fix(app): keep search results in server order instead of per channel (#1777)

fluxer_app/src/features/channel/components/SearchResultGrouping.test.ts

@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import type {Message} from '@app/features/messaging/models/MessagingMessage';
+import {describe, expect, it} from 'vitest';
+import {
+	buildSearchResultGroups,
+	buildSearchResultGroupsByMessageId,
+	countSearchResultChannels,
+} from './SearchResultGrouping';
+
+const message = (id: string, channelId: string): Message => ({id, channelId}) as Message;
+
+describe('SearchResultGrouping', () => {
+	it('keeps the order the server returned instead of bucketing per channel', () => {
+		const groups = buildSearchResultGroups([
+			message('500', 'general'),
+			message('400', 'random'),
+			message('300', 'general'),
+		]);
+		expect(groups.map((group) => group.messages.map((result) => result.id))).toEqual([['500'], ['400'], ['300']]);
+		expect(groups.map((group) => group.channelId)).toEqual(['general', 'random', 'general']);
+	});
+
+	it('merges consecutive results from the same channel into one group', () => {
+		const groups = buildSearchResultGroups([
+			message('500', 'general'),
+			message('490', 'general'),
+			message('400', 'random'),
+		]);
+		expect(groups).toHaveLength(2);
+		expect(groups[0].messages.map((result) => result.id)).toEqual(['500', '490']);
+		expect(groups[1].messages.map((result) => result.id)).toEqual(['400']);
+	});
+
+	it('gives every group a unique key even when a channel appears more than once', () => {
+		const groups = buildSearchResultGroups([
+			message('500', 'general'),
+			message('400', 'random'),
+			message('300', 'general'),
+		]);
+		expect(new Set(groups.map((group) => group.key)).size).toBe(3);
+	});
+
+	it('indexes each message to the group it renders in', () => {
+		const groups = buildSearchResultGroups([
+			message('500', 'general'),
+			message('400', 'random'),
+			message('300', 'general'),
+		]);
+		const groupsByMessageId = buildSearchResultGroupsByMessageId(groups);
+		expect(groupsByMessageId.get('500')).toBe(groups[0]);
+		expect(groupsByMessageId.get('400')).toBe(groups[1]);
+		expect(groupsByMessageId.get('300')).toBe(groups[2]);
+	});
+
+	it('counts distinct channels rather than groups', () => {
+		const groups = buildSearchResultGroups([
+			message('500', 'general'),
+			message('400', 'random'),
+			message('300', 'general'),
+		]);
+		expect(countSearchResultChannels(groups)).toBe(2);
+		expect(countSearchResultChannels(buildSearchResultGroups([]))).toBe(0);
+	});
+});