diff --git a/frontend/src/lib/shared/discussion/MentionDropdown.svelte.test.ts b/frontend/src/lib/shared/discussion/MentionDropdown.svelte.test.ts
new file mode 100644
index 00000000..46e2da86
--- /dev/null
+++ b/frontend/src/lib/shared/discussion/MentionDropdown.svelte.test.ts
@@ -0,0 +1,106 @@
+import { describe, it, expect, vi, afterEach } from 'vitest';
+import { cleanup, render } from 'vitest-browser-svelte';
+import { page } from 'vitest/browser';
+import MentionDropdown from './MentionDropdown.svelte';
+
+afterEach(cleanup);
+
+const makePerson = (id: string, name: string, overrides: Record<string, unknown> = {}) => ({
+	id,
+	firstName: name.split(' ')[0] ?? null,
+	lastName: name.split(' ').slice(1).join(' ') || name,
+	displayName: name,
+	birthYear: null as number | null,
+	deathYear: null as number | null,
+	...overrides
+});
+
+const baseModel = (overrides: Record<string, unknown> = {}) => ({
+	items: [] as ReturnType<typeof makePerson>[],
+	command: vi.fn(),
+	clientRect: () => new DOMRect(100, 100, 0, 24),
+	...overrides
+});
+
+describe('MentionDropdown', () => {
+	it('renders the listbox with the mention label', async () => {
+		render(MentionDropdown, { props: { model: baseModel() } });
+
+		await expect.element(page.getByRole('listbox', { name: /person verlinken/i })).toBeVisible();
+	});
+
+	it('renders the empty placeholder when items is empty', async () => {
+		render(MentionDropdown, { props: { model: baseModel() } });
+
+		await expect.element(page.getByText('Keine Personen gefunden')).toBeVisible();
+	});
+
+	it('shows the create-new escape hatch link in the empty state', async () => {
+		render(MentionDropdown, { props: { model: baseModel() } });
+
+		const link = (await page
+			.getByRole('link', { name: /neue person anlegen/i })
+			.element()) as HTMLAnchorElement;
+		expect(link.href).toContain('/persons/new');
+		expect(link.target).toBe('_blank');
+		expect(link.rel).toContain('noopener');
+	});
+
+	it('renders one option per item when populated', async () => {
+		render(MentionDropdown, {
+			props: {
+				model: baseModel({
+					items: [makePerson('p1', 'Anna Schmidt'), makePerson('p2', 'Bert Meier')]
+				})
+			}
+		});
+
+		await expect.element(page.getByText('Anna Schmidt')).toBeVisible();
+		await expect.element(page.getByText('Bert Meier')).toBeVisible();
+	});
+
+	it('marks the first item as aria-selected by default', async () => {
+		render(MentionDropdown, {
+			props: { model: baseModel({ items: [makePerson('p1', 'Anna Schmidt')] }) }
+		});
+
+		const option = document.querySelector('[role="option"]');
+		expect(option?.getAttribute('aria-selected')).toBe('true');
+	});
+
+	it('renders the life-date range when birthYear or deathYear is present', async () => {
+		render(MentionDropdown, {
+			props: {
+				model: baseModel({
+					items: [makePerson('p1', 'Anna', { birthYear: 1899, deathYear: 1972 })]
+				})
+			}
+		});
+
+		await expect.element(page.getByText(/1899/)).toBeVisible();
+	});
+
+	it('falls back to a default position when clientRect returns null', async () => {
+		render(MentionDropdown, {
+			props: {
+				model: baseModel({ clientRect: () => null })
+			}
+		});
+
+		const dropdown = document.querySelector('[role="listbox"]') as HTMLElement;
+		expect(dropdown.style.left).toBe('0px');
+	});
+
+	it('positions itself based on the clientRect callback', async () => {
+		render(MentionDropdown, {
+			props: {
+				model: baseModel({
+					clientRect: () => new DOMRect(123, 200, 50, 24)
+				})
+			}
+		});
+
+		const dropdown = document.querySelector('[role="listbox"]') as HTMLElement;
+		expect(dropdown.style.left).toBe('123px');
+	});
+});