test(conversations): add component tests for new features

Covers: empty state, swap button (visible/hidden, goto called with
swapped params), summary content, year dividers, and new document link
visibility gated by canWrite.

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

frontend/src/routes/conversations/page.svelte.spec.ts

@@ -0,0 +1,161 @@
+import { afterEach, describe, expect, it, vi } from 'vitest';
+import { cleanup, render } from 'vitest-browser-svelte';
+import { page } from 'vitest/browser';
+import Page from './+page.svelte';
+
+vi.mock('$app/navigation', () => ({ goto: vi.fn() }));
+
+afterEach(cleanup);
+
+// ─── Test data ────────────────────────────────────────────────────────────────
+
+const baseData = {
+	canWrite: true,
+	documents: [],
+	initialValues: { senderName: '', receiverName: '' },
+	filters: { senderId: '', receiverId: '', from: '', to: '', dir: 'DESC' as const }
+};
+
+const withPersons = {
+	...baseData,
+	filters: { ...baseData.filters, senderId: 'p1', receiverId: 'p2' }
+};
+
+const makeDoc = (overrides: Record<string, unknown> = {}) => ({
+	id: 'd1',
+	title: 'Testbrief',
+	originalFilename: 'testbrief.pdf',
+	status: 'UPLOADED' as const,
+	documentDate: '1923-04-12',
+	location: 'Berlin',
+	sender: { id: 'p1', firstName: 'Hans', lastName: 'Müller' },
+	receivers: [{ id: 'p2', firstName: 'Anna', lastName: 'Schmidt' }],
+	tags: [],
+	transcription: null,
+	filePath: null,
+	createdAt: '1923-04-12T00:00:00Z',
+	updatedAt: '1923-04-12T00:00:00Z',
+	...overrides
+});
+
+const withDocs = {
+	...withPersons,
+	documents: [makeDoc()]
+};
+
+// ─── Empty state ──────────────────────────────────────────────────────────────
+
+describe('Conversations page – empty state', () => {
+	it('shows the "select two persons" prompt when no persons are selected', async () => {
+		render(Page, { data: baseData });
+		await expect.element(page.getByText(/Wählen Sie zwei Personen aus/i)).toBeInTheDocument();
+	});
+
+	it('does not show the swap button when no persons are selected', async () => {
+		render(Page, { data: baseData });
+		await expect.element(page.getByTestId('conv-swap-btn')).not.toBeInTheDocument();
+	});
+
+	it('does not show the new document link when no persons are selected', async () => {
+		render(Page, { data: baseData });
+		await expect.element(page.getByTestId('conv-new-doc-link')).not.toBeInTheDocument();
+	});
+});
+
+// ─── No results ───────────────────────────────────────────────────────────────
+
+describe('Conversations page – no results', () => {
+	it('shows "no documents found" when both persons are selected but there are no documents', async () => {
+		render(Page, { data: withPersons });
+		await expect.element(page.getByText(/Keine Dokumente gefunden/i)).toBeInTheDocument();
+	});
+});
+
+// ─── Swap button ──────────────────────────────────────────────────────────────
+
+describe('Conversations page – swap button', () => {
+	it('shows the swap button when both persons are selected', async () => {
+		render(Page, { data: withPersons });
+		await expect.element(page.getByTestId('conv-swap-btn')).toBeInTheDocument();
+	});
+
+	it('calls goto with swapped sender and receiver when clicked', async () => {
+		const { goto } = await import('$app/navigation');
+		vi.mocked(goto).mockClear();
+		render(Page, { data: withPersons });
+		await page.getByTestId('conv-swap-btn').click();
+		expect(goto).toHaveBeenCalledWith(expect.stringContaining('senderId=p2'), expect.anything());
+		expect(goto).toHaveBeenCalledWith(expect.stringContaining('receiverId=p1'), expect.anything());
+	});
+});
+
+// ─── Summary ──────────────────────────────────────────────────────────────────
+
+describe('Conversations page – summary', () => {
+	it('shows document count and year range when documents are loaded', async () => {
+		const data = {
+			...withPersons,
+			documents: [
+				makeDoc({ documentDate: '1923-04-12' }),
+				makeDoc({ id: 'd2', documentDate: '1965-08-03' })
+			]
+		};
+		render(Page, { data });
+		const summary = page.getByTestId('conv-summary');
+		await expect.element(summary).toHaveTextContent('2');
+		await expect.element(summary).toHaveTextContent('1923');
+		await expect.element(summary).toHaveTextContent('1965');
+	});
+});
+
+// ─── Year dividers ────────────────────────────────────────────────────────────
+
+describe('Conversations page – year dividers', () => {
+	it('renders a year divider for the first document', async () => {
+		render(Page, { data: withDocs });
+		await expect.element(page.getByTestId('year-divider').first()).toHaveTextContent('1923');
+	});
+
+	it('renders a divider for each new year in the document list', async () => {
+		const data = {
+			...withPersons,
+			documents: [
+				makeDoc({ documentDate: '1923-04-12' }),
+				makeDoc({ id: 'd2', documentDate: '1965-08-03' })
+			]
+		};
+		render(Page, { data });
+		await expect.element(page.getByTestId('year-divider').first()).toHaveTextContent('1923');
+		await expect.element(page.getByTestId('year-divider').nth(1)).toHaveTextContent('1965');
+	});
+
+	it('does not render a second divider for documents from the same year', async () => {
+		const data = {
+			...withPersons,
+			documents: [
+				makeDoc({ documentDate: '1923-04-12' }),
+				makeDoc({ id: 'd2', documentDate: '1923-09-01' })
+			]
+		};
+		render(Page, { data });
+		// Only one divider for 1923; 1965 divider should not appear
+		await expect.element(page.getByTestId('year-divider').first()).toHaveTextContent('1923');
+		await expect.element(page.getByTestId('year-divider').nth(1)).not.toBeInTheDocument();
+	});
+});
+
+// ─── New document link ────────────────────────────────────────────────────────
+
+describe('Conversations page – new document link', () => {
+	it('shows the link with correct href for a write user', async () => {
+		render(Page, { data: { ...withDocs, canWrite: true } });
+		const link = page.getByTestId('conv-new-doc-link');
+		await expect.element(link).toBeInTheDocument();
+		await expect.element(link).toHaveAttribute('href', '/documents/new?senderId=p1&receiverId=p2');
+	});
+
+	it('hides the link for a read-only user', async () => {
+		render(Page, { data: { ...withDocs, canWrite: false } });
+		await expect.element(page.getByTestId('conv-new-doc-link')).not.toBeInTheDocument();
+	});
+});