Write widget tests for UI primitives
epic-bufdir-report-period-selection-foundation-task-008 — Write Flutter widget tests for PeriodPresetList and CustomDateRangePicker. Tests must verify: preset selection triggers correct callback, empty state renders correctly, invalid date range ordering shows validation error, date range selection updates state correctly, and all interactive elements meet minimum touch target size. Use flutter_test and SemanticsController for accessibility assertions.
Acceptance Criteria
Technical Requirements
Execution Context
Tier 3 - 413 tasks
Can start after Tier 2 completes
Implementation Notes
Wrap each widget in a minimal ProviderScope with stubbed providers — avoid real Supabase calls. Use a FakeAsync or pumpAndSettle for any animated transitions in CustomDateRangePicker. For touch target assertions, find the GestureDetector or InkWell ancestor of each interactive element and assert tester.getSize(finder) >= Size(44, 44). Store semantic test setup in a shared setUp() block to reduce boilerplate.
If the widget uses a Riverpod AsyncValue, test both loading and data states. Prefer finder.first over index-based finders to keep tests resilient to list reordering.
Testing Requirements
Widget tests only (no integration test infrastructure needed). Use flutter_test's WidgetTester. Wrap widgets under test in a MaterialApp + ProviderScope with mocked providers (override periodPresetServiceProvider with a stub). Use SemanticsController (tester.ensureSemantics()) to verify semantic labels.
Use tester.getSize() to assert 44×44dp touch targets. Cover: happy path selection, empty state, invalid range ordering, valid range selection, and touch target sizing. Aim for 100% branch coverage of both widgets.
Supabase RLS policies for period preset configuration may be missing or incorrectly scoped, causing one organisation's presets to leak to another or write operations to fail silently.
Mitigation & Contingency
Mitigation: Define and review RLS policies for the bufdir_period_presets table in the migration file before any repository code is written. Include an integration test that verifies cross-organisation isolation using two distinct org credentials.
Contingency: If RLS is misconfigured in production, immediately disable the period preset fetch endpoint and fall back to hardcoded global presets until the policy is corrected and redeployed.
The activities table may lack a composite index on (organisation_id, activity_date), causing the range count query in BufdirAggregationRepository to perform a full table scan and exceed acceptable response time for large organisations.
Mitigation & Contingency
Mitigation: Add a migration that creates a composite index on (organisation_id, activity_date) as part of this epic. Benchmark the count query against a representative dataset (10 000+ rows) before marking the epic complete.
Contingency: If query latency is unacceptable after indexing, move the count query to a Supabase RPC function that leverages a materialised view or partial index, accepting a slight staleness window.
Flutter's native date picker widgets have known accessibility gaps (missing semantic labels, non-standard focus traversal) that may prevent WCAG 2.2 AA compliance out of the box, requiring a custom implementation.
Mitigation & Contingency
Mitigation: Evaluate third-party accessible date picker packages (e.g., table_calendar with custom semantics) against WCAG 2.2 AA criteria before beginning implementation. Document the chosen approach in the epic kick-off.
Contingency: If no package meets accessibility requirements, implement a simple text-field-based date entry with explicit semantic labels and format hints as an accessible fallback, deferring a fully visual calendar to a later iteration.