A whole lot of stuff

test/ad_free_upsell_dialog_test.dart

@@ -0,0 +1,69 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:provider/provider.dart';
+
+import 'package:fuel_tax_tracker/services/app_state.dart';
+import 'package:fuel_tax_tracker/widgets/ad_free_upsell_dialog.dart';
+
+/// Covers the "remove ads for a year" upsell shown right after a user
+/// watches the app's one ad placement — see `AppState.syncNow`'s
+/// `onAdWatched` hook, wired up in main.dart. Tested here as a standalone
+/// dialog function, matching backup_reminder_test.dart's convention.
+void main() {
+  Future<void> openDialog(WidgetTester tester, AppState appState) async {
+    await tester.pumpWidget(
+      ChangeNotifierProvider.value(
+        value: appState,
+        child: MaterialApp(
+          home: Builder(
+            builder: (context) => ElevatedButton(
+              onPressed: () => showAdFreeUpsellDialog(context),
+              child: const Text('open'),
+            ),
+          ),
+        ),
+      ),
+    );
+    await tester.tap(find.text('open'));
+    await tester.pumpAndSettle();
+  }
+
+  testWidgets('shows the pitch with both actions', (tester) async {
+    await openDialog(tester, AppState());
+
+    expect(find.text('Tired of Ads?'), findsOneWidget);
+    expect(find.text('Not Now'), findsOneWidget);
+    expect(find.text('Remove Ads'), findsOneWidget);
+  });
+
+  testWidgets('falls back to generic copy when no price is loaded yet', (tester) async {
+    await openDialog(tester, AppState());
+
+    expect(find.textContaining('a single one-time purchase'), findsOneWidget);
+    expect(find.textContaining('\$'), findsNothing);
+  });
+
+  testWidgets('Not Now closes the dialog without navigating anywhere', (tester) async {
+    await openDialog(tester, AppState());
+
+    await tester.tap(find.text('Not Now'));
+    await tester.pumpAndSettle();
+
+    expect(find.text('Tired of Ads?'), findsNothing);
+  });
+
+  testWidgets('Remove Ads closes the dialog and starts the purchase flow', (tester) async {
+    final appState = AppState();
+    await openDialog(tester, appState);
+
+    await tester.tap(find.text('Remove Ads'));
+    await tester.pumpAndSettle();
+
+    expect(find.text('Tired of Ads?'), findsNothing, reason: 'dialog closed');
+    // buyAdFreeYear() delegates to PurchaseService, which — with no real
+    // store connection in tests — surfaces its failure through
+    // AppState.purchaseError rather than throwing, so tapping through is
+    // enough to confirm the button actually invoked it without crashing.
+    expect(appState.purchaseError, isNotNull);
+  });
+}

test/backup_reminder_test.dart

@@ -4,6 +4,7 @@ import 'package:provider/provider.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 
 import 'package:fuel_tax_tracker/screens/data_settings_screen.dart';
+import 'package:fuel_tax_tracker/screens/faq_screen.dart';
 import 'package:fuel_tax_tracker/services/app_state.dart';
 import 'package:fuel_tax_tracker/services/cloud/cloud_storage_provider.dart';
 import 'package:fuel_tax_tracker/services/cloud_sync_service.dart';
@@ -44,10 +45,40 @@ void main() {
       await openDialog(tester);
 
       expect(find.text("Your Data Isn't Backed Up"), findsOneWidget);
+      expect(find.text('Learn More'), findsOneWidget);
       expect(find.text('Not Now'), findsOneWidget);
       expect(find.text('Set Up Backup'), findsOneWidget);
     });
 
+    testWidgets('Learn More resolves false, closes the dialog, and opens the FAQ to the '
+        'backup question', (tester) async {
+      bool? result;
+      await tester.pumpWidget(
+        MaterialApp(
+          home: Builder(
+            builder: (context) => ElevatedButton(
+              onPressed: () async => result = await showBackupReminderDialog(context),
+              child: const Text('open'),
+            ),
+          ),
+        ),
+      );
+      await tester.tap(find.text('open'));
+      await tester.pumpAndSettle();
+
+      await tester.tap(find.text('Learn More'));
+      await tester.pumpAndSettle();
+
+      expect(result, isFalse);
+      expect(find.text("Your Data Isn't Backed Up"), findsNothing, reason: 'dialog closed');
+      expect(find.byType(FaqScreen), findsOneWidget);
+
+      await tester.scrollUntilVisible(find.text('Is my data backed up?'), 300,
+          scrollable: find.byType(Scrollable));
+      expect(find.textContaining('Not by default'), findsOneWidget,
+          reason: 'backup question starts expanded');
+    });
+
     testWidgets('Not Now resolves false and closes the dialog', (tester) async {
       bool? result;
       await tester.pumpWidget(

test/cloud_sync_service_test.dart

@@ -180,10 +180,14 @@ void main() {
       syncService.configure('app-folder-id');
 
       final result = await syncService.syncNow(
-        beforeUpload: () async => calls.add('beforeUpload'),
+        beforeUpload: () async {
+          calls.add('beforeUpload');
+          return true;
+        },
       );
 
       expect(result.ranSync, isTrue);
+      expect(result.adGateBlocked, isFalse);
       expect(calls.first, 'download', reason: 'pull/merge happens first');
       expect(calls[1], 'beforeUpload');
       // Everything after beforeUpload is an upload (the data-file push,
@@ -200,12 +204,39 @@ void main() {
       final syncService = CloudSyncService(provider: provider, databaseService: databaseService);
       syncService.configure('app-folder-id');
 
