feat: auto-save notes with debounced persistence

Notes are now automatically saved 2 seconds after the user stops editing,
preventing data loss when the browser tab is closed without closing the
editor first. A beforeunload handler provides an additional safety net.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/lib/components/NoteEditor.svelte

@@ -63,6 +63,77 @@
 	// svelte-ignore state_referenced_locally
 	let currentlyNew = $state(isNew);
 
+	// Auto-save: track last-saved state to detect real changes
+	let lastSavedTitle = note?.title ?? '';
+	let lastSavedContent = note?.content ?? '';
+	let lastSavedColor: NoteColor = note?.color ?? prefs.defaultNoteColor;
+	let lastSavedChecklistMode = note?.checklistMode ?? initialChecklistMode;
+	let isSaving = false;
+	let savingPromise: Promise<void> | null = null;
+	let autoSaveTimer: ReturnType<typeof setTimeout> | undefined;
+
+	function hasUnsavedChanges(): boolean {
+		return (
+			title !== lastSavedTitle ||
+			content !== lastSavedContent ||
+			color !== lastSavedColor ||
+			checklistMode !== lastSavedChecklistMode
+		);
+	}
+
+	async function performSave() {
+		if (isSaving) return;
+		if (!title.trim() && !content.trim()) return;
+		if (!hasUnsavedChanges()) return;
+
+		isSaving = true;
+		try {
+			if (currentlyNew) {
+				const created = await createNote({ title, content, color, checklistMode });
+				if (created) {
+					noteId = created.id;
+					currentlyNew = false;
+				}
+			} else if (noteId) {
+				await updateNote(noteId, { title, content, color, checklistMode });
+			}
+			lastSavedTitle = title;
+			lastSavedContent = content;
+			lastSavedColor = color;
+			lastSavedChecklistMode = checklistMode;
+		} finally {
+			isSaving = false;
+		}
+	}
+
+	// Debounced auto-save: triggers 2s after the user stops editing
+	$effect(() => {
+		const _t = title;
+		const _c = content;
+		const _col = color;
+		const _cm = checklistMode;
+
+		if (_t === lastSavedTitle && _c === lastSavedContent && _col === lastSavedColor && _cm === lastSavedChecklistMode) return;
+		if (!_t.trim() && !_c.trim()) return;
+
+		autoSaveTimer = setTimeout(() => {
+			savingPromise = performSave();
+		}, 2000);
+
+		return () => clearTimeout(autoSaveTimer);
+	});
+
+	// Safety net: save on tab close / navigation
+	$effect(() => {
+		function handleBeforeUnload() {
+			if (hasUnsavedChanges() && (title.trim() || content.trim())) {
+				performSave();
+			}
+		}
+		window.addEventListener('beforeunload', handleBeforeUnload);
+		return () => window.removeEventListener('beforeunload', handleBeforeUnload);
+	});
+
 	// svelte-ignore state_referenced_locally
 	let attachmentsList = $state<Attachment[]>(note?.attachments ?? []);
 
@@ -242,15 +313,18 @@
 	}
 
 	async function saveAndClose() {
+		clearTimeout(autoSaveTimer);
+		// Wait for any in-flight auto-save to finish
+		if (savingPromise) await savingPromise;
+
 		if (!title.trim() && !content.trim()) {
 			onClose();
 			return;
 		}
 
-		if (currentlyNew) {
+		// Final save if auto-save hasn't caught up yet
-			await createNote({ title, content, color, checklistMode });
+		if (hasUnsavedChanges()) {
-		} else if (noteId) {
+			await performSave();
-			await updateNote(noteId, { title, content, color, checklistMode });
 		}
 		onClose();
 	}
@@ -258,18 +332,14 @@
 	/** Auto-save a new note without closing, returns the new note ID */
 	async function autoSave(): Promise<string | null> {
 		if (!currentlyNew) return noteId;
-		const created = await createNote({
+		clearTimeout(autoSaveTimer);
-			title: title || 'Untitled',
+		if (savingPromise) await savingPromise;
-			content,
+		// For feature-triggered saves (image upload, share), use 'Untitled' fallback
-			color,
+		const prevTitle = title;
-			checklistMode
+		if (!title.trim()) title = 'Untitled';
-		});
+		await performSave();
-		if (created) {
+		if (!prevTitle.trim()) title = prevTitle;
-			noteId = created.id;
+		return noteId;
-			currentlyNew = false;
-			return created.id;
-		}
-		return null;
 	}
 
