✅ Add tests

Author: AlexV525

pubspec.yaml

@@ -16,3 +16,7 @@ dependencies:
   photo_manager: ^2.0.7
   provider: ^6.0.1
   video_player: ^2.2.14
+
+dev_dependencies:
+  flutter_test:
+    sdk: flutter

test/delegates/builder_delegate_test.dart

@@ -0,0 +1,83 @@
+///
+/// [Author] Alex (https://github.com/AlexV525)
+/// [Date] 2022/04/27 12:14
+///
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:wechat_assets_picker/wechat_assets_picker.dart';
+
+void main() {
+  PhotoManager.withPlugin(TestPhotoManagerPlugin());
+  final Finder _defaultButtonFinder = find.byType(TextButton);
+  Widget _defaultApp({void Function(BuildContext)? onButtonPressed}) {
+    return MaterialApp(
+      home: Builder(
+        builder: (BuildContext context) => Scaffold(
+          body: Center(
+            child: TextButton(
+              onPressed: () => onButtonPressed?.call(context),
+              child: const Text('Press'),
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+
+  testWidgets('PathNameBuilder called correctly', (WidgetTester tester) async {
+    final AssetPathEntity pathEntity = AssetPathEntity(
+      id: 'test',
+      name: 'pathEntity',
+    );
+    final PathNameBuilder<AssetPathEntity> pathNameBuilder =
+        (AssetPathEntity p) => 'testPathNameBuilder';
+    final AssetPickerConfig config = AssetPickerConfig(
+      pathNameBuilder: pathNameBuilder,
+    );
+    final DefaultAssetPickerProvider provider =
+        DefaultAssetPickerProvider.forTest(
+      maxAssets: config.maxAssets,
+      pageSize: config.pageSize,
+      pathThumbnailSize: config.pathThumbnailSize,
+      selectedAssets: config.selectedAssets,
+      requestType: config.requestType,
+      sortPathDelegate: config.sortPathDelegate,
+      filterOptions: config.filterOptions,
+    );
+    provider
+      ..currentAssets = <AssetEntity>[
+        const AssetEntity(id: 'test', typeInt: 0, width: 0, height: 0),
+      ]
+      ..currentPath = pathEntity
+      ..hasAssetsToDisplay = true
+      ..setPathThumbnail(pathEntity, null);
+    final DefaultAssetPickerBuilderDelegate delegate =
+        DefaultAssetPickerBuilderDelegate(
+      provider: provider,
+      initialPermission: PermissionState.authorized,
+      pathNameBuilder: pathNameBuilder,
+    );
+    await tester.pumpWidget(
+      _defaultApp(
+        onButtonPressed: (BuildContext context) {
+          AssetPicker.pickAssetsWithDelegate(context, delegate: delegate);
+        },
+      ),
+    );
+    await tester.tap(_defaultButtonFinder);
+    await tester.pumpAndSettle();
+    await tester.tap(find.byIcon(Icons.keyboard_arrow_down));
+    await tester.pumpAndSettle();
+    expect(find.text('testPathNameBuilder'), findsNWidgets(2));
+  });
+}
+
+class TestPhotoManagerPlugin extends PhotoManagerPlugin {
+  @override
+  Future<PermissionState> requestPermissionExtend(
+    PermisstionRequestOption requestOption,
+  ) {
+    return SynchronousFuture<PermissionState>(PermissionState.authorized);
+  }
+}