-      await syncService.syncNow(beforeUpload: () async => calls.add('beforeUpload'));
+      await syncService.syncNow(
+        beforeUpload: () async {
+          calls.add('beforeUpload');
+          return true;
+        },
+      );
 
       expect(calls.first, 'beforeUpload');
       expect(calls, contains('upload:$dataFileName'));
     });
 
+    test('a false return blocks the upload but keeps whatever was already pulled/merged',
+        () async {
+      final calls = <String>[];
+      final remoteDbBytes = await File(databaseService.databasePath).readAsBytes();
+      final session = _FakeSession();
+      session.existingDataFile = CloudFileInfo(id: 'remote-db-id', versionTag: 'remote-v1');
+      session.remoteDbBytes = remoteDbBytes;
+      session.onDownload = () => calls.add('download');
+      session.onUpload = (name) => calls.add('upload:$name');
+      final provider = _FakeProvider(session);
+      final syncService = CloudSyncService(provider: provider, databaseService: databaseService);
+      syncService.configure('app-folder-id');
+
+      final result = await syncService.syncNow(beforeUpload: () async => false);
+
+      expect(result.ranSync, isFalse);
+      expect(result.adGateBlocked, isTrue);
+      expect(calls, ['download'], reason: 'pull/merge still ran; nothing was uploaded');
+      expect(session.deletedFileIds, ['lock-id'],
+          reason: 'the lock must still be released when the gate blocks the upload');
+    });
+
     test('omitting it changes nothing — every other syncNow call site keeps working', () async {
       final session = _FakeSession();
       final provider = _FakeProvider(session);

test/edit_fuel_entry_test.dart

@@ -23,6 +23,8 @@ import 'package:fuel_tax_tracker/services/database_service.dart';
 /// other upsert in this app (see [DatabaseService.saveVehicle]).
 void main() {
   final vehicle = Vehicle(id: 'v1', vin: '1FMPU18L1TLB51349', updatedAt: DateTime.utc(2026, 1, 1));
+  final otherVehicle =
+      Vehicle(id: 'v2', vin: '1HGCM82633A004352', nickname: 'Second Car', updatedAt: DateTime.utc(2026, 1, 1));
   final entry = FuelEntry(
     id: 'e1',
     vehicleId: 'v1',
@@ -83,6 +85,25 @@ void main() {
       final rawRow = (await database.rawDb.query('fuel_entries', where: 'id = ?', whereArgs: ['e1'])).single;
       expect(rawRow['dirty'], 1);
     });
+
+    test('saving again with a different vehicleId moves the entry to that vehicle', () async {
+      await database.saveVehicle(vehicle);
+      await database.saveVehicle(otherVehicle);
+      await database.saveFuelEntry(entry);
+
+      await database.saveFuelEntry(FuelEntry(
+        id: entry.id,
+        vehicleId: otherVehicle.id,
+        date: entry.date,
+        gallons: entry.gallons,
+        pricePerGallon: entry.pricePerGallon,
+        totalCost: entry.totalCost,
+        updatedAt: DateTime.utc(2026, 3, 6),
+      ));
+
+      final saved = (await database.getFuelEntries()).single;
+      expect(saved.vehicleId, otherVehicle.id);
+    });
   });
 
   group('EditFuelEntryScreen', () {
@@ -142,6 +163,50 @@ void main() {
       expect(find.text('Required'), findsOneWidget);
       expect(find.byType(EditFuelEntryScreen), findsOneWidget, reason: 'did not navigate away');
     });
+
+    testWidgets('shows a vehicle picker pre-selected to the entry\'s current vehicle',
+        (tester) async {
+      final appState = AppState()
+        ..isLoading = false
+        ..vehicles = [vehicle, otherVehicle]
+        ..fuelEntries = [entry];
+
+      await tester.pumpWidget(
+        ChangeNotifierProvider.value(
+          value: appState,
+          child: MaterialApp(home: EditFuelEntryScreen(entry: entry)),
+        ),
+      );
+
+      expect(find.widgetWithText(DropdownButtonFormField<String>, vehicle.displayLabel),
+          findsOneWidget);
+    });
+
+    testWidgets('picking a different vehicle updates the selection shown', (tester) async {
+      final appState = AppState()
+        ..isLoading = false
+        ..vehicles = [vehicle, otherVehicle]
+        ..fuelEntries = [entry];
+
+      await tester.pumpWidget(
+        ChangeNotifierProvider.value(
+          value: appState,
+          child: MaterialApp(home: EditFuelEntryScreen(entry: entry)),
+        ),
+      );
+
+      await tester.tap(find.byType(DropdownButtonFormField<String>));
+      await tester.pumpAndSettle();
+      // Two matches once the menu is open: the closed field's current
+      // selection, and the same label repeated as a menu item.
+      await tester.tap(find.text(otherVehicle.displayLabel).last);
+      await tester.pumpAndSettle();
+
+      expect(find.widgetWithText(DropdownButtonFormField<String>, otherVehicle.displayLabel),
+          findsOneWidget);
+      expect(find.widgetWithText(DropdownButtonFormField<String>, vehicle.displayLabel),
+          findsNothing);
+    });
   });
 }
 