 	async function toggleImageUpload() {

tests/e2e/auto-save.spec.ts

@@ -0,0 +1,83 @@
+import { test, expect, noteCard, createNote } from './helpers/fixtures.js';
+
+test.describe('Auto-save', () => {
+	test('Scenario: New note is auto-saved without closing the editor', async ({ authenticatedPage: page }) => {
+		// When the user starts a new note and types a title and content
+		await page.getByTestId('new-note-btn').click();
+		await page.getByTestId('note-title-input').fill('Auto-saved Note');
+		const editor = page.getByTestId('tiptap-editor').locator('.tiptap');
+		await editor.click();
+		await editor.pressSequentially('This should be saved automatically');
+
+		// Then the note is persisted after the auto-save delay (2s debounce)
+		await expect(noteCard(page, 'Auto-saved Note')).toBeVisible({ timeout: 5000 });
+
+		// And closing the editor preserves the note
+		await page.getByTestId('close-editor-btn').click();
+		await expect(noteCard(page, 'Auto-saved Note')).toBeVisible();
+	});
+
+	test('Scenario: Edits to an existing note are auto-saved', async ({ authenticatedPage: page }) => {
+		// Given a note titled "Edit Me" exists
+		await createNote(page, 'Edit Me', 'Original content');
+
+		// When the user opens the note and changes the title
+		await noteCard(page, 'Edit Me').click();
+		await page.getByTestId('note-title-input').clear();
+		await page.getByTestId('note-title-input').fill('Edited Title');
+
+		// Then the updated title is auto-saved after the debounce delay
+		// Wait for the API call that confirms the save
+		await page.waitForResponse(
+			(res) => res.url().includes('/api/notes/') && res.request().method() === 'PATCH',
+			{ timeout: 5000 }
+		);
+
+		// And the note card reflects the change while editor is still open
+		await expect(noteCard(page, 'Edited Title')).toBeVisible();
+
+		// Cleanup: close the editor
+		await page.getByTestId('close-editor-btn').click();
+	});
+
+	test('Scenario: Empty note is not auto-saved', async ({ authenticatedPage: page }) => {
+		// When the user opens a new note but leaves it empty
+		await page.getByTestId('new-note-btn').click();
+
+		// And waits longer than the auto-save delay
+		await page.waitForTimeout(3000);
+
+		// Then no note card appears in the list
+		const noteCards = page.locator('[data-testid="note-card"]');
+		const countBefore = await noteCards.count();
+
+		// Close the empty editor
+		await page.getByTestId('close-editor-btn').click();
+
+		// And no new note was created
+		const countAfter = await noteCards.count();
+		expect(countAfter).toBe(countBefore);
+	});
+
+	test('Scenario: Auto-save persists note across page reload', async ({ authenticatedPage: page }) => {
+		// When the user creates a note and waits for auto-save
+		await page.getByTestId('new-note-btn').click();
+		await page.getByTestId('note-title-input').fill('Survive Reload');
+		const editor = page.getByTestId('tiptap-editor').locator('.tiptap');
+		await editor.click();
+		await editor.pressSequentially('Content that survives');
+
+		// Wait for auto-save to fire
+		await page.waitForResponse(
+			(res) => res.url().includes('/api/notes') && res.request().method() === 'POST',
+			{ timeout: 5000 }
+		);
+
+		// When the page is reloaded without closing the editor
+		await page.reload();
+		await page.waitForLoadState('networkidle');
+
+		// Then the note is still visible
+		await expect(noteCard(page, 'Survive Reload')).toBeVisible();
+	});
+});