refactor: move notification domain to lib/notification/

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/lib/notification/notifications.svelte.spec.ts

@@ -0,0 +1,200 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import type { NotificationItem } from '$lib/notification/notifications';
+
+let lastEventSource: MockEventSource | null = null;
+let eventSourceCount = 0;
+
+class MockEventSource {
+	static CONNECTING = 0;
+	static OPEN = 1;
+	static CLOSED = 2;
+
+	readyState = MockEventSource.CONNECTING;
+	onopen: (() => void) | null = null;
+	onerror: (() => void | Promise<void>) | null = null;
+	close = vi.fn();
+	private listeners: Record<string, ((e: MessageEvent) => void)[]> = {};
+
+	constructor() {
+		eventSourceCount += 1;
+		// eslint-disable-next-line @typescript-eslint/no-this-alias
+		lastEventSource = this;
+	}
+
+	addEventListener(type: string, fn: (e: MessageEvent) => void) {
+		if (!this.listeners[type]) this.listeners[type] = [];
+		this.listeners[type].push(fn);
+	}
+
+	simulate(type: string, data: string) {
+		const event = new MessageEvent(type, { data });
+		for (const fn of this.listeners[type] ?? []) {
+			fn(event);
+		}
+	}
+}
+
+vi.stubGlobal('EventSource', MockEventSource);
+
+const mockFetch = vi.fn();
+vi.stubGlobal('fetch', mockFetch);
+
+const { notificationStore, __resetForTest, __setNavigateForTest } =
+	await import('./notifications.svelte');
+
+let navigateSpy: ReturnType<typeof vi.fn>;
+
+beforeEach(() => {
+	mockFetch.mockReset();
+	mockFetch.mockResolvedValue(new Response(JSON.stringify({ count: 0 }), { status: 200 }));
+	lastEventSource = null;
+	eventSourceCount = 0;
+	navigateSpy = vi.fn();
+	__setNavigateForTest(navigateSpy);
+	__resetForTest();
+});
+
+function makeNotification(overrides: Partial<NotificationItem> = {}): NotificationItem {
+	return {
+		id: 'n1',
+		type: 'REPLY',
+		actorName: 'Hans',
+		documentId: 'doc-1',
+		documentTitle: null,
+		referenceId: 'ref-1',
+		annotationId: null,
+		read: false,
+		createdAt: new Date().toISOString(),
+		...overrides
+	};
+}
+
+describe('notificationStore (singleton)', () => {
+	it('opens a single EventSource across multiple init() calls', () => {
+		notificationStore.init();
+		notificationStore.init();
+		notificationStore.init();
+
+		expect(eventSourceCount).toBe(1);
+	});
+
+	it('closes the EventSource only after every init() is matched with destroy()', () => {
+		notificationStore.init();
+		notificationStore.init();
+		const es = lastEventSource!;
+
+		notificationStore.destroy();
+		expect(es.close).not.toHaveBeenCalled();
+
+		notificationStore.destroy();
+		expect(es.close).toHaveBeenCalledTimes(1);
+	});
+
+	it('reopens a fresh EventSource after full teardown', () => {
+		notificationStore.init();
+		notificationStore.destroy();
+		notificationStore.init();
+
+		expect(eventSourceCount).toBe(2);
+	});
+
+	it('SSE notification event prepends notification and increments unreadCount', () => {
+		notificationStore.init();
+
+		const notification = makeNotification({ id: 'sse-1', read: false });
+		lastEventSource!.simulate('notification', JSON.stringify(notification));
+
+		expect(notificationStore.notifications[0].id).toBe('sse-1');
+		expect(notificationStore.unreadCount).toBe(1);
+	});
+
+	it('markAllRead resets unreadCount', async () => {
+		mockFetch.mockResolvedValue(new Response(null, { status: 200 }));
+		await notificationStore.markAllRead();
+
+		expect(mockFetch).toHaveBeenCalledWith('/api/notifications/read-all', { method: 'POST' });
+		expect(notificationStore.unreadCount).toBe(0);
+	});
+});
+
+describe('notificationStore onerror handler', () => {
+	it('redirects to /login when readyState is CLOSED and server returns 401', async () => {
+		mockFetch.mockResolvedValue(new Response(null, { status: 401 }));
+		notificationStore.init();
+		const es = lastEventSource!;
+		es.readyState = MockEventSource.CLOSED;
+
+		await es.onerror?.();
+
+		expect(navigateSpy).toHaveBeenCalledWith('/login');
+	});
+
+	it('does not redirect when readyState is CLOSED and session is still valid', async () => {
+		notificationStore.init();
+		const es = lastEventSource!;
+		es.readyState = MockEventSource.CLOSED;
+
+		await es.onerror?.();
+
+		expect(navigateSpy).not.toHaveBeenCalled();
+	});
+
+	it('does not close or redirect before the error threshold when readyState is CONNECTING', async () => {
+		notificationStore.init();
+		const es = lastEventSource!;
+		es.readyState = MockEventSource.CONNECTING;
+
+		await es.onerror?.();
+		await es.onerror?.();
+
+		expect(es.close).not.toHaveBeenCalled();
+		expect(navigateSpy).not.toHaveBeenCalled();
+	});
+
+	it('closes and redirects after 3 consecutive CONNECTING errors when session returns 401', async () => {
+		mockFetch.mockResolvedValue(new Response(null, { status: 401 }));
+		notificationStore.init();
+		const es = lastEventSource!;
+		es.readyState = MockEventSource.CONNECTING;
+
+		await es.onerror?.();
+		await es.onerror?.();
+		await es.onerror?.();
+
+		expect(es.close).toHaveBeenCalledTimes(1);
+		expect(navigateSpy).toHaveBeenCalledWith('/login');
+	});
+
+	it('closes but does not redirect after threshold when session is still valid', async () => {
+		notificationStore.init();
+		const es = lastEventSource!;
+		es.readyState = MockEventSource.CONNECTING;
+
+		await es.onerror?.();
+		await es.onerror?.();
+		await es.onerror?.();
+
+		expect(es.close).toHaveBeenCalledTimes(1);
+		expect(navigateSpy).not.toHaveBeenCalled();
+	});
+
+	it('resets error count after a successful reconnect (onopen)', async () => {
+		notificationStore.init();
+		const es = lastEventSource!;
+		es.readyState = MockEventSource.CONNECTING;
+
+		// Two errors — not yet at threshold
+		await es.onerror?.();
+		await es.onerror?.();
+
+		// Successful reconnect resets counter
+		es.onopen?.();
+
+		// Two more errors — should still be below threshold
+		await es.onerror?.();
+		await es.onerror?.();
+
+		expect(es.close).not.toHaveBeenCalled();
+		expect(navigateSpy).not.toHaveBeenCalled();
+	});
+});