test/estimated_refund_test.dart

@@ -0,0 +1,29 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:fuel_tax_tracker/services/estimated_refund.dart';
+
+void main() {
+  test('the rate itself is 12.5 cents per gallon', () {
+    expect(moHighwayFuelTaxRefundRatePerGallon, 0.125);
+  });
+
+  test('multiplies whole gallons by the rate', () {
+    expect(estimatedFuelRefund(10), 1.25);
+    expect(estimatedFuelRefund(20), 2.50);
+    expect(estimatedFuelRefund(0), 0);
+  });
+
+  test('rounds fractional gallons to the nearest whole gallon before multiplying', () {
+    // 10.523 rounds up to 11 gallons: 11 * $0.125 = $1.375, floored to $1.37.
+    expect(estimatedFuelRefund(10.523), 1.37);
+    // 10.4 rounds down to 10 gallons: 10 * $0.125 = $1.25 exactly.
+    expect(estimatedFuelRefund(10.4), 1.25);
+  });
+
+  test('rounds the resulting cents down, never up', () {
+    // 1 gallon * $0.125 = $0.125 — rounding to the nearest cent would give
+    // $0.13, but this must floor to $0.12 instead.
+    expect(estimatedFuelRefund(1), 0.12);
+    // 3 gallons * $0.125 = $0.375 — floors to $0.37, not $0.38.
+    expect(estimatedFuelRefund(3), 0.37);
+  });
+}

test/faq_screen_test.dart

@@ -0,0 +1,104 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:fuel_tax_tracker/screens/faq_screen.dart';
+
+/// Covers [FaqScreen] itself (question list, collapsed-by-default,
+/// deep-linking a specific entry open) and [FaqActionButton], the shared
+/// "?" AppBar action reused across every tab — see settings_screen_test.dart
+/// for the Settings landing page's own FAQ entry, and
+/// backup_reminder_test.dart for the "Learn More" link into a specific
+/// entry.
+void main() {
+  testWidgets('every question starts collapsed with no initiallyExpandedQuestion given',
+      (tester) async {
+    await tester.pumpWidget(const MaterialApp(home: FaqScreen()));
+
+    expect(find.text('What is the Missouri Motor Fuel Tax Refund?'), findsOneWidget);
+    expect(find.textContaining('12.5¢ per gallon'), findsNothing);
+  });
+
+  testWidgets('groups questions under section headers', (tester) async {
+    await tester.pumpWidget(const MaterialApp(home: FaqScreen()));
+
+    // The first section header is visible without scrolling; the last
+    // one only reachable by scrolling all the way down — checking both
+    // confirms headers span the whole list, not just its start.
+    expect(find.text('Missouri Motor Fuel Tax Refund'), findsOneWidget);
+
+    await tester.scrollUntilVisible(find.text('Advertisements'), 300,
+        scrollable: find.byType(Scrollable));
+    expect(find.text('Advertisements'), findsOneWidget);
+  });
+
+  testWidgets('tapping a question expands its answer', (tester) async {
+    await tester.pumpWidget(const MaterialApp(home: FaqScreen()));
+
+    await tester.scrollUntilVisible(find.text('How do I remove ads?'), 300,
+        scrollable: find.byType(Scrollable));
+    // scrollUntilVisible stops as soon as any part is on-screen, which can
+    // leave it right at the bottom edge — nudge further so its center
+    // (what tap() targets) is comfortably inside the viewport.
+    await tester.drag(find.byType(Scrollable), const Offset(0, -100));
+    await tester.pumpAndSettle();
+    await tester.tap(find.text('How do I remove ads?'));
+    await tester.pumpAndSettle();
+
+    expect(find.textContaining("doesn't auto-renew"), findsOneWidget);
+  });
+
+  testWidgets('includes a contact email for problem receipts/VINs/errors', (tester) async {
+    await tester.pumpWidget(const MaterialApp(home: FaqScreen()));
+
+    await tester.scrollUntilVisible(
+        find.text("Found a receipt, VIN, or error the app couldn't handle?"), 300,
+        scrollable: find.byType(Scrollable));
+    await tester.tap(find.text("Found a receipt, VIN, or error the app couldn't handle?"));
+    await tester.pumpAndSettle();
+
+    expect(find.textContaining('ohbrer+ShowMeTheFuelRefund@gmail.com'), findsOneWidget);
+  });
+
+  testWidgets('the refund program question covers both highway and non-highway refunds',
+      (tester) async {
+    await tester.pumpWidget(const MaterialApp(home: FaqScreen()));
+
+    await tester.tap(find.text('What is the Missouri Motor Fuel Tax Refund?'));
+    await tester.pumpAndSettle();
+
+    expect(find.textContaining('Highway use — up to 12.5¢ per gallon'), findsOneWidget);
+    expect(find.textContaining('Non-highway use — up to 29.5¢ per gallon'), findsOneWidget);
+    expect(find.textContaining("isn't tax advice"), findsOneWidget);
+    expect(find.textContaining('consult a tax professional'), findsOneWidget);
+  });
+
+  testWidgets('initiallyExpandedQuestion starts that one entry open, others collapsed',
+      (tester) async {
+    await tester.pumpWidget(
+      const MaterialApp(home: FaqScreen(initiallyExpandedQuestion: 'Is my data backed up?')),
+    );
+    await tester.pumpAndSettle();
+
+    // Its section (Data Safety) is further down the page now that
+    // questions are grouped — scroll to it before checking its content.
+    await tester.scrollUntilVisible(find.text('Is my data backed up?'), 300,
+        scrollable: find.byType(Scrollable));
+
+    expect(find.textContaining('Not by default'), findsOneWidget);
+    expect(find.textContaining('12.5¢ per gallon'), findsNothing,
+        reason: 'only the targeted question starts expanded');
+  });
+
+  testWidgets('FaqActionButton pushes FaqScreen', (tester) async {
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Scaffold(appBar: AppBar(actions: const [FaqActionButton()])),
+      ),
+    );
+
+    await tester.tap(find.byIcon(Icons.help_outline));
+    await tester.pumpAndSettle();
+
+    expect(find.byType(FaqScreen), findsOneWidget);
+  });
+}

