chore: Add tests and mock for testing the AssetManager implementation

The build.yaml was added to be able to create the AssetManager mock. See more here: https://stackoverflow.com/a/68275812

packages/package_info_plus/package_info_plus/example/build.yaml

@@ -0,0 +1,13 @@
+targets:
+  $default:
+    sources:
+      - $package$
+      - lib/$lib$
+      - lib/**.dart
+      - test/**.dart
+      - integration_test/**.dart
+    builders:
+      mockito|mockBuilder:
+        generate_for:
+          - test/**.dart
+          - integration_test/**.dart

packages/package_info_plus/package_info_plus/example/integration_test/package_info_plus_web_test.dart

@@ -2,6 +2,7 @@
 library package_info_plus_web_test;
 
 import 'dart:convert';
+import 'dart:ui_web' as ui_web;
 
 import 'package:clock/clock.dart';
 import 'package:flutter_test/flutter_test.dart';
@@ -14,7 +15,7 @@ import 'package:package_info_plus/src/package_info_plus_web.dart';
 import 'package_info_plus_test.dart' as common_tests;
 import 'package_info_plus_web_test.mocks.dart';
 
-@GenerateMocks([http.Client])
+@GenerateMocks([http.Client, ui_web.AssetManager])
 void main() {
   common_tests.main();
 
@@ -30,17 +31,28 @@ void main() {
     'build_signature': '',
   };
 
+  // ignore: constant_identifier_names
+  const VERSION_2_JSON = {
+    'app_name': 'package_info_example',
+    'build_number': '2',
+    'package_name': 'io.flutter.plugins.packageinfoexample',
+    'version': '2.0',
+    'installerStore': null,
+    'build_signature': '',
+  };
+
   late PackageInfoPlusWebPlugin plugin;
   late MockClient client;
-
-  setUp(() {
-    client = MockClient();
-    plugin = PackageInfoPlusWebPlugin(client);
-  });
+  late MockAssetManager assetManagerMock;
 
   group(
     'Package Info Web',
     () {
+      setUp(() {
+        client = MockClient();
+        plugin = PackageInfoPlusWebPlugin(client);
+      });
+
       testWidgets(
         'Get correct values when response status is 200',
         (tester) async {
@@ -207,4 +219,89 @@ void main() {
       });
     },
   );
+
+  group('Package Info Web (using MockAssetManager)', () {
+    setUp(() {
+      client = MockClient();
+      assetManagerMock = MockAssetManager();
+      plugin = PackageInfoPlusWebPlugin(client, assetManagerMock);
+    });
+
+    testWidgets(
+      'Get correct values when using the AssetManager baseUrl',
+      (tester) async {
+        const String baseUrl = 'https://an.example.com/using-asset-manager/';
+        const String assetsDir = 'assets';
+        final DateTime now = DateTime.now();
+        final Clock fakeClock = Clock(() => now);
+
+        when(assetManagerMock.assetsDir).thenReturn(assetsDir);
+        when(assetManagerMock.getAssetUrl(''))
+            .thenReturn('$baseUrl$assetsDir/');
+
+        await withClock(fakeClock, () async {
+          final int cache = now.millisecondsSinceEpoch;
+
+          when(client.get(
+            Uri.parse('${baseUrl}version.json?cachebuster=$cache'),
+          )).thenAnswer(
+            (_) => Future.value(
+              http.Response(jsonEncode(VERSION_JSON), 200),
+            ),
+          );
+
+          final versionMap = await plugin.getAll();
+
+          expect(versionMap.appName, VERSION_JSON['app_name']);
+          expect(versionMap.version, VERSION_JSON['version']);
+          expect(versionMap.buildNumber, VERSION_JSON['build_number']);
+          expect(versionMap.packageName, VERSION_JSON['package_name']);
+          expect(versionMap.buildSignature, VERSION_JSON['build_signature']);
+        });
+      },
+    );
+
+    testWidgets(
+      'Has preference for the custom base URL over the other 2 locations',
+      (tester) async {
+        const String customBaseUrl = 'https://www.example.com/with-path/';
+        const String managerBaseUrl = 'https://www.asset-manager.com/path/';
+        const String assetsDir = 'assets';
+        final DateTime now = DateTime.now();
+        final Clock fakeClock = Clock(() => now);
+
+        when(assetManagerMock.assetsDir).thenReturn(assetsDir);
+        when(assetManagerMock.getAssetUrl(''))
+            .thenReturn('$managerBaseUrl$assetsDir/');
+
+        await withClock(fakeClock, () async {
+          final int cache = now.millisecondsSinceEpoch;
+
+          when(client.get(
+            Uri.parse('${customBaseUrl}version.json?cachebuster=$cache'),
+          )).thenAnswer(
+            (_) => Future.value(
+              http.Response(jsonEncode(VERSION_JSON), 200),
+            ),
+          );
+
+          when(client.get(
+            Uri.parse('${managerBaseUrl}version.json?cachebuster=$cache'),
+          )).thenAnswer(
+            (_) => Future.value(
+              http.Response(jsonEncode(VERSION_2_JSON), 200),
+            ),
+          );
+
+          final versionMap = await plugin.getAll(baseUrl: customBaseUrl);
+
+          expect(versionMap.appName, VERSION_JSON['app_name']);
+          expect(versionMap.version, VERSION_JSON['version']);
+          expect(versionMap.buildNumber, VERSION_JSON['build_number']);
+          expect(versionMap.packageName, VERSION_JSON['package_name']);
+          expect(versionMap.buildSignature, VERSION_JSON['build_signature']);
+        });
+      },
+    );
+  });
 }