Files
Maurice c9dfe9c688 fix(pwa): recover from a dead chunk and a broken precache after an update (#2524)
After an update, a tab or a device whose service worker still serves the
previous build asks for chunks the update removed. The server answered those
requests with index.html and a 200, so the import failed with a MIME error,
and everything caching in between was free to keep the HTML as the chunk. A
precache install that met a missing file stored it, and Workbox reuses hashed
entries by URL, so the device showed "A new version is available" on every
load, whatever the reload or the cleared browser cache, and carried the broken
entry into every later release that keeps the file's name.

The SPA fallback now answers a GET for a build file that is not on disk with
a plain 404 (no-store) instead of index.html. A precache install refuses it,
so the worker whose cache is complete stays in charge until the new build is.
index.html is sent relative to the public dir, which also stops an install
living under a dot directory from answering every deep link with a 404.

On the client, the reload after a dead chunk (the automatic one and the
button on the update screen) no longer goes straight back to the worker that
served the broken shell. When that same worker is still in charge and the
server answers, its precache and registration are dropped first, so the
reload reaches the build the server runs now. Offline, and in offline mode,
the shell is kept. Every recovery reload, and the reload of the version
handover, asks for the page under a one-off query parameter, so a proxy or
CDN that keeps index.html against its headers cannot hand back the stale
shell either.

A chunk the entry imports statically fails before any of that code runs.
shell-guard.js, a small classic script loaded ahead of the entry, watches for
exactly that failure and runs the same recovery, once per session.

A stylesheet, font or icon that holds a page raises no error at all, so once
the app has started and the browser is idle, it looks through the precache
for entries that hold a page under a build file's name, fetches each from
the server past every cache and puts it back in place. A repaired stylesheet
is loaded again, and so are the app's stylesheets when a font was repaired,
since the browser does not try a face that failed again in the same
document. Only the headers are read, a precache found sound is not looked at
again until its entries change, nothing is fetched while nothing is broken,
and nothing happens offline, in offline mode or without storage. An answer
that is not the file (an auth wall, its login page, a server error) leaves
the entry for the next launch.

A page the recovery loaded from the network already runs the version the
server reports, so the version handover now records it instead of reloading
it a second time once the new worker takes over. A page loaded past an older
worker that is still in charge, as a hard reload does, still asks for the new
worker and records the version only once that has taken over, so the next
tab or launch cannot get the old shell without a handover.

Dropping the worker ends a Web Push subscription with it, so on such a device
the settings card shows push as off until it is switched on again. A missing
sw-push.js now fails the worker install with a 404 rather than index.html; the
comments that described the old answer say so.
2026-09-26 10:36:02 +02:00