test/fuel_report_test.dart

@@ -278,4 +278,35 @@ void main() {
     expect(byMonth[DateTime(2026, 3)]!.map((re) => re.entry.id), ['mar-1']);
     expect(byMonth[DateTime(2026, 4)]!.map((re) => re.entry.id), ['apr-1']);
   });
+
+  group('defaultReportDateRange', () {
+    test('from August through year-end, defaults to July of that year through the following June',
+        () {
+      final (start, end) = defaultReportDateRange(DateTime(2026, 8, 17));
+      expect(start, DateTime(2026, 7, 1));
+      expect(end, DateTime(2027, 6, 30));
+    });
+
+    test('from January through July, still defaults to the July before through this June', () {
+      final (start, end) = defaultReportDateRange(DateTime(2027, 7, 15));
+      expect(start, DateTime(2026, 7, 1));
+      expect(end, DateTime(2027, 6, 30));
+    });
+
+    test('the next cycle (August the following year) rolls the whole range forward a year', () {
+      final (start, end) = defaultReportDateRange(DateTime(2027, 8, 1));
+      expect(start, DateTime(2027, 7, 1));
+      expect(end, DateTime(2028, 6, 30));
+    });
+
+    test('July 31 is still the old cycle; August 1 is the new one', () {
+      final stillOld = defaultReportDateRange(DateTime(2026, 7, 31));
+      expect(stillOld.$1, DateTime(2025, 7, 1));
+      expect(stillOld.$2, DateTime(2026, 6, 30));
+
+      final nowNew = defaultReportDateRange(DateTime(2026, 8, 1));
+      expect(nowNew.$1, DateTime(2026, 7, 1));
+      expect(nowNew.$2, DateTime(2027, 6, 30));
+    });
+  });
 }

test/receipts_screen_test.dart

@@ -65,6 +65,69 @@ void main() {
     expect(find.text('Red Truck'), findsOneWidget);
   });
 
+  testWidgets(
+      'shows an estimated fuel refund in the hero banner and next to each row\'s gallons '
+      'when the setting is on', (tester) async {
+    final entry = FuelEntry(
+      id: 'e1',
+      vehicleId: 'v1',
+      date: DateTime(2026, 5, 14),
+      gallons: 10.523,
+      pricePerGallon: 3.5,
+      totalCost: 32.48,
+      updatedAt: DateTime.utc(2026, 5, 14),
+      receiptDriveFileId: 'remote-1',
+    );
+    final appState = AppState()
+      ..isLoading = false
+      ..vehicles = [vehicle]
+      ..fuelEntries = [entry]
+      ..showEstimatedFuelRefund = true;
+
+    await tester.pumpWidget(
+      ChangeNotifierProvider.value(
+        value: appState,
+        child: const MaterialApp(home: ReceiptsScreen()),
+      ),
+    );
+
+    expect(find.text('Est. Refund'), findsOneWidget, reason: 'replaces the hero icon');
+    // 10.523 gal rounds up to 11, * $0.125/gal = $1.375, floored to $1.37 —
+    // the hero's own standalone stat value...
+    expect(find.text('\$1.37'), findsOneWidget);
+    // ...and the same figure again, folded into the row's combined text.
+    expect(find.textContaining('10.523 gal  ·  Est. \$1.37'), findsOneWidget);
+  });
+
+  testWidgets("doesn't show an estimated fuel refund anywhere when the setting is off (default)",
+      (tester) async {
+    final entry = FuelEntry(
+      id: 'e1',
+      vehicleId: 'v1',
+      date: DateTime(2026, 5, 14),
+      gallons: 10.523,
+      pricePerGallon: 3.5,
+      totalCost: 32.48,
+      updatedAt: DateTime.utc(2026, 5, 14),
+      receiptDriveFileId: 'remote-1',
+    );
+    final appState = AppState()
+      ..isLoading = false
+      ..vehicles = [vehicle]
+      ..fuelEntries = [entry];
+
+    await tester.pumpWidget(
+      ChangeNotifierProvider.value(
+        value: appState,
+        child: const MaterialApp(home: ReceiptsScreen()),
+      ),
+    );
+
+    expect(appState.showEstimatedFuelRefund, isFalse, reason: 'off by default');
+    expect(find.text('Est. Refund'), findsNothing);
+    expect(find.textContaining('Est. \$'), findsNothing);
+  });
+
   testWidgets('tapping a receipted row opens the receipt detail page', (tester) async {
     final entry = FuelEntry(
       id: 'e1',

