fix(app): stop the quick switcher list rebuilding while you navigate (#1881)

fluxer_app/src/features/search/state/QuickSwitcherSelection.test.ts

@@ -1,12 +1,15 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later
 
-import {resolveRecomputedSelectedIndex} from '@app/features/search/state/QuickSwitcherSelection';
+import {hasSameResultIdentity, resolveRecomputedSelectedIndex} from '@app/features/search/state/QuickSwitcherSelection';
 import type {QuickSwitcherResult} from '@app/features/search/state/QuickSwitcherTypes';
 import {QuickSwitcherResultTypes} from '@fluxer/constants/src/QuickSwitcherConstants';
 import {describe, expect, it} from 'vitest';
 
 const result = (type: QuickSwitcherResult['type'], id: string) => ({type, id}) as QuickSwitcherResult;
 
+const labelled = (type: QuickSwitcherResult['type'], id: string, title: string, subtitle?: string) =>
+	({type, id, title, subtitle}) as QuickSwitcherResult;
+
 describe('resolveRecomputedSelectedIndex', () => {
 	it('follows the focused result when the list is reordered', () => {
 		const previous = result(QuickSwitcherResultTypes.TEXT_CHANNEL, 'c3');
@@ -44,3 +47,86 @@ describe('resolveRecomputedSelectedIndex', () => {
 		expect(resolveRecomputedSelectedIndex(undefined, [result(QuickSwitcherResultTypes.GUILD, 'g')], 0)).toBe(0);
 	});
 });
+
+describe('hasSameResultIdentity', () => {
+	it('treats a rebuilt list of the same rows in the same order as unchanged', () => {
+		const previous = [
+			result(QuickSwitcherResultTypes.HEADER, 'people'),
+			result(QuickSwitcherResultTypes.USER, 'u1'),
+			result(QuickSwitcherResultTypes.TEXT_CHANNEL, 'c1'),
+		];
+		const next = [
+			result(QuickSwitcherResultTypes.HEADER, 'people'),
+			result(QuickSwitcherResultTypes.USER, 'u1'),
+			result(QuickSwitcherResultTypes.TEXT_CHANNEL, 'c1'),
+		];
+		expect(hasSameResultIdentity(previous, next)).toBe(true);
+	});
+
+	it('detects a reorder', () => {
+		const previous = [
+			result(QuickSwitcherResultTypes.TEXT_CHANNEL, 'c1'),
+			result(QuickSwitcherResultTypes.TEXT_CHANNEL, 'c2'),
+		];
+		const next = [
+			result(QuickSwitcherResultTypes.TEXT_CHANNEL, 'c2'),
+			result(QuickSwitcherResultTypes.TEXT_CHANNEL, 'c1'),
+		];
+		expect(hasSameResultIdentity(previous, next)).toBe(false);
+	});
+
+	it('detects an insertion', () => {
+		const previous = [result(QuickSwitcherResultTypes.TEXT_CHANNEL, 'c1')];
+		const next = [
+			result(QuickSwitcherResultTypes.TEXT_CHANNEL, 'c1'),
+			result(QuickSwitcherResultTypes.TEXT_CHANNEL, 'c2'),
+		];
+		expect(hasSameResultIdentity(previous, next)).toBe(false);
+	});
+
+	it('detects a row whose type changed under the same id', () => {
+		const previous = [result(QuickSwitcherResultTypes.TEXT_CHANNEL, '42')];
+		const next = [result(QuickSwitcherResultTypes.VOICE_CHANNEL, '42')];
+		expect(hasSameResultIdentity(previous, next)).toBe(false);
+	});
+
+	it('treats two empty lists as unchanged', () => {
+		expect(hasSameResultIdentity([], [])).toBe(true);
+	});
+
+	it('detects a renamed row so the open list repaints', () => {
+		const previous = [labelled(QuickSwitcherResultTypes.TEXT_CHANNEL, 'c1', 'general')];
+		const next = [labelled(QuickSwitcherResultTypes.TEXT_CHANNEL, 'c1', 'general-chat')];
+		expect(hasSameResultIdentity(previous, next)).toBe(false);
+	});
+
+	it('detects a changed subtitle under an unchanged title', () => {
+		const previous = [labelled(QuickSwitcherResultTypes.USER, 'u1', 'ada', 'ada#0001')];
+		const next = [labelled(QuickSwitcherResultTypes.USER, 'u1', 'ada', 'ada#0002')];
+		expect(hasSameResultIdentity(previous, next)).toBe(false);
+	});
+
+	it('detects a subtitle that appeared where there was none', () => {
+		const previous = [labelled(QuickSwitcherResultTypes.USER, 'u1', 'ada')];
+		const next = [labelled(QuickSwitcherResultTypes.USER, 'u1', 'ada', 'ada#0001')];
+		expect(hasSameResultIdentity(previous, next)).toBe(false);
+	});
+
+	it('detects a renamed section header', () => {
+		const previous = [labelled(QuickSwitcherResultTypes.HEADER, 'people', 'People')];
+		const next = [labelled(QuickSwitcherResultTypes.HEADER, 'people', 'Personnes')];
+		expect(hasSameResultIdentity(previous, next)).toBe(false);
+	});
+
+	it('still treats an identically labelled rebuild as unchanged', () => {
+		const previous = [
+			labelled(QuickSwitcherResultTypes.HEADER, 'people', 'People'),
+			labelled(QuickSwitcherResultTypes.USER, 'u1', 'ada', 'ada#0001'),
+		];
+		const next = [
+			labelled(QuickSwitcherResultTypes.HEADER, 'people', 'People'),
+			labelled(QuickSwitcherResultTypes.USER, 'u1', 'ada', 'ada#0001'),
+		];
+		expect(hasSameResultIdentity(previous, next)).toBe(true);
+	});
+});