298 lines
13 KiB
TypeScript

// FE-SW-PUSH-001 to FE-SW-PUSH-016: the Web Push handlers in public/sw-push.js.
//
// The file is a classic script that Workbox imports into the generated service
// worker, so it sits outside src/, ESLint and coverage. This spec is its only
// guard: it evaluates the real file against a fake worker global and drives
// the three events the way a browser would.
//
// What matters most:
// - every push shows a notification inside waitUntil, whatever arrives, since
// Chrome demands one per push and WebKit revokes a subscription that stays
// silent;
// - a click only ever opens a path on this origin;
// - a renewed subscription reaches the server, and the old one is forgotten
// only once the new one is stored.
// Plus the drift guard: vite.config.js must import the file, and it must exist,
// or importScripts gets a 404 instead of a script and the new worker never
// installs.
import { describe, it, expect, vi, afterEach } from 'vitest';
import { existsSync, readFileSync } from 'node:fs';
import { resolve } from 'node:path';
const ORIGIN = 'https://trek.example';
const SOURCE_PATH = resolve(process.cwd(), 'public/sw-push.js');
const SOURCE = readFileSync(SOURCE_PATH, 'utf8');
type Listener = (event: Record<string, unknown>) => void;
interface FakeWindow {
url: string;
focused: boolean;
focus: ReturnType<typeof vi.fn>;
navigate: ReturnType<typeof vi.fn>;
}
function fakeWindow(over: Partial<FakeWindow> = {}): FakeWindow {
const win: FakeWindow = {
url: `${ORIGIN}/dashboard`,
focused: false,
focus: vi.fn(async () => win),
navigate: vi.fn(async () => win),
...over,
};
return win;
}
function boot(windows: FakeWindow[] = []) {
const listeners: Record<string, Listener> = {};
const registration = {
showNotification: vi.fn(async (_title: string, _options: NotificationOptions) => undefined),
pushManager: { subscribe: vi.fn() },
};
const clients = {
matchAll: vi.fn(async () => windows),
openWindow: vi.fn(async (_url: string) => null),
};
const self = {
addEventListener: (type: string, fn: Listener) => {
listeners[type] = fn;
},
registration,
clients,
location: { origin: ORIGIN },
};
const fetchMock = vi.fn(async (_url: string, _init?: RequestInit) => new Response(null, { status: 200 }));
new Function('self', 'fetch', SOURCE)(self, fetchMock);
return { listeners, registration, clients, fetch: fetchMock };
}
/** Dispatches one event and hands back what it passed to waitUntil. */
function fire(listener: Listener, event: Record<string, unknown>): Promise<unknown> {
let waited: Promise<unknown> | undefined;
listener({ ...event, waitUntil: (p: Promise<unknown>) => { waited = p; } });
expect(waited).toBeInstanceOf(Promise);
return waited as Promise<unknown>;
}
function pushData(value: unknown) {
return {
json: () => (typeof value === 'string' ? JSON.parse(value) : value),
text: () => (typeof value === 'string' ? value : JSON.stringify(value)),
};
}
afterEach(() => {
vi.restoreAllMocks();
});
describe('sw-push.js: push', () => {
it('FE-SW-PUSH-001: shows the payload as sent, with the icon and the path to open', async () => {
const sw = boot();
await fire(sw.listeners.push, {
data: pushData({ title: 'Trip invite', body: 'Anna invited you to Rome', url: '/trips/5' }),
});
expect(sw.registration.showNotification).toHaveBeenCalledWith('Trip invite', {
body: 'Anna invited you to Rome',
icon: '/icons/icon-192x192.png',
data: { url: '/trips/5' },
});
});
it('FE-SW-PUSH-001b: a tagged push replaces the last one with that tag and still alerts', async () => {
const sw = boot();
const message = { title: 'New message in "Rome"', body: 'anna: see you there', url: '/trips/5' };
await fire(sw.listeners.push, { data: pushData({ ...message, tag: 'collab_message:/trips/5' }) });
expect(sw.registration.showNotification).toHaveBeenCalledWith(message.title, {
body: message.body,
icon: '/icons/icon-192x192.png',
tag: 'collab_message:/trips/5',
renotify: true,
data: { url: '/trips/5' },
});
// Without a tag there is nothing to replace, and renotify would be refused.
await fire(sw.listeners.push, { data: pushData({ ...message, tag: '' }) });
expect(sw.registration.showNotification.mock.calls[1][1]).not.toHaveProperty('tag');
expect(sw.registration.showNotification.mock.calls[1][1]).not.toHaveProperty('renotify');
});
it('FE-SW-PUSH-001c: renotify follows the tag alone, never the payload', async () => {
