A whole bunch of changes

test/image_source_sheet_test.dart

@@ -0,0 +1,68 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:fuel_tax_tracker/widgets/image_source_sheet.dart';
+
+/// Covers the optional [heading] and [onInfoTap] on [chooseImageSource]'s
+/// bottom sheet — receipt capture passes "Receipt From" with no info
+/// button (see receipt_capture.dart); VIN scanning passes "VIN From" plus
+/// an info button that explains where to find one (see
+/// add_edit_vehicle_screen.dart).
+void main() {
+  Future<void> pumpSheet(
+    WidgetTester tester, {
+    String? heading,
+    VoidCallback? onInfoTap,
+  }) async {
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Builder(
+          builder: (context) => ElevatedButton(
+            onPressed: () => chooseImageSource(context, heading: heading, onInfoTap: onInfoTap),
+            child: const Text('Open'),
+          ),
+        ),
+      ),
+    );
+    await tester.tap(find.text('Open'));
+    await tester.pumpAndSettle();
+  }
+
+  testWidgets('shows the heading above Take Photo / Choose from Gallery when provided',
+      (tester) async {
+    await pumpSheet(tester, heading: 'Receipt From');
+
+    expect(find.text('Receipt From'), findsOneWidget);
+    expect(find.text('Take Photo'), findsOneWidget);
+    expect(find.text('Choose from Gallery'), findsOneWidget);
+  });
+
+  testWidgets('shows no heading when none is provided', (tester) async {
+    await pumpSheet(tester);
+
+    expect(find.text('Receipt From'), findsNothing);
+    expect(find.text('Take Photo'), findsOneWidget);
+    expect(find.text('Choose from Gallery'), findsOneWidget);
+  });
+
+  testWidgets('shows no info button when onInfoTap is omitted, even with a heading',
+      (tester) async {
+    await pumpSheet(tester, heading: 'Receipt From');
+
+    expect(find.byIcon(Icons.info_outline), findsNothing);
+  });
+
+  testWidgets('shows an info button next to the heading when onInfoTap is provided, and invokes it',
+      (tester) async {
+    var tapped = false;
+    await pumpSheet(tester, heading: 'VIN From', onInfoTap: () => tapped = true);
+
+    expect(find.text('VIN From'), findsOneWidget);
+    expect(find.byIcon(Icons.info_outline), findsOneWidget);
+
+    await tester.tap(find.byIcon(Icons.info_outline));
+    await tester.pumpAndSettle();
+
+    expect(tapped, isTrue);
+  });
+}