test/report_vehicle_selection_test.dart

@@ -7,9 +7,11 @@ import 'package:fuel_tax_tracker/models/vehicle.dart';
 import 'package:fuel_tax_tracker/screens/report_screen.dart';
 import 'package:fuel_tax_tracker/services/app_state.dart';
 
-/// Covers the per-vehicle selection cards on the Reports tab: once a date
-/// range is picked, every vehicle with a receipted entry in range starts
-/// selected (colored like the "Share" button), tapping one to deselect it
+/// Covers the per-vehicle selection cards on the Reports tab: with a date
+/// range in place (now defaulted automatically — see
+/// defaultReportDateRange/ReportScreen.initState), every vehicle with a
+/// receipted entry in range starts selected (colored like the "Share"
+/// button), tapping one to deselect it
 /// drops it from the total (and, by extension, the generated report) and
 /// reverts its coloring to a plain unselected card, and deselecting every
 /// vehicle shows a distinct "nothing selected" message rather than "no
@@ -19,10 +21,10 @@ void main() {
   final vehicleA = Vehicle(id: 'a', vin: 'VINAAAAAAAAAAAAAA', nickname: 'Truck', updatedAt: DateTime.utc(2026, 1, 1));
   final vehicleB = Vehicle(id: 'b', vin: 'VINBBBBBBBBBBBBBB', nickname: 'Van', updatedAt: DateTime.utc(2026, 1, 1));
 
-  // showDatePicker's initial date (when none is set yet) defaults to
-  // "now" — dating these entries to "now" too, rather than a fixed date,
-  // means just accepting that default on both pickers (below) already
-  // covers them, without needing to drive the calendar UI to a specific day.
+  // ReportScreen's date range now defaults to the current fuel-tax-refund
+  // period (see defaultReportDateRange) as soon as it opens — dating these
+  // entries to "now" means they always fall inside that default range,
+  // without these tests needing to drive the date pickers themselves.
   final now = DateTime.now();
 
   FuelEntry entryFor(String vehicleId, String id, double gallons, double cost) => FuelEntry(
@@ -36,26 +38,15 @@ void main() {
         receiptDriveFileId: 'remote-$id',
       );
 
-  Future<void> pickRange(WidgetTester tester) async {
-    await tester.tap(find.text('Start date'));
-    await tester.pumpAndSettle();
-    await tester.tap(find.text('OK'));
-    await tester.pumpAndSettle();
-
-    await tester.tap(find.text('End date'));
-    await tester.pumpAndSettle();
-    await tester.tap(find.text('OK'));
-    await tester.pumpAndSettle();
-  }
-
-  Future<AppState> pumpReport(WidgetTester tester) async {
+  Future<AppState> pumpReport(WidgetTester tester, {bool showEstimatedFuelRefund = false}) async {
     final appState = AppState()
       ..isLoading = false
       ..vehicles = [vehicleA, vehicleB]
       ..fuelEntries = [
         entryFor('a', 'e1', 10, 35),
         entryFor('b', 'e2', 20, 70),
-      ];
+      ]
+      ..showEstimatedFuelRefund = showEstimatedFuelRefund;
 
     await tester.pumpWidget(
       ChangeNotifierProvider.value(
@@ -73,7 +64,6 @@ void main() {
   testWidgets('both vehicles start colored as selected once a range with entries for both is picked',
       (tester) async {
     await pumpReport(tester);
-    await pickRange(tester);
 
     final colorScheme = Theme.of(tester.element(find.text('Truck'))).colorScheme;
 
@@ -82,10 +72,28 @@ void main() {
     expect(find.text('30.000 gal · \$105.00'), findsOneWidget, reason: 'combined total');
   });
 
