Widget unit tests for all dashboard UI components
epic-coordinator-statistics-dashboard-ui-task-015 — Write flutter_test widget tests for StatsSummaryCards, StatsPeriodFilterBar, PeerMentorStatsList, MonthlyActivityBarChart (including data table fallback), ActivityTypeDonutChart, and PersonalStatsView. Tests must verify rendering in loading, data, error, and empty states, and confirm that semantic labels are present on interactive and chart elements. Use mock BLoC states to drive each scenario.
Acceptance Criteria
Technical Requirements
Execution Context
Tier 7 - 84 tasks
Can start after Tier 6 completes
Implementation Notes
Create a shared test_helpers.dart file in the test/ directory that exports: (1) buildTestableWidget() — wraps a widget in MaterialApp + BlocProvider with the mock BLoC, (2) fixture builders for each state variant (e.g., buildLoadedState(), buildErrorState(), buildEmptyState()), (3) a mockBloc factory. This avoids boilerplate repetition across 6 test files. For MonthlyActivityBarChart, test the accessible data table separately from the chart canvas — find the DataTable widget and verify its rows match the input data. For animation-dependent tests (shimmer skeleton), use tester.pump(Duration(milliseconds: 500)) rather than pumpAndSettle() to avoid infinite loops from continuous animations.
Use const constructors in test widgets wherever possible for faster pump times. Add a CI step that runs flutter test --coverage and fails the build if coverage falls below 80% on the dashboard widget files.
Testing Requirements
All tests are flutter_test widget tests using MockBloc from bloc_test. Test structure per widget: one describe/group block per widget, with nested groups for each state (loading, data, error, empty). Each test pumps the widget wrapped in a BlocProvider
Use fakeAsync for debounce tests in StatsPeriodFilterBar. Verify semantic labels using tester.getSemantics(find.byType(WidgetUnderTest)) and expect(...semanticsNode.label...). Use verify(mockBloc.add(any)) from mockito/mocktail to assert correct events are dispatched. Run flutter test --coverage and verify ≥80% line coverage on all tested files.
PeerMentorStatsList must handle rosters of 40+ mentors efficiently. A naive ListView implementation that re-renders all rows on filter change may cause frame drops on mid-range devices, degrading the experience for coordinators managing large chapters.
Mitigation & Contingency
Mitigation: Use ListView.builder with const constructors for row widgets. Profile the list with Flutter DevTools on a release build against a 60-mentor dataset before submitting for review. Implement sort in the BLoC layer, not in the widget.
Contingency: If frame drops persist, introduce pagination (load 20 mentors, scroll to load more) and add a search filter to reduce visible row count in practice.
The ActivityTypeDonutChart must render org-configured activity type labels from the org-labels system. If the terminology provider is not available or returns stale labels, chart segments will display raw key strings instead of human-readable organisation-specific names, confusing coordinators.
Mitigation & Contingency
Mitigation: Always resolve labels through the OrganizationLabelsProvider before passing data to the donut chart widget. Implement a fallback that formats the raw key as a readable string (e.g., 'peer_support' → 'Peer Support') if the provider returns null.
Contingency: If the org-labels system is unavailable, display the formatted fallback label and log a warning. Do not block chart rendering on label resolution — render with fallbacks immediately.
fl_chart widgets do not natively expose semantic labels for individual bars and donut segments. Without explicit Semantics wrappers, VoiceOver and TalkBack users will receive no meaningful chart information, failing accessibility requirements critical for Blindeforbundet and NHF deployments.
Mitigation & Contingency
Mitigation: Wrap each fl_chart widget in a Semantics widget with a descriptive label summarising the chart data. Implement the data table fallback toggle from the start, not as an afterthought. Validate with VoiceOver on iOS and TalkBack on Android during development.
Contingency: If fl_chart's rendering pipeline prevents semantic overlay from working reliably, replace chart widgets with a custom Canvas-based implementation that has full semantic control, or use a different charting library with better accessibility support.
The period filter state must be preserved when navigating away from the dashboard (e.g., drilling into a mentor's detail screen and pressing back). If the BLoC is re-created on navigation, the filter resets to default, forcing coordinators to re-select their period every time they drill down, degrading operational workflow efficiency.
Mitigation & Contingency
Mitigation: Provide the StatsBloc at a route level above the dashboard screen using a BlocProvider scoped to the statistics navigation shell, not inside the screen widget itself. Verify persistence with a widget integration test that navigates away and back.
Contingency: If route-level scoping is not achievable within the current navigation architecture, persist the last-used filter to a local session store and restore it on screen re-entry.