Test: Unit Tests for Extension Registry (EXT-4)

lib/core/extensions/extension_paths.dart

@@ -1,15 +1,22 @@
 import 'dart:io';
 
+import 'package:flutter/foundation.dart';
 import 'package:path/path.dart' as p;
 import 'package:path_provider/path_provider.dart';
 
 /// Centralizes extension file locations.
 abstract final class ExtensionPaths {
   static const _extensionsSegment = 'extensions';
 
+  @visibleForTesting
+  static Directory? mockExtensionsDirectory;
+
   /// Returns `~/.querya/extensions` on Linux/Mac, or equivalent `USERPROFILE\.querya\extensions` on Windows.
   /// Falls back to application support directory if HOME is unavailable.
   static Future<Directory> extensionsDirectory() async {
+    if (mockExtensionsDirectory != null) {
+      return mockExtensionsDirectory!;
+    }
     final home = Platform.environment['HOME'] ?? Platform.environment['USERPROFILE'];
     if (home == null || home.isEmpty) {
       final support = await getApplicationSupportDirectory();

test/core/extensions/local_extension_registry_test.dart

@@ -0,0 +1,96 @@
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:path/path.dart' as p;
+import 'package:querya_desktop/core/extensions/extension_paths.dart';
+import 'package:querya_desktop/core/extensions/local_extension_registry.dart';
+import 'package:querya_desktop/core/extensions/models/extension_type.dart';
+
+void main() {
+  group('LocalExtensionRegistry', () {
+    late Directory tempDir;
+
+    setUp(() async {
+      tempDir = await Directory.systemTemp.createTemp('querya_extensions_test');
+      ExtensionPaths.mockExtensionsDirectory = tempDir;
+    });
+
+    tearDown(() async {
+      ExtensionPaths.mockExtensionsDirectory = null;
+      if (await tempDir.exists()) {
+        await tempDir.delete(recursive: true);
+      }
+    });
+
+    test('loads extensions from manifest files', () async {
+      // Create a valid extension folder
+      final ext1Dir = Directory(p.join(tempDir.path, 'ext1'));
+      await ext1Dir.create();
+
+      final manifest1 = {
+        'id': 'test.ext1',
+        'name': 'Test Extension 1',
+        'version': '1.0.0',
+        'publisher': 'Test',
+        'type': 'theme',
+        'engines': {'querya_desktop': '^1.0.0'},
+      };
+
+      final file1 = File(p.join(ext1Dir.path, 'manifest.json'));
+      await file1.writeAsString(jsonEncode(manifest1));
+
+      // Create an invalid extension folder (no manifest)
+      final ext2Dir = Directory(p.join(tempDir.path, 'ext2'));
+      await ext2Dir.create();
+
+      // Create a file that is not a directory
+      final notADir = File(p.join(tempDir.path, 'not_a_dir.txt'));
+      await notADir.writeAsString('I am a file');
+
+      // Reload registry to scan the test directory
+      await LocalExtensionRegistry.instance.reload();
+      final manifests = LocalExtensionRegistry.instance.manifests;
+
+      expect(manifests.length, 1);
+      final loaded = manifests.first;
+      expect(loaded.id, 'test.ext1');
+      expect(loaded.type, ExtensionType.theme);
+      expect(loaded.installPath, ext1Dir.path);
+    });
+
+    test('ignores directories with invalid manifest.json', () async {
+      final extDir = Directory(p.join(tempDir.path, 'bad_ext'));
+      await extDir.create();
+
+      final file = File(p.join(extDir.path, 'manifest.json'));
+      await file.writeAsString('{"invalid_json": '); // Syntax error
+
+      await LocalExtensionRegistry.instance.reload();
+
+      expect(LocalExtensionRegistry.instance.manifests, isEmpty);
+    });
+
+    test('returns cached manifests on subsequent load calls', () async {
+      final extDir = Directory(p.join(tempDir.path, 'ext3'));
+      await extDir.create();
+      final file = File(p.join(extDir.path, 'manifest.json'));
+      await file.writeAsString(jsonEncode({
+        'id': 'test.ext3',
+        'name': 'Test Ext 3',
+        'version': '1.0.0',
+        'publisher': 'Test',
+        'type': 'theme',
+        'engines': {}
+      }));
+
+      await LocalExtensionRegistry.instance.reload();
+      expect(LocalExtensionRegistry.instance.manifests.length, 1);
+
+      // Delete the file. load() shouldn't read from disk again unless reload() is called
+      await file.delete();
+      final manifests = await LocalExtensionRegistry.instance.load();
+      expect(manifests.length, 1, reason: 'Should return cached result');
+    });
+  });
+}