fix(library): bound playlist picker SQL parameters

Deduplicate requested track keys and aggregate match counts in batches of 500 parameters. Use scalar preview lookups instead of expanding another playlist ID list. Cover large selections, duplicate keys, empty selections, and cover selection in regression tests.
2026-09-17 15:22:34 +02:00 · 2026-09-06 14:04:05 +07:00
parent 3d35058b02
commit 7c12f548d7
2 changed files with 208 additions and 110 deletions
@@ -0,0 +1,118 @@
+import 'dart:convert';
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:sqflite/sqflite.dart';
+import 'package:spotiflac_android/services/library_collections_database.dart';
+
+// Exercises the database boundary's bounded requests and aggregation without
+// requiring a platform SQLite plugin. The production SQL is passed unchanged.
+class _PickerDatabase implements DatabaseExecutor {
+  final List<Map<String, Object?>> playlistRows;
+  final Map<String, Set<String>> membership;
+  final batches = <List<Object?>>[];
+  int summaryQueries = 0;
+
+  _PickerDatabase(this.playlistRows, this.membership);
+
+  @override
+  Future<List<Map<String, Object?>>> rawQuery(
+    String sql, [
+    List<Object?>? arguments,
+  ]) async {
+    if (arguments == null) {
+      summaryQueries++;
+      expect(sql, contains('preview_track_json'));
+      return playlistRows;
+    }
+    // Emulate a database with a conservative parameter budget. Regressing to
+    // one unbounded query must fail even on hosts with a larger SQLite limit.
+    if (arguments.length > 500) throw StateError('too many SQL variables');
+    expect('?'.allMatches(sql).length, arguments.length);
+    batches.add(List.of(arguments));
+    return [
+      for (final entry in membership.entries)
+        {
+          'playlist_id': entry.key,
+          'matched_count': arguments.where(entry.value.contains).length,
+        },
+    ];
+  }
+
+  @override
+  dynamic noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}
+
+Map<String, Object?> _playlist(String id, {String? cover, String? preview}) => {
+  'id': id,
+  'name': id,
+  'cover_image_path': cover,
+  'preview_track_json': preview,
+  'created_at': '2026-01-01T00:00:00Z',
+  'updated_at': '2026-01-02T00:00:00Z',
+  'track_count': 1205,
+};
+
+void main() {
+  test(
+    'large selections aggregate across batches and deduplicate keys',
+    () async {
+      final keys = List.generate(1205, (i) => 'track-$i');
+      final db = _PickerDatabase(
+        [
+          _playlist('partial'),
+          _playlist(
+            'full',
+            preview: jsonEncode({'coverUrl': 'https://example.test/cover'}),
+          ),
+          _playlist('empty'),
+        ],
+        {'full': keys.toSet(), 'partial': keys.take(1204).toSet(), 'empty': {}},
+      );
+      final rows = await readPlaylistPickerSummaries(db, [
+        ...keys,
+        ...keys.take(10),
+        '',
+        ' ',
+      ]);
+      expect(db.batches.map((batch) => batch.length), [500, 500, 205]);
+      expect(db.batches.expand((batch) => batch).toList(), keys);
+      expect(db.summaryQueries, 1);
+      expect(rows.map((row) => row.id), ['partial', 'full', 'empty']);
+      expect(rows.map((row) => row.containsAllRequestedTracks), [
+        false,
+        true,
+        false,
+      ]);
+      expect(rows[1].previewCover, 'https://example.test/cover');
+      expect(rows[1].trackCount, 1205);
+    },
+  );
+
+  test(
+    'empty selection performs no matching query or implicit all-match',
+    () async {
+      final db = _PickerDatabase([_playlist('playlist')], {});
+      final rows = await readPlaylistPickerSummaries(db, ['', ' ']);
+      expect(db.batches, isEmpty);
+      expect(rows.single.containsAllRequestedTracks, isFalse);
+    },
+  );
+
+  test(
+    'many playlist previews need no parameter list and tolerate bad JSON',
+    () async {
+      final db = _PickerDatabase([
+        for (var i = 0; i < 1200; i++) _playlist('$i'),
+        _playlist('custom', cover: '/local/cover.jpg'),
+        _playlist('bad', preview: '{broken'),
+        _playlist('blank', preview: '{"coverUrl":""}'),
+      ], {});
+      final rows = await readPlaylistPickerSummaries(db, []);
+      expect(rows, hasLength(1203));
+      expect(db.summaryQueries, 1);
+      expect(db.batches, isEmpty);
+      expect(rows[1200].coverImagePath, '/local/cover.jpg');
+      expect(rows.map((row) => row.previewCover), everyElement(isNull));
+    },
+  );
+}