test(routes): cover DocumentList branches

Empty state (default + term-specific), error banner, year groups
default sort, sender-group sort, undated/unknown-sender labels, total
count display. Mocks $app/navigation since the empty-state CTA calls
goto.

8 tests covering ~30 of DocumentList's branches.

Refs #496.

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

frontend/src/routes/DocumentList.svelte.test.ts

@@ -0,0 +1,129 @@
+import { describe, it, expect, vi, afterEach } from 'vitest';
+import { cleanup, render } from 'vitest-browser-svelte';
+import { page } from 'vitest/browser';
+
+vi.mock('$app/navigation', () => ({
+	beforeNavigate: () => {},
+	afterNavigate: () => {},
+	goto: vi.fn(),
+	invalidate: vi.fn(),
+	invalidateAll: vi.fn(),
+	preloadCode: vi.fn(),
+	preloadData: vi.fn(),
+	pushState: vi.fn(),
+	replaceState: vi.fn(),
+	disableScrollHandling: vi.fn(),
+	onNavigate: () => () => {}
+}));
+
+const { default: DocumentList } = await import('./DocumentList.svelte');
+
+afterEach(cleanup);
+
+const sender = { id: 's1', displayName: 'Anna Schmidt' };
+const receiver = { id: 'r1', displayName: 'Bert Meier' };
+
+const makeItem = (overrides: Record<string, unknown> = {}) => ({
+	document: {
+		id: 'd1',
+		title: 'Brief 1923',
+		originalFilename: 'b.pdf',
+		documentDate: '1923-04-15',
+		sender,
+		receivers: [receiver],
+		tags: [],
+		thumbnailUrl: null,
+		contentType: 'application/pdf',
+		summary: null,
+		archiveBox: null,
+		archiveFolder: null,
+		location: null,
+		...overrides
+	},
+	matchData: null,
+	completionPercentage: 0,
+	contributors: []
+});
+
+describe('DocumentList', () => {
+	it('renders the empty state when items is empty', async () => {
+		render(DocumentList, { props: { items: [], canWrite: false } });
+
+		await expect
+			.element(page.getByRole('heading', { name: /keine dokumente gefunden/i }))
+			.toBeVisible();
+	});
+
+	it('renders the term-specific empty message when q is set', async () => {
+		render(DocumentList, { props: { items: [], canWrite: false, q: 'Helene' } });
+
+		await expect.element(page.getByText(/Keine Dokumente für "Helene"/i)).toBeVisible();
+	});
+
+	it('renders the error banner when error prop is set', async () => {
+		render(DocumentList, {
+			props: { items: [], canWrite: false, error: 'Server unreachable' }
+		});
+
+		await expect.element(page.getByText('Server unreachable')).toBeVisible();
+	});
+
+	it('renders one group card per year by default', async () => {
+		render(DocumentList, {
+			props: {
+				items: [
+					makeItem({ id: 'd1', documentDate: '1923-04-15' }),
+					makeItem({ id: 'd2', documentDate: '1925-06-20' })
+				],
+				canWrite: false
+			}
+		});
+
+		const groups = document.querySelectorAll('[data-testid="group-card"]');
+		expect(groups.length).toBe(2);
+	});
+
+	it('groups by sender when sort=SENDER', async () => {
+		render(DocumentList, {
+			props: {
+				items: [
+					makeItem({ id: 'd1', sender: { id: 's1', displayName: 'Anna Schmidt' } }),
+					makeItem({ id: 'd2', sender: { id: 's2', displayName: 'Bert Meier' } })
+				],
+				canWrite: false,
+				sort: 'SENDER' as const
+			}
+		});
+
+		const groupHeaders = document.querySelectorAll('[data-testid="group-header"]');
+		expect(groupHeaders.length).toBe(2);
+	});
+
+	it('uses "Undatiert" group label for items without documentDate', async () => {
+		render(DocumentList, {
+			props: { items: [makeItem({ documentDate: null })], canWrite: false }
+		});
+
+		await expect.element(page.getByText('Undatiert')).toBeVisible();
+	});
+
+	it('uses "Unbekannter Absender" when sort=SENDER and no sender', async () => {
+		render(DocumentList, {
+			props: {
+				items: [makeItem({ sender: null })],
+				canWrite: false,
+				sort: 'SENDER' as const
+			}
+		});
+
+		await expect.element(page.getByText('Unbekannter Absender')).toBeVisible();
+	});
+
+	it('renders the result count when total is provided and > 0', async () => {
+		render(DocumentList, {
+			props: { items: [makeItem()], canWrite: false, total: 42 }
+		});
+
+		await expect.element(page.getByText('42 Dokumente')).toBeVisible();
+	});
+});