fix(sw): オフライン時のfetch timeout処理を実装 (#16952)

* fix(sw): implement fetch timeout handling for navigation and offline content

* fix(sw): increase fetch timeout

* fix(sw): improve fetch timeout handling for i18n content

* fix(sw): 結局、fetchを通るかCacheがhitするはずなので、i18nのところはいらない

* fix(sw): 400番台のエラーを無条件でオフラインページにしていたのを修正

* 間違えた

* i18nもtimeoutが必要

* import sortingを修正

* import sortingを修正

* Fix: Frontend のsharedにはアクセスできないじゃん...

* SPDX

* Update CHANGELOG.md

* Update packages/sw/src/scripts/lang.ts

Co-authored-by: かっこかり <67428053+kakkokari-gtyih@users.noreply.github.com>

* Update packages/sw/src/sw.ts

Co-authored-by: かっこかり <67428053+kakkokari-gtyih@users.noreply.github.com>

* Update CHANGELOG.md

Co-authored-by: かっこかり <67428053+kakkokari-gtyih@users.noreply.github.com>

---------

Co-authored-by: かっこかり <67428053+kakkokari-gtyih@users.noreply.github.com>

3 files changed, 69 insertions, 27 deletions

diff --git a/packages/sw/src/const.ts b/packages/sw/src/const.ts
new file mode 100644
index 0000000000..9dd9bad30f
--- /dev/null
+++ b/packages/sw/src/const.ts
@@ -0,0 +1,6 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+export const FETCH_TIMEOUT_MS = 10000;
diff --git a/packages/sw/src/scripts/lang.ts b/packages/sw/src/scripts/lang.ts
index 40b6aa4e7b..63ac4ce399 100644
--- a/packages/sw/src/scripts/lang.ts
+++ b/packages/sw/src/scripts/lang.ts
@@ -8,6 +8,7 @@
  */
 import { get, set } from 'idb-keyval';
 import { I18n } from '@@/js/i18n.js';
+import { FETCH_TIMEOUT_MS } from '@/const.js';
 import type { Locale } from 'i18n';
 
 class SwLang {
@@ -37,11 +38,21 @@ class SwLang {
 
 		// _DEV_がtrueの場合は常に最新化
 		if (!localeRes || _DEV_) {
-			localeRes = await fetch(localeUrl);
-			const clone = localeRes.clone();
-			if (!clone.clone().ok) throw new Error('locale fetching error');
+			const controller = new AbortController();
+			const timeout = globalThis.setTimeout(() => {
+				controller.abort('locale-fetch-timeout');
+			}, FETCH_TIMEOUT_MS);
 
-			caches.open(this.cacheName).then(cache => cache.put(localeUrl, clone));
+			try {
+				localeRes = await fetch(localeUrl, { signal: controller.signal });
+
+				const clone = localeRes.clone();
+				if (!clone.clone().ok) throw new Error('locale fetching error');
+
+				caches.open(this.cacheName).then(cache => cache.put(localeUrl, clone));
+			} finally {
+				globalThis.clearTimeout(timeout);
+			}
 		}
 
 		return new I18n<Locale>(await localeRes.json());
diff --git a/packages/sw/src/sw.ts b/packages/sw/src/sw.ts
index 5cece73401..21017f8241 100644
--- a/packages/sw/src/sw.ts
+++ b/packages/sw/src/sw.ts
@@ -5,6 +5,7 @@
 
 import { get } from 'idb-keyval';
 import * as Misskey from 'misskey-js';
+import { FETCH_TIMEOUT_MS } from '@/const.js';
 import type { PushNotificationDataMap } from '@/types.js';
 import type { I18n } from '@@/js/i18n.js';
 import type { Locale } from 'i18n';
@@ -12,6 +13,52 @@ import { createEmptyNotification, createNotification } from '@/scripts/create-no
 import { swLang } from '@/scripts/lang.js';
 import * as swos from '@/scripts/operations.js';
 
