fix(threads): announce threads above the latest five messages (#3307)

fluxer_api/src/api/channel/services/thread/ThreadCreationService.ts

@@ -76,10 +76,9 @@ import type {
 } from '@fluxer/schema/src/domains/channel/ForumRequestSchemas';
 import type {ThreadChannelResponse} from '@fluxer/schema/src/domains/channel/ThreadRequestSchemas';
 import type {MessageResponse} from '@fluxer/schema/src/domains/message/MessageResponseSchemas';
-import {snowflakeToDate} from '@fluxer/snowflake/src/Snowflake';
 import * as BucketUtils from '@fluxer/snowflake/src/SnowflakeBuckets';
 
-const THREAD_CREATED_MESSAGE_MIN_SOURCE_AGE_MS = 5 * 60 * 1000;
+const THREAD_CREATED_MESSAGE_RECENT_WINDOW = 5;
 
 function slowmodeThreadKey(parentId: ChannelID, userId: UserID): string {
 	return `slowmode-thread:${parentId}:${userId}`;
@@ -159,13 +158,22 @@ export class ThreadCreationService {
 		}
 		const starter = await this.buildStarterEvent(params.viewer, params.user.id, view, params.requestCache);
 		if (starter) events.push(starter);
-		if (Date.now() - snowflakeToDate(source.id).getTime() >= THREAD_CREATED_MESSAGE_MIN_SOURCE_AGE_MS) {
+		if (!(await this.isAmongRecentMessages(parentAuth.channel.id, source.id))) {
 			events.push(await this.createThreadCreatedMessage(parentAuth.channel, view, params.user.id));
 		}
 		await dispatchThreadEvents(this.ctx.gatewayService, view.state.guildId, events);
 		return mapThreadToResponse(view);
 	}
 
+	private async isAmongRecentMessages(channelId: ChannelID, messageId: MessageID): Promise<boolean> {
+		const recent = await this.ctx.channelRepository.messages.listMessages(
+			channelId,
+			undefined,
+			THREAD_CREATED_MESSAGE_RECENT_WINDOW,
+		);
+		return recent.some((message) => message.id === messageId);
+	}
+
 	async authenticateParent(viewer: ThreadViewer, userId: UserID, channelId: ChannelID): Promise<AuthenticatedChannel> {
 		return this.ctx.channelAuth.getChannelAuthenticated({userId, channelId, viewer});
 	}

fluxer_api/src/api/channel/tests/ThreadRoutes.test.ts

@@ -268,25 +268,28 @@ describe('thread routes', () => {
 			expect(member?.flags).toBe(ThreadMemberFlags.HAS_INTERACTED);
 		});
 
-		it('announces threads started from older messages in the parent without moving its last message', async () => {
+		it('announces threads started from messages above the latest five without moving its last message', async () => {
 			const s = await setup();
-			const message = await sendMessage(harness, s.owner.token, s.channelId, 'old news');
+			const pushedUp = await sendMessage(harness, s.owner.token, s.channelId, 'old news');
-			const now = Date.now();
+			const nearBottom = await sendMessage(harness, s.owner.token, s.channelId, 'recent news');
-			vi.spyOn(Date, 'now').mockReturnValue(now + 6 * 60 * 1000);
+			let latest = nearBottom;
+			for (let i = 0; i < 4; i++) latest = await sendMessage(harness, s.owner.token, s.channelId, `filler ${i}`);
 			const dispatch = vi.spyOn(NoopGatewayService.prototype, 'dispatchGuild');
+			for (const message of [nearBottom, pushedUp]) {
 				await threadsRequest(harness, s.owner.token)
 					.post(`/channels/${s.channelId}/messages/${message.id}/threads`)
-				.body({name: 'Later'})
+					.body({name: message.content})
 					.expect(201)
 					.execute();
+			}
 			const announced = dispatch.mock.calls
 				.map(([params]) => params.data as MessageResponse)
 				.filter((data) => data.type === MessageTypes.THREAD_CREATED);
 			expect(announced).toHaveLength(1);
-			expect(announced[0]).toMatchObject({channel_id: s.channelId, content: 'Later'});
+			expect(announced[0]).toMatchObject({channel_id: s.channelId, content: 'old news'});
-			expect(announced[0]!.message_reference?.channel_id).toBe(message.id);
+			expect(announced[0]!.message_reference?.channel_id).toBe(pushedUp.id);
 			const parent = await repository.findUnique(createChannelID(BigInt(s.channelId)));
-			expect(parent?.lastMessageId?.toString()).toBe(message.id);
+			expect(parent?.lastMessageId?.toString()).toBe(latest.id);
 		});
 
 		it('refuses a second thread on the same message', async () => {