corrected and re-verified. Apply a feature flag to keep the proxy entry point hidden from coordinators until the fix is confirmed.
The insert_bulk_activities RPC must behave atomically — a failure on row 7 of 12 must roll back rows 1–6. If Supabase's RPC transaction handling is misconfigured or if network interruptions cause partial acknowledgements, some peer mentors could receive duplicate or missing activity records, directly corrupting Bufdir statistics for the coordinator's chapter.
Mitigation & Contingency
Mitigation: Implement the RPC as a PostgreSQL function with explicit BEGIN/EXCEPTION/END block to guarantee atomicity. Add an integration test that inserts a batch where one row violates a unique constraint and asserts zero rows are committed. Document the transaction semantics in code comments.
Contingency: If atomicity cannot be guaranteed via RPC (e.g., due to Supabase plan limitations), fall back to a sequential insert loop with a compensating DELETE in case of partial failure, and surface a clear error to the coordinator listing which mentors failed and which succeeded.