test(discussion): cover CommentMessage branches

Author + initials, comment body, edited label gated on updatedAt vs
createdAt, edit-mode textarea, delete button gated on isOwn, onDelete
callback wiring.

8 tests covering ~16 of CommentMessage's branches.

Refs #496.

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

frontend/src/lib/shared/discussion/CommentMessage.svelte.test.ts

@@ -0,0 +1,93 @@
+import { describe, it, expect, vi, afterEach } from 'vitest';
+import { cleanup, render } from 'vitest-browser-svelte';
+import { page } from 'vitest/browser';
+import CommentMessage from './CommentMessage.svelte';
+
+afterEach(cleanup);
+
+const baseMessage = (overrides: Record<string, unknown> = {}) => ({
+	id: 'm1',
+	authorId: 'u1',
+	authorName: 'Anna Schmidt',
+	content: 'Tolle Geschichte!',
+	createdAt: '2026-04-15T10:00:00Z',
+	updatedAt: '2026-04-15T10:00:00Z',
+	mentionDTOs: [] as unknown[],
+	...overrides
+});
+
+const baseProps = (overrides: Record<string, unknown> = {}) => ({
+	message: baseMessage(),
+	isOwn: false,
+	isEditing: false,
+	editText: '',
+	onEdit: () => {},
+	onDelete: () => {},
+	onEditTextChange: () => {},
+	onEditKeydown: () => {},
+	...overrides
+});
+
+describe('CommentMessage', () => {
+	it('renders the author name and avatar initials', async () => {
+		render(CommentMessage, { props: baseProps() });
+
+		await expect.element(page.getByText('Anna Schmidt')).toBeVisible();
+		await expect.element(page.getByText('AS')).toBeVisible();
+	});
+
+	it('renders the comment body', async () => {
+		render(CommentMessage, { props: baseProps() });
+
+		await expect.element(page.getByText('Tolle Geschichte!')).toBeVisible();
+	});
+
+	it('shows the edited label when updatedAt > createdAt', async () => {
+		render(CommentMessage, {
+			props: baseProps({
+				message: baseMessage({
+					createdAt: '2026-04-15T10:00:00Z',
+					updatedAt: '2026-04-15T11:00:00Z'
+				})
+			})
+		});
+
+		await expect.element(page.getByText('(Bearbeitet)')).toBeVisible();
+	});
+
+	it('hides the edited label when updatedAt equals createdAt', async () => {
+		render(CommentMessage, { props: baseProps() });
+
+		await expect.element(page.getByText('(Bearbeitet)')).not.toBeInTheDocument();
+	});
+
+	it('shows the textarea when in edit mode', async () => {
+		render(CommentMessage, {
+			props: baseProps({ isOwn: true, isEditing: true, editText: 'Editing content' })
+		});
+
+		const textarea = document.querySelector('textarea') as HTMLTextAreaElement;
+		expect(textarea.value).toBe('Editing content');
+	});
+
+	it('shows the delete button only when isOwn is true', async () => {
+		render(CommentMessage, { props: baseProps({ isOwn: true }) });
+
+		await expect.element(page.getByRole('button', { name: /löschen anna schmidt/i })).toBeVisible();
+	});
+
+	it('hides the delete button when isOwn is false', async () => {
+		render(CommentMessage, { props: baseProps() });
+
+		await expect.element(page.getByRole('button', { name: /löschen/i })).not.toBeInTheDocument();
+	});
+
+	it('calls onDelete when the delete button is clicked', async () => {
+		const onDelete = vi.fn();
+		render(CommentMessage, { props: baseProps({ isOwn: true, onDelete }) });
+
+		await page.getByRole('button', { name: /löschen anna schmidt/i }).click();
+
+		expect(onDelete).toHaveBeenCalledOnce();
+	});
+});