Implement feature flag application and TenantSessionStore persistence
epic-organization-selection-and-onboarding-core-logic-task-007 — Implement the final two orchestration steps in TenantContextService: apply the org's feature flags via FeatureFlagProvider, and persist the selected org_id to TenantSessionStore (secure storage). TenantContextService becomes the single source of truth for active tenant state, exposing a currentTenant stream consumed by the rest of the app.
Acceptance Criteria
Technical Requirements
Execution Context
Tier 3 - 413 tasks
Can start after Tier 2 completes
Implementation Notes
Model TenantState as a sealed class or freezed union: TenantState.loading / TenantState.active(orgId, featureFlags) / TenantState.none / TenantState.error(exception). Use a StreamController.broadcast() or Riverpod AsyncNotifier for currentTenant. The load() method must follow a strict sequence: (1) validate org, (2) seed labels, (3) apply branding, (4) apply feature flags, (5) persist org_id — any step failure must not advance to step 5. Use a Mutex or similar guard (package:synchronized) to prevent re-entrant load() calls.
For TenantSessionStore, wrap flutter_secure_storage with a typed interface so tests can inject a fake. Feature flags should be cached in memory after application — do not re-fetch on every navigation event. Document the currentTenant stream contract clearly: null emission means 'loading', never 'no tenant'.
Testing Requirements
Unit tests: TenantContextService with mocked FeatureFlagProvider and TenantSessionStore — verify flag application order, persistence call sequencing, and rollback on partial failure. Test idempotency of load() under concurrent calls. Integration tests: verify org_id round-trips correctly through flutter_secure_storage on both iOS simulator (Keychain) and Android emulator (Keystore). Widget tests: verify downstream Riverpod consumers receive updated TenantState after load().
Edge case tests: storage write failure → error state emitted, no org_id persisted; FeatureFlagProvider throws → rollback, no persistence; cold start re-hydration from persisted org_id. Target 90%+ branch coverage on TenantContextService.
TenantContextService must invalidate all downstream Riverpod providers when the org context changes (org switch scenario). If any provider caches org-specific data without subscribing to the tenant context, it will serve stale data from the previous org after a switch — which is both a UX failure and a potential GDPR violation.
Mitigation & Contingency
Mitigation: Define a single TenantContextProvider at the root of the Riverpod provider graph that all org-scoped providers depend on via ref.watch(). When TenantContextService.seedContext() runs, it invalidates TenantContextProvider which cascades invalidation to all dependents. Document this pattern in an architectural decision record so all developers follow it.
Contingency: Implement a post-switch integrity check that re-fetches a sample of each major data entity type and confirms the returned org_id matches the newly selected context; surface a reload prompt if any mismatch is detected.
MultiOrgMembershipResolver must query role assignments across potentially multiple tenant schemas. The anon or authenticated Supabase RLS policy may not permit cross-schema queries, making it impossible to return the full list of orgs a user belongs to in a single call.
Mitigation & Contingency
Mitigation: Design the membership query to use a dedicated Supabase edge function or a shared public schema view that aggregates role assignments across tenant schemas with a service-role key, returning only the org IDs the calling user is permitted to see. This keeps the client read-only.
Contingency: If cross-schema queries cannot be made safely, fall back to a per-org sequential membership check using the list of known org IDs and coalesce results client-side with appropriate timeout handling.
go_router redirect guards behave differently on web vs. mobile for deep links and browser back-button navigation. If the app is later deployed as a Progressive Web App (PWA) for admin use, the OrgRouteGuard may loop or fail to apply correctly on browser navigation events.
Mitigation & Contingency
Mitigation: Implement the guard as a GoRouter.redirect callback (not a ShellRoute redirect) following go_router best practices for platform-agnostic guards. Write widget tests that simulate navigation with and without auth/org context on both mobile and web target platforms in CI.
Contingency: If web-specific guard behaviour differs unacceptably, introduce a platform check in the guard and apply separate redirect logic branches for web vs. mobile until a unified solution is found.
In Phase 2 the OrgSelectionService will need to coordinate the handoff to BankID/Vipps authentication after the org is selected, storing the returned personnummer against the correct tenant's member record. If the service is designed too narrowly for Phase 1 email/password flow, retrofitting Phase 2 will require invasive changes to an already-tested component.
Mitigation & Contingency
Mitigation: Design OrgSelectionService with an AuthHandoffStrategy interface from the start (Phase 1 implementation: email/password, Phase 2: BankID/Vipps). The strategy pattern makes the Phase 2 swap an additive change rather than a rewrite. Stub the interface in Phase 1 with a TODO comment referencing the Phase 2 epic.
Contingency: If Phase 2 requirements diverge significantly from Phase 1 assumptions, create a dedicated Phase2OrgSelectionService subclass that extends the base and overrides the auth handoff step, preserving Phase 1 behaviour unchanged.