+  testWidgets(
+      'shows an estimated fuel refund below each vehicle\'s total cost and next to the '
+      'combined total, when the setting is on', (tester) async {
+    await pumpReport(tester, showEstimatedFuelRefund: true);
+
+    // Truck: 10 gal * $0.125/gal = $1.25. Van: 20 gal * $0.125/gal = $2.50.
+    expect(find.text('Est. \$1.25'), findsOneWidget);
+    expect(find.text('Est. \$2.50'), findsOneWidget);
+    // Combined: 30 gal * $0.125/gal = $3.75, folded into the Total row.
+    expect(find.text('30.000 gal · \$105.00 · Est. \$3.75'), findsOneWidget);
+  });
+
+  testWidgets('shows no estimated fuel refund anywhere when the setting is off (default)',
+      (tester) async {
+    await pumpReport(tester);
+
+    expect(find.textContaining('Est. \$'), findsNothing);
+  });
+
   testWidgets('tapping a selected vehicle deselects it (reverts its coloring) and drops it from the total',
       (tester) async {
     await pumpReport(tester);
-    await pickRange(tester);
 
     final colorScheme = Theme.of(tester.element(find.text('Truck'))).colorScheme;
 
@@ -100,7 +108,6 @@ void main() {
   testWidgets('tapping a deselected vehicle again reselects it (restores its coloring)',
       (tester) async {
     await pumpReport(tester);
-    await pickRange(tester);
 
     final colorScheme = Theme.of(tester.element(find.text('Truck'))).colorScheme;
 
@@ -113,10 +120,24 @@ void main() {
     expect(find.text('30.000 gal · \$105.00'), findsOneWidget, reason: 'both counted again');
   });
 
+  testWidgets('tapping Preview opens the report preview screen', (tester) async {
+    await pumpReport(tester);
+
+    await tester.scrollUntilVisible(find.text('Preview'), 300, scrollable: find.byType(Scrollable));
+    await tester.tap(find.text('Preview'));
+    // Not pumpAndSettle: PdfPreview's own internal rendering isn't under
+    // test here (no platform channel mocked for it) — just that Preview
+    // actually navigates. A couple of bounded pumps are enough for that
+    // navigation (a synchronous PDF build, no plugin calls) to land.
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 300));
+
+    expect(find.text('Report Preview'), findsOneWidget);
+  });
+
   testWidgets('deselecting every vehicle shows a distinct "nothing selected" message',
       (tester) async {
     await pumpReport(tester);
-    await pickRange(tester);
 
     await tester.tap(find.text('Truck'));
     await tester.pumpAndSettle();
@@ -127,6 +148,7 @@ void main() {
       find.text('No vehicles selected — tap at least one above to build a report.'),
       findsOneWidget,
     );
+    expect(find.text('Preview'), findsNothing);
     expect(find.text('Share'), findsNothing);
     expect(find.text('Print'), findsNothing);
     // The cards themselves stay visible so the user can tap one again.

test/settings_screen_test.dart

@@ -3,8 +3,10 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:provider/provider.dart';
 
 import 'package:fuel_tax_tracker/screens/data_settings_screen.dart';
+import 'package:fuel_tax_tracker/screens/faq_screen.dart';
 import 'package:fuel_tax_tracker/screens/settings_screen.dart';
 import 'package:fuel_tax_tracker/screens/ui_settings_screen.dart';
+import 'package:fuel_tax_tracker/screens/user_agreement_screen.dart';
 import 'package:fuel_tax_tracker/services/app_state.dart';
 
 /// Covers the Settings landing page's menu wiring: it groups settings into
@@ -24,11 +26,15 @@ void main() {
     );
   }
 
-  testWidgets('shows UI and Data menu entries, plus the summary', (tester) async {
+  testWidgets('shows UI, Data, FAQ, and User Agreement menu entries, plus the summary',
+      (tester) async {
     await pumpSettings(tester);
 
     expect(find.text('UI'), findsOneWidget);
     expect(find.text('Data'), findsOneWidget);
+    expect(find.text('FAQ'), findsOneWidget);
+    expect(find.text('User Agreement'), findsOneWidget);
+    await tester.scrollUntilVisible(find.text('Summary'), 300, scrollable: find.byType(Scrollable));
     expect(find.text('Summary'), findsOneWidget);
     // None of Data's contents leaked onto the landing page.
     expect(find.text('Cloud Storage'), findsNothing);
@@ -56,4 +62,45 @@ void main() {
     await tester.scrollUntilVisible(find.text('Advanced'), 200, scrollable: find.byType(Scrollable));
     expect(find.text('Advanced'), findsOneWidget);
   });
+
+  testWidgets('tapping FAQ opens FaqScreen with its questions collapsed by default',
+      (tester) async {
+    await pumpSettings(tester);
+
+    await tester.tap(find.text('FAQ'));
+    await tester.pumpAndSettle();
+
+    expect(find.byType(FaqScreen), findsOneWidget);
+    expect(find.text('What is the Missouri Motor Fuel Tax Refund?'), findsOneWidget);
+    // Answers are inside collapsed ExpansionTiles, not visible until tapped.
+    expect(find.textContaining('12.5¢ per gallon'), findsNothing);
+
+    await tester.tap(find.text('What is the Missouri Motor Fuel Tax Refund?'));
+    await tester.pumpAndSettle();
+
+    expect(find.textContaining('12.5¢ per gallon'), findsOneWidget);
+  });
+
+  testWidgets('tapping User Agreement opens it in review mode (no Decline/I Agree)',
+      (tester) async {
+    await pumpSettings(tester);
+
+    await tester.tap(find.text('User Agreement'));
+    await tester.pumpAndSettle();
+
+    expect(find.byType(UserAgreementScreen), findsOneWidget);
+    expect(find.widgetWithText(FilledButton, 'I Agree'), findsNothing);
+    expect(find.widgetWithText(OutlinedButton, 'Decline'), findsNothing);
+  });
+
+  testWidgets('Ads card offers both buying and restoring when ads are not disabled',
+      (tester) async {
+    await pumpSettings(tester);
+
+    // Not tapped — buyAdFreeYear/restoreAdFreeYear reach a real platform
+    // channel via PurchaseService, which isn't set up in this test; only
+    // confirming both entry points render.
+    expect(find.widgetWithText(FilledButton, 'Remove Ads for a Year'), findsOneWidget);
+    expect(find.widgetWithText(TextButton, 'Restore Purchase'), findsOneWidget);
+  });
 }