+async function respondToNavigation(request: Request): Promise<Response> {
+	const controller = new AbortController();
+	const timeout = globalThis.setTimeout(() => {
+		controller.abort('navigation-timeout');
+	}, FETCH_TIMEOUT_MS);
+
+	try {
+		const response = await fetch(request, { signal: controller.signal });
+
+		if (response?.status && response.status < 500) return response;
+		if (response?.type === 'opaqueredirect') return response;
+	} catch (error) {
+		if (_DEV_) {
+			console.warn('navigation fetch failed; showing offline page', error);
+		}
+	} finally {
+		globalThis.clearTimeout(timeout);
+	}
+
+	// Only show offline page when network request actually fails
+	const html = await offlineContentHTML();
+	return new Response(html, {
+		status: 200,
+		headers: {
+			'content-type': 'text/html',
+		},
+	});
+}
+
+async function offlineContentHTML() {
+	let i18n: Partial<I18n<Locale>>;
+	try {
+		i18n = await (swLang.i18n ?? await swLang.fetchLocale()) as Partial<I18n<Locale>>;
+	} catch {
+		i18n = {};
+	}
+
+	const messages = {
+		title: i18n.ts?._offlineScreen.title ?? 'Offline - Could not connect to server',
+		header: i18n.ts?._offlineScreen.header ?? 'Could not connect to server',
+		reload: i18n.ts?.reload ?? 'Reload',
+	};
+
+	return `<!DOCTYPE html><html lang="ja"><head><meta charset="UTF-8"><meta content="width=device-width,initial-scale=1"name="viewport"><title>${messages.title}</title><style>body{background-color:#0c1210;color:#dee7e4;font-family:Hiragino Maru Gothic Pro,BIZ UDGothic,Roboto,HelveticaNeue,Arial,sans-serif;line-height:1.35;display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:100vh;margin:0;padding:24px;box-sizing:border-box}.icon{max-width:120px;width:100%;height:auto;margin-bottom:20px;}.message{text-align:center;font-size:20px;font-weight:700;margin-bottom:20px}.version{text-align:center;font-size:90%;margin-bottom:20px}button{padding:7px 14px;min-width:100px;font-weight:700;font-family:Hiragino Maru Gothic Pro,BIZ UDGothic,Roboto,HelveticaNeue,Arial,sans-serif;line-height:1.35;border-radius:99rem;background-color:#b4e900;color:#192320;border:none;cursor:pointer;-webkit-tap-highlight-color:transparent}button:hover{background-color:#c6ff03}</style></head><body><svg class="icon"fill="none"height="24"stroke="currentColor"stroke-linecap="round"stroke-linejoin="round"stroke-width="2"viewBox="0 0 24 24"width="24"xmlns="http://www.w3.org/2000/svg"><path d="M0 0h24v24H0z"fill="none"stroke="none"/><path d="M9.58 5.548c.24 -.11 .492 -.207 .752 -.286c1.88 -.572 3.956 -.193 5.444 1c1.488 1.19 2.162 3.007 1.77 4.769h.99c1.913 0 3.464 1.56 3.464 3.486c0 .957 -.383 1.824 -1.003 2.454m-2.997 1.033h-11.343c-2.572 -.004 -4.657 -2.011 -4.657 -4.487c0 -2.475 2.085 -4.482 4.657 -4.482c.13 -.582 .37 -1.128 .7 -1.62"/><path d="M3 3l18 18"/></svg><div class="message">${messages.header}</div><div class="version">v${_VERSION_}</div><button onclick="reloadPage()">${messages.reload}</button><script>function reloadPage(){location.reload(!0)}</script></body></html>`;
+}
+
 globalThis.addEventListener('install', () => {
 	// ev.waitUntil(globalThis.skipWaiting());
 });
@@ -28,17 +75,6 @@ globalThis.addEventListener('activate', ev => {
 	);
 });
 
-async function offlineContentHTML() {
-	const i18n = await (swLang.i18n ?? swLang.fetchLocale()) as Partial<I18n<Locale>>;
-	const messages = {
-		title: i18n.ts?._offlineScreen.title ?? 'Offline - Could not connect to server',
-		header: i18n.ts?._offlineScreen.header ?? 'Could not connect to server',
-		reload: i18n.ts?.reload ?? 'Reload',
-	};
-
-	return `<!DOCTYPE html><html lang="ja"><head><meta charset="UTF-8"><meta content="width=device-width,initial-scale=1"name="viewport"><title>${messages.title}</title><style>body{background-color:#0c1210;color:#dee7e4;font-family:Hiragino Maru Gothic Pro,BIZ UDGothic,Roboto,HelveticaNeue,Arial,sans-serif;line-height:1.35;display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:100vh;margin:0;padding:24px;box-sizing:border-box}.icon{max-width:120px;width:100%;height:auto;margin-bottom:20px;}.message{text-align:center;font-size:20px;font-weight:700;margin-bottom:20px}.version{text-align:center;font-size:90%;margin-bottom:20px}button{padding:7px 14px;min-width:100px;font-weight:700;font-family:Hiragino Maru Gothic Pro,BIZ UDGothic,Roboto,HelveticaNeue,Arial,sans-serif;line-height:1.35;border-radius:99rem;background-color:#b4e900;color:#192320;border:none;cursor:pointer;-webkit-tap-highlight-color:transparent}button:hover{background-color:#c6ff03}</style></head><body><svg class="icon"fill="none"height="24"stroke="currentColor"stroke-linecap="round"stroke-linejoin="round"stroke-width="2"viewBox="0 0 24 24"width="24"xmlns="http://www.w3.org/2000/svg"><path d="M0 0h24v24H0z"fill="none"stroke="none"/><path d="M9.58 5.548c.24 -.11 .492 -.207 .752 -.286c1.88 -.572 3.956 -.193 5.444 1c1.488 1.19 2.162 3.007 1.77 4.769h.99c1.913 0 3.464 1.56 3.464 3.486c0 .957 -.383 1.824 -1.003 2.454m-2.997 1.033h-11.343c-2.572 -.004 -4.657 -2.011 -4.657 -4.487c0 -2.475 2.085 -4.482 4.657 -4.482c.13 -.582 .37 -1.128 .7 -1.62"/><path d="M3 3l18 18"/></svg><div class="message">${messages.header}</div><div class="version">v${_VERSION_}</div><button onclick="reloadPage()">${messages.reload}</button><script>function reloadPage(){location.reload(!0)}</script></body></html>`;
-}
-
 globalThis.addEventListener('fetch', ev => {
 	let isHTMLRequest = false;
 	if (ev.request.headers.get('sec-fetch-dest') === 'document') {
@@ -50,18 +86,7 @@ globalThis.addEventListener('fetch', ev => {
 	}
 
 	if (!isHTMLRequest) return;
-	ev.respondWith(
-		fetch(ev.request)
-			.catch(async () => {
-				const html = await offlineContentHTML();
-				return new Response(html, {
-					status: 200,
-					headers: {
-						'content-type': 'text/html',
-					},
-				});
-			}),
-	);
+	ev.respondWith(respondToNavigation(ev.request));
 });
 
 globalThis.addEventListener('push', ev => {