Download updates automatically on startup

Startup still checks after 5s, but now also downloads and stages the
install. Relaunch stays a user action so unsaved work is not interrupted.
Manual "check for updates" still only probes.

Author: gaoyu06

docs/updater.md

@@ -45,7 +45,10 @@ tauri-action 会自动：
 2. 汇总各平台的版本号、下载地址和签名，生成 `latest.json` 并上传到该 Release。
 
 之后已安装的客户端访问
-`releases/latest/download/latest.json` 即可发现并下载新版本。
+`releases/latest/download/latest.json` 即可发现新版本。应用启动约 5 秒后会自动检查，
+发现更新后自动下载并安装到待应用状态；为了避免中断未保存工作，应用不会自动退出，
+用户可在设置 → 概览 →「应用更新」中点击「重启并安装」完成切换。手动点击「检查更新」
+仍只检查版本，不会自动下载。
 
 ## 3. 发布流程
 

src/lib/updater.svelte.ts

@@ -5,7 +5,7 @@ import { relaunch } from '@tauri-apps/plugin-process';
 
 export type UpdatePhase = 'idle' | 'checking' | 'latest' | 'available' | 'downloading' | 'ready' | 'error';
 
-class UpdaterState {
+export class UpdaterState {
 	phase = $state<UpdatePhase>('idle');
 	/** 可用的新版本号（phase 为 available/downloading/ready 时有效）。 */
 	version = $state('');
@@ -19,16 +19,20 @@ class UpdaterState {
 		return this.phase === 'available' || this.phase === 'downloading' || this.phase === 'ready';
 	}
 
-	/** 检查更新。`silent` 用于启动时的后台检查：失败/无更新都保持安静。 */
-	async check(silent = false) {
+	/**
+	 * Check for updates. Startup checks can pass `autoInstall` to download and
+	 * install immediately. Relaunch stays user-controlled to avoid lost work.
+	 */
+	async check(silent = false, autoInstall = false) {
 		if (this.phase === 'checking' || this.phase === 'downloading' || this.phase === 'ready') return;
-		if (!silent) this.phase = 'checking';
+		this.phase = 'checking';
 		try {
 			const u = await check();
 			if (u) {
 				this.#update = u;
 				this.version = u.version;
 				this.phase = 'available';
+				if (autoInstall) await this.download();
 			} else {
 				this.phase = silent ? 'idle' : 'latest';
 			}

src/lib/updater.test.ts

@@ -0,0 +1,69 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+import { UpdaterState } from './updater.svelte';
+
+const { check, relaunch } = vi.hoisted(() => ({ check: vi.fn(), relaunch: vi.fn() }));
+
+vi.mock('@tauri-apps/plugin-updater', () => ({ check }));
+vi.mock('@tauri-apps/plugin-process', () => ({ relaunch }));
+
+describe('UpdaterState', () => {
+	beforeEach(() => {
+		check.mockReset();
+		relaunch.mockReset();
+	});
+
+	const update = () => ({
+		version: '0.3.2',
+		downloadAndInstall: vi.fn().mockResolvedValue(undefined)
+	});
+
+	it('automatically downloads and installs a silent startup update', async () => {
+		const u = update();
+		check.mockResolvedValue(u);
+		const state = new UpdaterState();
+
+		await state.check(true, true);
+
+		expect(u.downloadAndInstall).toHaveBeenCalledOnce();
+		expect(state.phase).toBe('ready');
+		expect(state.version).toBe('0.3.2');
+	});
+
+	it('keeps manual checks download-free until the user starts the download', async () => {
+		const u = update();
+		check.mockResolvedValue(u);
+		const state = new UpdaterState();
+
+		await state.check();
+
+		expect(u.downloadAndInstall).not.toHaveBeenCalled();
+		expect(state.phase).toBe('available');
+	});
+
+	it('does not start a second check while an update is downloading', async () => {
+		const u = update();
+		let resolveDownload!: () => void;
+		u.downloadAndInstall.mockReturnValue(new Promise<void>((resolve) => (resolveDownload = resolve)));
+		check.mockResolvedValue(u);
+		const state = new UpdaterState();
+
+		const first = state.check(true, true);
+		await vi.waitFor(() => expect(state.phase).toBe('downloading'));
+		await state.check(true, true);
+		expect(check).toHaveBeenCalledOnce();
+		resolveDownload();
+		await first;
+	});
+
+	it('surfaces an automatic install failure without pretending it is ready', async () => {
+		const u = update();
+		u.downloadAndInstall.mockRejectedValue(new Error('signature mismatch'));
+		check.mockResolvedValue(u);
+		const state = new UpdaterState();
+
+		await state.check(true, true);
+
+		expect(state.phase).toBe('error');
+		expect(state.error).toContain('signature mismatch');
+	});
+});

src/routes/+page.svelte

@@ -811,8 +811,8 @@
 				for (const u of urls) handleDeepLink(u);
 			});
 			cleanups.push(undeep);
-			// 启动约 5 秒后静默检查一次更新；有新版本时设置入口显示小圆点。
-			const updateTimer = setTimeout(() => updater.check(true), 5000);
+			// Check GitHub after startup and install updates; relaunch stays user-controlled.
+			const updateTimer = setTimeout(() => updater.check(true, true), 5000);
 			cleanups.push(() => clearTimeout(updateTimer));
 			loadProviders();
 			readAuthProviders()