fix(app): pick default channel when guild channels arrive late (#2475)

fluxer_app/src/app/router/components/GuildChannelRouter.tsx

@@ -3,7 +3,7 @@
 import {Routes} from '@app/app/Routes';
 import {GuildLayout} from '@app/features/app/components/layout/GuildLayout';
 import Channels from '@app/features/channel/state/Channels';
-import {compareChannelPosition, filterViewableChannels} from '@app/features/messaging/utils/ChannelShared';
+import {pickDefaultGuildChannelId} from '@app/features/messaging/utils/ChannelShared';
 import * as NavigationCommands from '@app/features/navigation/commands/NavigationCommands';
 import SelectedChannel from '@app/features/navigation/state/SelectedChannel';
 import {useLocation} from '@app/features/platform/components/router/RouterReact';
@@ -13,47 +13,33 @@ import {observer} from 'mobx-react-lite';
 import type React from 'react';
 import {useEffect} from 'react';
 
+function isGuildRootPath(pathname: string, guildId: string): boolean {
+	if (guildId === ME || pathname === Routes.ME || pathname.startsWith(Routes.ME)) {
+		return false;
+	}
+	if (!pathname.startsWith('/channels/')) {
+		return false;
+	}
+	const segments = pathname.split('/');
+	return segments.length === 3 && segments[2] === guildId;
+}
+
 export const GuildChannelRouter = observer<{guildId: string; children: React.ReactNode}>(({guildId, children}) => {
 	const location = useLocation();
+	const needsDefaultChannel = !MobileLayout.enabled && isGuildRootPath(location.pathname, guildId);
+	const defaultChannelId = needsDefaultChannel
+		? pickDefaultGuildChannelId({
+				guildId,
+				channels: Channels.getGuildChannels(guildId),
+				selectedChannelId: SelectedChannel.selectedChannelIds.get(guildId),
+			})
+		: null;
 	useEffect(() => {
-		if (guildId === ME || location.pathname === Routes.ME) {
+		if (!defaultChannelId) {
 			return;
 		}
-		if (MobileLayout.enabled) {
-			return;
-		}
-		if (location.pathname.startsWith('/channels/') && !location.pathname.startsWith(Routes.ME)) {
-			if (location.pathname.split('/').length === 3) {
-				const pathSegments = location.pathname.split('/');
-				const currentGuildId = pathSegments[2];
-				if (currentGuildId !== guildId) {
-					return;
-				}
-				const selectedChannelId = SelectedChannel.selectedChannelIds.get(guildId);
-				if (selectedChannelId) {
-					const channel = Channels.getChannel(selectedChannelId);
-					const isViewableChannel = channel ? filterViewableChannels([channel]).length > 0 : false;
-					if (channel && channel.guildId === guildId && isViewableChannel) {
-						NavigationCommands.selectChannel(guildId, selectedChannelId, undefined, 'replace');
-					} else {
-						const channels = Channels.getGuildChannels(guildId);
-						const viewableChannels = filterViewableChannels(channels).sort(compareChannelPosition);
-						if (viewableChannels.length > 0) {
-							const firstChannel = viewableChannels[0];
-							NavigationCommands.selectChannel(guildId, firstChannel.id, undefined, 'replace');
-						}
-					}
-				} else {
-					const channels = Channels.getGuildChannels(guildId);
-					const viewableChannels = filterViewableChannels(channels).sort(compareChannelPosition);
-					if (viewableChannels.length > 0) {
-						const firstChannel = viewableChannels[0];
-						NavigationCommands.selectChannel(guildId, firstChannel.id, undefined, 'replace');
-					}
-				}
-			}
-		}
-	}, [guildId, location.pathname, MobileLayout.enabled]);
+		NavigationCommands.selectChannel(guildId, defaultChannelId, undefined, 'replace');
+	}, [guildId, defaultChannelId]);
 	if (guildId === ME || location.pathname === Routes.ME) {
 		return null;
 	}

fluxer_app/src/features/messaging/utils/ChannelShared.test.ts

@@ -2,7 +2,7 @@
 
 import {ChannelTypes} from '@fluxer/constants/src/ChannelConstants';
 import {describe, expect, it} from 'vitest';
-import {filterViewableChannels} from './ChannelShared';
+import {filterViewableChannels, pickDefaultGuildChannelId} from './ChannelShared';
 
