A whole bunch of changes

test/fuel_report_pdf_test.dart

@@ -0,0 +1,158 @@
+import 'dart:typed_data';
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:fuel_tax_tracker/models/fuel_entry.dart';
+import 'package:fuel_tax_tracker/models/vehicle.dart';
+import 'package:fuel_tax_tracker/services/fuel_report.dart';
+import 'package:fuel_tax_tracker/services/fuel_report_pdf.dart';
+
+/// PDF content isn't practically assertable byte-for-byte, so this is a
+/// smoke test: every include-images/include-line-items combination should
+/// render without throwing and produce a well-formed (non-trivial, valid
+/// header) document — the real coverage of what each section *contains*
+/// lives in fuel_report_test.dart (data) and is exercised by hand.
+void main() {
+  final vehicle = Vehicle(
+    id: 'v1',
+    vin: '1FMPU18L1TLB51349',
+    nickname: 'Truck',
+    updatedAt: DateTime.utc(2026, 1, 1),
+  );
+
+  final entryA = FuelEntry(
+    id: 'e1',
+    vehicleId: 'v1',
+    date: DateTime(2026, 3, 5),
+    gallons: 10,
+    pricePerGallon: 3.5,
+    totalCost: 35,
+    updatedAt: DateTime.utc(2026, 3, 5),
+    receiptImagePath: '/local/a.jpg',
+  );
+  final entryB = FuelEntry(
+    id: 'e2',
+    vehicleId: 'v1',
+    date: DateTime(2026, 3, 12),
+    gallons: 12,
+    pricePerGallon: 3.6,
+    totalCost: 43.2,
+    updatedAt: DateTime.utc(2026, 3, 12),
+    receiptDriveFileId: 'remote-1',
+  );
+
+  final report = FuelReport(
+    startDate: DateTime(2026, 3, 1),
+    endDate: DateTime(2026, 3, 31),
+    rows: [
+      VehicleReportRow(
+        vehicle: vehicle,
+        entries: [entryA, entryB],
+        totalGallons: 22,
+        totalCost: 78.2,
+      ),
+    ],
+  );
+
+  // A 1x1 red pixel PNG — enough for the pdf package to embed as an image.
+  final onePixelPng = Uint8List.fromList([
+    0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A, 0x00, 0x00, 0x00, 0x0D,
+    0x49, 0x48, 0x44, 0x52, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01,
+    0x08, 0x02, 0x00, 0x00, 0x00, 0x90, 0x77, 0x53, 0xDE, 0x00, 0x00, 0x00,
+    0x0C, 0x49, 0x44, 0x41, 0x54, 0x08, 0xD7, 0x63, 0xF8, 0xCF, 0xC0, 0x00,
+    0x00, 0x03, 0x01, 0x01, 0x00, 0x18, 0xDD, 0x8D, 0xB0, 0x00, 0x00, 0x00,
+    0x00, 0x49, 0x45, 0x4E, 0x44, 0xAE, 0x42, 0x60, 0x82,
+  ]);
+
+  Future<void> expectValidPdf(Uint8List bytes) async {
+    expect(bytes.length, greaterThan(100));
+    expect(String.fromCharCodes(bytes.take(5)), '%PDF-');
+  }
+
+  test('summary only (both toggles off)', () async {
+    final bytes = await buildFuelReportPdf(report);
+    await expectValidPdf(bytes);
+  });
+
+  test('with line items, no images', () async {
+    final bytes = await buildFuelReportPdf(report, includeLineItems: true);
+    await expectValidPdf(bytes);
+  });
+
+  test('with images, no line items', () async {
+    final bytes = await buildFuelReportPdf(
+      report,
+      includeReceiptImages: true,
+      receiptImages: {'e1': onePixelPng, 'e2': onePixelPng},
+    );
+    await expectValidPdf(bytes);
+  });
+
+  test('with both — line items and images each get their own section, cross-referenced by number',
+      () async {
+    final bytes = await buildFuelReportPdf(
+      report,
+      includeLineItems: true,
+      includeReceiptImages: true,
+      receiptImages: {'e1': onePixelPng, 'e2': onePixelPng},
+    );
+    await expectValidPdf(bytes);
+  });
+
+  test('a report with enough entries to span multiple pages does not throw', () async {
+    // Regression test: the page banner/watermark used to be drawn by
+    // wrapping the *entire*, unbounded-height body in a Stack, which
+    // doesn't paginate — MultiPage threw "Widget won't fit into the page"
+    // for anything long enough to need a page break. Enough months/entries
+    // here to force at least one break.
+    final vehicle2 = Vehicle(id: 'v2', vin: '1GNWK5EG4DR302326', updatedAt: DateTime.utc(2026, 1, 1));
+    final manyEntries = <FuelEntry>[];
+    for (var month = 1; month <= 12; month++) {
+      for (var day = 2; day <= 26; day += 6) {
+        final id = 'm$month-d$day';
+        manyEntries.add(FuelEntry(
+          id: id,
+          vehicleId: month.isEven ? 'v1' : 'v2',
+          date: DateTime(2026, month, day),
+          gallons: 20,
+          pricePerGallon: 3.5,
+          totalCost: 70,
+          updatedAt: DateTime.utc(2026, month, day),
+          receiptDriveFileId: 'remote-$id',
+        ));
+      }
+    }
+    final bigReport = buildFuelReport(
+      vehicles: [vehicle, vehicle2],
+      fuelEntries: manyEntries,
+      startDate: DateTime(2026, 1, 1),
+      endDate: DateTime(2026, 12, 31),
+    );
+
+    final bytes = await buildFuelReportPdf(
+      bigReport,
+      includeLineItems: true,
+      includeReceiptImages: true,
+      receiptImages: {for (final e in manyEntries) e.id: onePixelPng},
+    );
+    await expectValidPdf(bytes);
+  });
+
+  test('receiptImages missing an entry does not crash — that photo is just skipped', () async {
+    final bytes = await buildFuelReportPdf(
+      report,
+      includeReceiptImages: true,
+      receiptImages: {'e1': onePixelPng}, // e2 deliberately missing
+    );
+    await expectValidPdf(bytes);
+  });
+
+  test('empty report (no rows) with all sections on', () async {
+    final empty = FuelReport(startDate: DateTime(2026, 1, 1), endDate: DateTime(2026, 1, 31), rows: []);
+    final bytes = await buildFuelReportPdf(empty, includeLineItems: true, includeReceiptImages: true);
+    await expectValidPdf(bytes);
+  });
+
+  test('fuelReportFileName formats the date range', () {
+    expect(fuelReportFileName(report), 'fuel-report-20260301-20260331.pdf');
+  });
+}