test: add tests for TbdexQuoteNotifier

test/features/tbdex/tbdex_quote_notifier_test.dart

@@ -0,0 +1,68 @@
+import 'package:didpay/features/did/did_provider.dart';
+import 'package:didpay/features/tbdex/tbdex_quote_notifier.dart';
+import 'package:didpay/features/tbdex/tbdex_service.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:mocktail/mocktail.dart';
+
+import '../../helpers/mocks.dart';
+import '../../helpers/riverpod_helpers.dart';
+import '../../helpers/test_data.dart';
+
+Future<void> main() async {
+  await TestData.initializeDids();
+
+  final did = TestData.aliceDid;
+  const pfiDid = '123';
+  const exchangeId = 'rfq_01ha835rhefwmagsknrrhvaa0k';
+
+  group('TbdexQuoteNotifier`', () {
+    group('startPolling', () {
+      test('should return Quote if successful', () async {
+        final mockTbdexService = MockTbdexService();
+        final quote = TestData.getQuote();
+
+        when(() => mockTbdexService.getExchange(did, pfiDid, exchangeId))
+            .thenAnswer((_) async => [quote]);
+
+        final container = createContainer(
+          overrides: [
+            tbdexServiceProvider.overrideWith(
+              (ref) => mockTbdexService,
+            ),
+            didProvider.overrideWith((ref) => did),
+          ],
+        );
+
+        final tbdexQuoteNotifier = container.read(quoteProvider.notifier);
+
+        final result =
+            await tbdexQuoteNotifier.startPolling(pfiDid, exchangeId);
+
+        expect(result, quote);
+      });
+
+      test('should throw an Exception if not successful', () async {
+        final mockTbdexService = MockTbdexService();
+
+        when(() => mockTbdexService.getExchange(did, pfiDid, exchangeId))
+            .thenThrow(Exception('Error'));
+
+        final container = createContainer(
+          overrides: [
+            tbdexServiceProvider.overrideWith(
+              (ref) => mockTbdexService,
+            ),
+            didProvider.overrideWith((ref) => did),
+          ],
+        );
+
+        final tbdexQuoteNotifier = container.read(quoteProvider.notifier);
+
+        expect(
+          () => tbdexQuoteNotifier.startPolling(pfiDid, exchangeId),
+          throwsA(isA<Exception>()),
+        );
+      });
+    });
+  });
+}