test/theme_toggle_test.dart

@@ -61,4 +61,43 @@ void main() {
     // already-persisted user settings by renaming it there.
     expect(prefs.getString('theme_mode'), 'dark');
   });
+
+  group('Estimated Fuel Refund toggle', () {
+    testWidgets('off by default, flips on and persists when tapped', (tester) async {
+      final appState = AppState()..isLoading = false;
+
+      await tester.pumpWidget(
+        ChangeNotifierProvider.value(
+          value: appState,
+          child: const MaterialApp(home: UiSettingsScreen()),
+        ),
+      );
+
+      expect(appState.showEstimatedFuelRefund, isFalse);
+      expect(tester.widget<SwitchListTile>(find.byType(SwitchListTile)).value, isFalse);
+
+      await tester.tap(find.text('Estimated Fuel Refund'));
+      await tester.pumpAndSettle();
+
+      expect(appState.showEstimatedFuelRefund, isTrue);
+
+      final prefs = await SharedPreferences.getInstance();
+      expect(prefs.getBool('show_estimated_fuel_refund'), isTrue);
+    });
+
+    testWidgets('explanation mentions the Missouri Highway Fuel Tax Refund and the current rate',
+        (tester) async {
+      final appState = AppState()..isLoading = false;
+
+      await tester.pumpWidget(
+        ChangeNotifierProvider.value(
+          value: appState,
+          child: const MaterialApp(home: UiSettingsScreen()),
+        ),
+      );
+
+      expect(find.textContaining('Missouri Highway Fuel Tax Refund'), findsOneWidget);
+      expect(find.textContaining('current rate'), findsOneWidget);
+    });
+  });
 }

test/user_agreement_screen_test.dart

@@ -5,6 +5,7 @@ import 'package:provider/provider.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 
 import 'package:fuel_tax_tracker/main.dart';
+import 'package:fuel_tax_tracker/screens/faq_screen.dart';
 import 'package:fuel_tax_tracker/screens/main_shell.dart';
 import 'package:fuel_tax_tracker/screens/user_agreement_screen.dart';
 import 'package:fuel_tax_tracker/services/app_state.dart';
@@ -38,12 +39,49 @@ void main() {
   testWidgets('shows the data-loss liability section and both actions', (tester) async {
     await pumpScreen(tester);
 
+    await tester.scrollUntilVisible(
+        find.text('We Are Not Responsible for Your Data or Any Data Loss'), 300,
+        scrollable: find.byType(Scrollable));
     expect(find.text('We Are Not Responsible for Your Data or Any Data Loss'), findsOneWidget);
     expect(find.textContaining('developer is not responsible for your data'), findsOneWidget);
     expect(find.widgetWithText(FilledButton, 'I Agree'), findsOneWidget);
     expect(find.widgetWithText(OutlinedButton, 'Decline'), findsOneWidget);
   });
 
+  testWidgets('shows the privacy section disclosing no tracking and AdMob-only data collection',
+      (tester) async {
+    await pumpScreen(tester);
+
+    expect(find.text('Privacy'), findsOneWidget);
+    expect(find.textContaining("don't track or log your data"), findsOneWidget);
+    expect(find.textContaining('Google AdMob'), findsOneWidget);
+  });
+
+  testWidgets(
+      'shows both refund types and a not-tax-advice / consult-a-professional disclaimer',
+      (tester) async {
+    await pumpScreen(tester);
+
+    await tester.scrollUntilVisible(find.text('Not Tax or Legal Advice'), 300,
+        scrollable: find.byType(Scrollable));
+    expect(find.text('Not Tax or Legal Advice'), findsOneWidget);
+    expect(find.textContaining('12.5¢ per gallon for highway use'), findsOneWidget);
+    expect(find.textContaining('29.5¢ per gallon for non-highway use'), findsOneWidget);
+    expect(find.textContaining('Nothing here is tax or legal advice'), findsOneWidget);
+    expect(find.textContaining('consult a tax professional'), findsOneWidget);
+  });
+
+  testWidgets('See the FAQ for more opens FaqScreen', (tester) async {
+    await pumpScreen(tester);
+
+    await tester.scrollUntilVisible(find.text('See the FAQ for more'), 200,
+        scrollable: find.byType(Scrollable));
+    await tester.tap(find.text('See the FAQ for more'));
+    await tester.pumpAndSettle();
+
+    expect(find.byType(FaqScreen), findsOneWidget);
+  });
+
   testWidgets('I Agree marks the agreement accepted and persists it', (tester) async {
     final appState = await pumpScreen(tester);
 