 describe('filterViewableChannels', () => {
 	it('excludes link channels from default navigation fallbacks', () => {
@@ -15,3 +15,41 @@ describe('filterViewableChannels', () => {
 		expect(filterViewableChannels(channels).map((channel) => channel.id)).toEqual(['text', 'voice']);
 	});
 });
+
+describe('pickDefaultGuildChannelId', () => {
+	const channels = [
+		{id: 'category', type: ChannelTypes.GUILD_CATEGORY, position: 1, guildId: 'guild'},
+		{id: 'link', type: ChannelTypes.GUILD_LINK, position: 2, guildId: 'guild'},
+		{id: 'rules', type: ChannelTypes.GUILD_TEXT, position: 3, guildId: 'guild'},
+		{id: 'general', type: ChannelTypes.GUILD_TEXT, position: 4, guildId: 'guild'},
+		{id: 'voice', type: ChannelTypes.GUILD_VOICE, position: 5, guildId: 'guild'},
+	];
+
+	it('returns null while the guild has no channels yet', () => {
+		expect(pickDefaultGuildChannelId({guildId: 'guild', channels: []})).toBeNull();
+	});
+
+	it('picks the first channel by position, skipping categories and links', () => {
+		expect(pickDefaultGuildChannelId({guildId: 'guild', channels})).toBe('rules');
+	});
+
+	it('keeps the remembered channel for the guild', () => {
+		expect(pickDefaultGuildChannelId({guildId: 'guild', channels, selectedChannelId: 'general'})).toBe('general');
+	});
+
+	it('falls back when the remembered channel is gone', () => {
+		expect(pickDefaultGuildChannelId({guildId: 'guild', channels, selectedChannelId: 'deleted'})).toBe('rules');
+	});
+
+	it('falls back when the remembered channel is not navigable', () => {
+		expect(pickDefaultGuildChannelId({guildId: 'guild', channels, selectedChannelId: 'link'})).toBe('rules');
+		expect(pickDefaultGuildChannelId({guildId: 'guild', channels, selectedChannelId: 'category'})).toBe('rules');
+	});
+
+	it('falls back when the remembered channel belongs to another guild', () => {
+		const withForeign = [...channels, {id: 'other', type: ChannelTypes.GUILD_TEXT, position: 0, guildId: 'other'}];
+		expect(pickDefaultGuildChannelId({guildId: 'guild', channels: withForeign, selectedChannelId: 'other'})).toBe(
+			'rules',
+		);
+	});
+});

fluxer_app/src/features/messaging/utils/ChannelShared.ts

@@ -20,28 +20,15 @@ export function pickDefaultGuildChannelId({
 	guildId,
 	channels,
 	selectedChannelId,
-	systemChannelId,
-	rulesChannelId,
 }: {
 	guildId: string;
 	channels: ReadonlyArray<MinimalChannel>;
 	selectedChannelId?: string | null;
-	systemChannelId?: string | null;
-	rulesChannelId?: string | null;
 }): string | null {
-	if (!channels.length) return null;
-	const channelById = new Map(channels.map((channel) => [channel.id, channel]));
-	const isChannelInGuild = (channelId?: string | null) =>
-		channelId ? channelById.get(channelId)?.guildId === guildId : false;
-	if (isChannelInGuild(selectedChannelId)) {
-		return selectedChannelId!;
+	const viewable = filterViewableChannels(channels.filter((channel) => channel.guildId === guildId));
+	if (!viewable.length) return null;
+	if (selectedChannelId && viewable.some((channel) => channel.id === selectedChannelId)) {
+		return selectedChannelId;
 	}
-	if (isChannelInGuild(systemChannelId)) {
-		return systemChannelId!;
-	}
-	if (isChannelInGuild(rulesChannelId)) {
-		return rulesChannelId!;
-	}
-	const viewable = [...filterViewableChannels(channels)].sort(compareChannelPosition);
-	return viewable[0]?.id ?? null;
+	return viewable.sort(compareChannelPosition)[0].id;
 }