fix(app): show empty categories when hiding muted channels (#2460)

fluxer_app/src/features/app/components/layout/ChannelListContent.tsx

@@ -16,6 +16,7 @@ import {NullSpaceDropIndicator} from '@app/features/app/components/layout/NullSp
 import {ScrollIndicatorOverlay} from '@app/features/app/components/layout/ScrollIndicatorOverlay';
 import {type DragItem, DragItemType, type DropResult} from '@app/features/app/components/layout/types/DndTypes';
 import {
+	shouldShowCategoryWhenHidingMutedChannels,
 	shouldShowChannelInCollapsedCategory,
 	shouldShowChannelWhenHidingMutedChannels,
 } from '@app/features/app/components/layout/utils/ChannelListVisibility';
@@ -471,8 +472,10 @@ export const ChannelListContent = observer(({guild, scrollY}: {guild: Guild; scr
 		if (
 			hideMutedChannels &&
 			group.category &&
-			filteredTextChannels.length === 0 &&
+			!shouldShowCategoryWhenHidingMutedChannels({
-			filteredVoiceChannels.length === 0
+				hasChannels: group.textChannels.length > 0 || group.voiceChannels.length > 0,
+				hasVisibleChannels: filteredTextChannels.length > 0 || filteredVoiceChannels.length > 0,
+			})
 		) {
 			continue;
 		}

fluxer_app/src/features/app/components/layout/utils/ChannelListVisibility.test.ts

@@ -1,7 +1,11 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later
 
 import {describe, expect, it} from 'vitest';
-import {shouldShowChannelInCollapsedCategory, shouldShowChannelWhenHidingMutedChannels} from './ChannelListVisibility';
+import {
+	shouldShowCategoryWhenHidingMutedChannels,
+	shouldShowChannelInCollapsedCategory,
+	shouldShowChannelWhenHidingMutedChannels,
+} from './ChannelListVisibility';
 
 describe('shouldShowChannelWhenHidingMutedChannels', () => {
 	it('keeps muted channels with visible unread state so mentions are findable', () => {
@@ -57,6 +61,35 @@ describe('shouldShowChannelWhenHidingMutedChannels', () => {
 	});
 });
 
+describe('shouldShowCategoryWhenHidingMutedChannels', () => {
+	it('keeps a category that has no channels at all', () => {
+		expect(
+			shouldShowCategoryWhenHidingMutedChannels({
+				hasChannels: false,
+				hasVisibleChannels: false,
+			}),
+		).toBe(true);
+	});
+
+	it('hides a category whose channels were all filtered out as muted', () => {
+		expect(
+			shouldShowCategoryWhenHidingMutedChannels({
+				hasChannels: true,
+				hasVisibleChannels: false,
+			}),
+		).toBe(false);
+	});
+
+	it('keeps a category that still has visible channels', () => {
+		expect(
+			shouldShowCategoryWhenHidingMutedChannels({
+				hasChannels: true,
+				hasVisibleChannels: true,
+			}),
+		).toBe(true);
+	});
+});
+
 describe('shouldShowChannelInCollapsedCategory', () => {
 	it('keeps visible unread channels reachable in collapsed categories', () => {
 		expect(

fluxer_app/src/features/app/components/layout/utils/ChannelListVisibility.ts

@@ -16,6 +16,18 @@ export function shouldShowChannelWhenHidingMutedChannels({
 	return isSelected || isConnected || !isMuted || hasVisibleUnread;
 }
 
+export interface HiddenMutedCategoryVisibilityInput {
+	hasChannels: boolean;
+	hasVisibleChannels: boolean;
+}
+
+export function shouldShowCategoryWhenHidingMutedChannels({
+	hasChannels,
+	hasVisibleChannels,
+}: HiddenMutedCategoryVisibilityInput): boolean {
+	return !hasChannels || hasVisibleChannels;
+}
+
 export interface CollapsedCategoryChannelVisibilityInput {
 	isCategoryMuted: boolean;
 	isSelected: boolean;