@@ -78,6 +116,56 @@ void main() {
     expect(appState.hasAcceptedUserAgreement, isFalse);
   });
 
+  group('isReview mode (reached from Settings, not the first-launch gate)', () {
+    // Pushed on top of a placeholder route (rather than set as `home`
+    // directly) so there's actually something to pop back to — matching
+    // how it's really reached (pushed from Settings) and letting the
+    // automaticallyImplyLeading back button behave realistically.
+    Future<void> pumpReview(WidgetTester tester) async {
+      final appState = AppState()..isLoading = false;
+      await tester.pumpWidget(
+        ChangeNotifierProvider.value(
+          value: appState,
+          child: MaterialApp(
+            home: Builder(
+              builder: (context) => Scaffold(
+                body: Center(
+                  child: ElevatedButton(
+                    onPressed: () => Navigator.of(context).push(
+                      MaterialPageRoute(builder: (_) => const UserAgreementScreen(isReview: true)),
+                    ),
+                    child: const Text('open'),
+                  ),
+                ),
+              ),
+            ),
+          ),
+        ),
+      );
+      await tester.tap(find.text('open'));
+      await tester.pumpAndSettle();
+    }
+
+    testWidgets('hides Decline/I Agree and shows the content with a back button instead',
+        (tester) async {
+      await pumpReview(tester);
+
+      expect(find.widgetWithText(FilledButton, 'I Agree'), findsNothing);
+      expect(find.widgetWithText(OutlinedButton, 'Decline'), findsNothing);
+      expect(find.byType(BackButton), findsOneWidget);
+      expect(
+        find.text('This is the agreement you accepted when you first opened Show Me '
+            'The Fuel Refund.'),
+        findsOneWidget,
+      );
+      // Same legal content still shown, just not gating anything.
+      await tester.scrollUntilVisible(
+          find.text('We Are Not Responsible for Your Data or Any Data Loss'), 300,
+          scrollable: find.byType(Scrollable));
+      expect(find.text('We Are Not Responsible for Your Data or Any Data Loss'), findsOneWidget);
+    });
+  });
+
   group('AppRoot gating', () {
     Future<AppState> pumpRoot(WidgetTester tester, {required bool hasAcceptedUserAgreement}) async {
       final appState = AppState()

test/vehicle_detail_screen_test.dart

@@ -2,6 +2,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:provider/provider.dart';
 
+import 'package:fuel_tax_tracker/models/fuel_entry.dart';
 import 'package:fuel_tax_tracker/models/vehicle.dart';
 import 'package:fuel_tax_tracker/screens/vehicle_detail_screen.dart';
 import 'package:fuel_tax_tracker/services/app_state.dart';
@@ -85,4 +86,47 @@ void main() {
 
     expect(find.widgetWithText(AppBar, 'Truck'), findsOneWidget);
   });
+
+  testWidgets('shows an estimated fuel refund next to price/gal when the setting is on',
+      (tester) async {
+    final entry = FuelEntry(
+      id: 'e1',
+      vehicleId: 'a',
+      date: DateTime(2026, 5, 14, 9, 30),
+      gallons: 10,
+      pricePerGallon: 3.5,
+      totalCost: 35,
+      updatedAt: DateTime.utc(2026, 5, 14),
+    );
+    final appState = AppState()
+      ..isLoading = false
+      ..vehicles = [vehicleA]
+      ..fuelEntries = [entry]
+      ..showEstimatedFuelRefund = true;
+
+    await pumpDetail(tester, appState, 'a');
+
+    // 10 gal * $0.125/gal = $1.25.
+    expect(find.textContaining('\$3.50/gal  ·  Est. \$1.25'), findsOneWidget);
+  });
+
+  testWidgets('shows no estimated fuel refund when the setting is off (default)', (tester) async {
+    final entry = FuelEntry(
+      id: 'e1',
+      vehicleId: 'a',
+      date: DateTime(2026, 5, 14, 9, 30),
+      gallons: 10,
+      pricePerGallon: 3.5,
+      totalCost: 35,
+      updatedAt: DateTime.utc(2026, 5, 14),
+    );
+    final appState = AppState()
+      ..isLoading = false
+      ..vehicles = [vehicleA]
+      ..fuelEntries = [entry];
+
+    await pumpDetail(tester, appState, 'a');
+
+    expect(find.textContaining('Est. \$'), findsNothing);
+  });
 }