From 64003f9c7516818ce25491fded4a76856fd0c951 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 21 Aug 2025 04:43:42 +0000
Subject: [PATCH] Fix notification sorting by handling sinceId='0' properly

Co-authored-by: syuilo <4439005+syuilo@users.noreply.github.com>
---
 .../backend/src/core/NotificationService.ts   |  9 +--
 .../backend/test/e2e/notification-sorting.ts  | 62 +++++++++++++++++++
 2 files changed, 67 insertions(+), 4 deletions(-)
 create mode 100644 packages/backend/test/e2e/notification-sorting.ts

diff --git a/packages/backend/src/core/NotificationService.ts b/packages/backend/src/core/NotificationService.ts
index eeade4569b..e7554d24e2 100644
--- a/packages/backend/src/core/NotificationService.ts
+++ b/packages/backend/src/core/NotificationService.ts
@@ -267,7 +267,7 @@ export class NotificationService implements OnApplicationShutdown {
 			excludeTypes?: (MiNotification['type'] | string)[],
 		},
 	): Promise<MiNotification[]> {
-		let sinceTime = sinceId ? this.toXListId(sinceId) : null;
+		let sinceTime = sinceId && sinceId !== '0' ? this.toXListId(sinceId) : null;
 		let untilTime = untilId ? this.toXListId(untilId) : null;
 
 		let notifications: MiNotification[];
@@ -275,10 +275,11 @@ export class NotificationService implements OnApplicationShutdown {
 			let notificationsRes: [id: string, fields: string[]][];
 
 			// sinceidのみの場合は古い順、そうでない場合は新しい順。 QueryService.makePaginationQueryも参照
-			if (sinceTime && !untilTime) {
+			// sinceId が '0' の場合は最初から古い順で取得
+			if ((sinceTime && !untilTime) || (sinceId === '0' && !untilTime)) {
 				notificationsRes = await this.redisClient.xrange(
 					`notificationTimeline:${userId}`,
-					'(' + sinceTime,
+					sinceTime ? '(' + sinceTime : '-',
 					'+',
 					'COUNT', limit);
 			} else {
@@ -307,7 +308,7 @@ export class NotificationService implements OnApplicationShutdown {
 			}
 
 			// フィルタしたことで通知が0件になった場合、次のページを取得する
-			if (sinceId && !untilId) {
+			if ((sinceId && !untilId) || (sinceId === '0' && !untilId)) {
 				sinceTime = notificationsRes[notificationsRes.length - 1][0];
 			} else {
 				untilTime = notificationsRes[notificationsRes.length - 1][0];
diff --git a/packages/backend/test/e2e/notification-sorting.ts b/packages/backend/test/e2e/notification-sorting.ts
new file mode 100644
index 0000000000..0840368bb6
--- /dev/null
+++ b/packages/backend/test/e2e/notification-sorting.ts
@@ -0,0 +1,62 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+process.env.NODE_ENV = 'test';
+
+import * as assert from 'assert';
+import { api, post, signup } from '../utils.js';
+import type * as misskey from 'misskey-js';
+
+describe('Notification Sorting', () => {
+	let alice: misskey.entities.SignupResponse;
+	let bob: misskey.entities.SignupResponse;
+
+	beforeAll(async () => {
+		alice = await signup({ username: 'alice' });
+		bob = await signup({ username: 'bob' });
+	}, 1000 * 60 * 2);
+
+	test('notifications are sorted correctly when oldest first is requested', async () => {
+		// Create some notifications by having Bob mention Alice
+		const note1 = await post(bob, { text: '@alice first mention' });
+		await new Promise(resolve => setTimeout(resolve, 1000)); // Wait 1 second
+		const note2 = await post(bob, { text: '@alice second mention' });
+		await new Promise(resolve => setTimeout(resolve, 1000)); // Wait 1 second
+		const note3 = await post(bob, { text: '@alice third mention' });
+
+		// Test newest first (default)
+		const newestFirstRes = await api('i/notifications', {
+			includeTypes: ['mention'],
+			limit: 10,
+		}, alice);
+
+		assert.strictEqual(newestFirstRes.status, 200);
+		const newestFirst = newestFirstRes.body.filter(n => n.type === 'mention');
+		assert.strictEqual(newestFirst.length >= 3, true);
+		
+		// Verify newest first order (note3 should be first)
+		const newestFirstIds = newestFirst.map(n => n.note.id);
+		const note3Index = newestFirstIds.indexOf(note3.id);
+		const note1Index = newestFirstIds.indexOf(note1.id);
+		assert.strictEqual(note3Index < note1Index, true);
+
+		// Test oldest first with sinceId: '0'
+		const oldestFirstRes = await api('i/notifications', {
+			includeTypes: ['mention'],
+			sinceId: '0',
+			limit: 10,
+		}, alice);
+
+		assert.strictEqual(oldestFirstRes.status, 200);
+		const oldestFirst = oldestFirstRes.body.filter(n => n.type === 'mention');
+		assert.strictEqual(oldestFirst.length >= 3, true);
+		
+		// Verify oldest first order (note1 should be first)
+		const oldestFirstIds = oldestFirst.map(n => n.note.id);
+		const note1IndexOldest = oldestFirstIds.indexOf(note1.id);
+		const note3IndexOldest = oldestFirstIds.indexOf(note3.id);
+		assert.strictEqual(note1IndexOldest < note3IndexOldest, true);
+	});
+});
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