feat: content downloader with sha256 verify and atomic cache

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-06-12 13:05:56 +09:00
parent c7bdb9b9c9
commit bfa9c09b28
2 changed files with 229 additions and 0 deletions
@@ -0,0 +1,132 @@
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:block_seasons/data/remote/content_downloader.dart';
+import 'package:crypto/crypto.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:http/http.dart' as http;
+import 'package:http/testing.dart';
+
+void main() {
+  late Directory tmp;
+
+  setUp(() async {
+    tmp = await Directory.systemTemp.createTemp('bs_cache_');
+  });
+
+  tearDown(() async {
+    if (await tmp.exists()) await tmp.delete(recursive: true);
+  });
+
+  String shaOf(String body) => sha256.convert(utf8.encode(body)).toString();
+
+  // Minimal pack body (repository parses later; downloader only verifies
+  // bytes).
+  const packBody = '{"schemaVersion":1,"seasonId":"season_002"}';
+
+  Map<String, dynamic> manifestJson({String? sha, int version = 1}) => {
+        'schemaVersion': 1,
+        'minAppBuild': 1,
+        'current': 'season_002',
+        'seasons': [
+          {
+            'seasonId': 'season_002',
+            'version': version,
+            'packUrl': 'seasons/season_002/pack.json',
+            'sha256': sha ?? shaOf(packBody),
+          },
+        ],
+      };
+
+  MockClient okClient({String? sha, int version = 1}) =>
+      MockClient((request) async {
+        if (request.url.path.endsWith('manifest.json')) {
+          return http.Response(
+            jsonEncode(manifestJson(sha: sha, version: version)),
+            200,
+            headers: {'content-type': 'application/json'},
+          );
+        }
+        if (request.url.path.endsWith('pack.json')) {
+          return http.Response(packBody, 200);
+        }
+        return http.Response('not found', 404);
+      });
+
+  test('downloads, verifies, and caches a new season', () async {
+    final downloader = ContentDownloader(
+      baseUrl: 'https://example.com/content',
+      cacheDir: tmp,
+      client: okClient(),
+    );
+    final updated = await downloader.sync();
+    expect(updated, isTrue);
+    final cached = File('${tmp.path}/seasons/season_002/pack.json');
+    expect(await cached.readAsString(), packBody);
+    expect(downloader.cachedVersion('season_002'), 1);
+  });
+
+  test('second sync with same version is a no-op', () async {
+    final downloader = ContentDownloader(
+      baseUrl: 'https://example.com/content',
+      cacheDir: tmp,
+      client: okClient(),
+    );
+    await downloader.sync();
+    expect(await downloader.sync(), isFalse);
+  });
+
+  test('checksum mismatch rejects the pack and keeps cache clean', () async {
+    final downloader = ContentDownloader(
+      baseUrl: 'https://example.com/content',
+      cacheDir: tmp,
+      client: okClient(sha: 'deadbeef'),
+    );
+    final updated = await downloader.sync();
+    expect(updated, isFalse);
+    expect(
+      File('${tmp.path}/seasons/season_002/pack.json').existsSync(),
+      isFalse,
+    );
+    // No stray temp files left behind.
+    final leftovers = tmp
+        .listSync(recursive: true)
+        .whereType<File>()
+        .where((f) => f.path.endsWith('.tmp'));
+    expect(leftovers, isEmpty);
+  });
+
+  test('network failure leaves existing cache untouched', () async {
+    final good = ContentDownloader(
+      baseUrl: 'https://example.com/content',
+      cacheDir: tmp,
+      client: okClient(),
+    );
+    await good.sync();
+
+    final offline = ContentDownloader(
+      baseUrl: 'https://example.com/content',
+      cacheDir: tmp,
+      client: MockClient((_) async => throw const SocketException('off')),
+    );
+    expect(await offline.sync(), isFalse);
+    expect(
+      File('${tmp.path}/seasons/season_002/pack.json').existsSync(),
+      isTrue,
+    );
+  });
+
+  test('version bump re-downloads', () async {
+    await ContentDownloader(
+      baseUrl: 'https://example.com/content',
+      cacheDir: tmp,
+      client: okClient(version: 1),
+    ).sync();
+    final updated = await ContentDownloader(
+      baseUrl: 'https://example.com/content',
+      cacheDir: tmp,
+      client: okClient(version: 2),
+    ).sync();
+    expect(updated, isTrue);
+  });
+}