const sw = boot();
// showNotification throws on renotify without a tag, so a payload asking for it must not get it.
await fire(sw.listeners.push, { data: pushData({ title: 'Booking', body: 'changed', renotify: true }) });
expect(sw.registration.showNotification.mock.calls[0][1]).not.toHaveProperty('renotify');
// Any tag at all brings it, not only the chat one.
await fire(sw.listeners.push, { data: pushData({ title: 'Booking', body: 'changed', tag: 'any' }) });
expect(sw.registration.showNotification.mock.calls[1][1]).toMatchObject({ tag: 'any', renotify: true });
});
it('FE-SW-PUSH-002: a payload that is not JSON still shows, with its text as the body', async () => {
const sw = boot();
await fire(sw.listeners.push, { data: pushData('plain words, no JSON') });
expect(sw.registration.showNotification).toHaveBeenCalledWith('TREK', {
body: 'plain words, no JSON',
icon: '/icons/icon-192x192.png',
data: { url: '/' },
});
});
it('FE-SW-PUSH-003: a push without data, or with the wrong types, still shows something', async () => {
const sw = boot();
await fire(sw.listeners.push, { data: null });
await fire(sw.listeners.push, { data: pushData({ title: 42, body: ['x'], tag: 7 }) });
await fire(sw.listeners.push, { data: pushData('"just a string"') });
for (const call of sw.registration.showNotification.mock.calls) {
expect(call[0]).toBe('TREK');
expect(call[1]).toEqual({ body: '', icon: '/icons/icon-192x192.png', data: { url: '/' } });
}
expect(sw.registration.showNotification).toHaveBeenCalledTimes(3);
});
it('FE-SW-PUSH-004: a url pointing anywhere else is replaced by the start page', async () => {
const sw = boot();
for (const url of ['https://evil.example/phish', '//evil.example/x', 'javascript:alert(1)']) {
await fire(sw.listeners.push, { data: pushData({ title: 'x', body: 'y', url }) });
}
for (const call of sw.registration.showNotification.mock.calls) {
expect(call[1].data.url).toBe('/');
}
});
it('FE-SW-PUSH-005: a same-origin absolute url is reduced to its path, query and hash', async () => {
const sw = boot();
await fire(sw.listeners.push, { data: pushData({ title: 'x', body: 'y', url: `${ORIGIN}/trips/5?tab=plan#day-2` }) });
expect(sw.registration.showNotification.mock.calls[0][1]).toMatchObject({ data: { url: '/trips/5?tab=plan#day-2' } });
});
});
describe('sw-push.js: notificationclick', () => {
function click(sw: ReturnType<typeof boot>, url: unknown) {
const notification = { close: vi.fn(), data: { url } };
return { notification, done: fire(sw.listeners.notificationclick, { notification }) };
}
it('FE-SW-PUSH-006: closes the notification, focuses a TREK window and takes it there', async () => {
const win = fakeWindow();
const sw = boot([win]);
const { notification, done } = click(sw, '/trips/5');
await done;
expect(notification.close).toHaveBeenCalled();
expect(sw.clients.matchAll).toHaveBeenCalledWith({ type: 'window', includeUncontrolled: true });
expect(win.focus).toHaveBeenCalled();
expect(win.navigate).toHaveBeenCalledWith(`${ORIGIN}/trips/5`);
expect(sw.clients.openWindow).not.toHaveBeenCalled();
});
it('FE-SW-PUSH-007: prefers the window that already has the focus', async () => {
const background = fakeWindow();
const focused = fakeWindow({ focused: true });
const sw = boot([background, focused]);
await click(sw, '/notifications').done;
expect(focused.navigate).toHaveBeenCalledWith(`${ORIGIN}/notifications`);
expect(background.focus).not.toHaveBeenCalled();
});
it('FE-SW-PUSH-008: opens a window when none is left', async () => {
const sw = boot([]);
await click(sw, '/trips/5').done;
expect(sw.clients.openWindow).toHaveBeenCalledWith(`${ORIGIN}/trips/5`);
});
it('FE-SW-PUSH-009: a window the worker may not navigate gets a new one instead', async () => {
const uncontrolled = fakeWindow();
uncontrolled.navigate.mockRejectedValueOnce(new TypeError('not controlled'));
const sw = boot([uncontrolled]);
await click(sw, '/trips/5').done;
expect(sw.clients.openWindow).toHaveBeenCalledWith(`${ORIGIN}/trips/5`);
});
it('FE-SW-PUSH-010: a url from elsewhere, or none at all, opens the start page', async () => {
const sw = boot([]);
await click(sw, 'https://evil.example/').done;
const notification = { close: vi.fn(), data: null };
await fire(sw.listeners.notificationclick, { notification });
expect(sw.clients.openWindow.mock.calls).toEqual([[`${ORIGIN}/`], [`${ORIGIN}/`]]);
});
});
describe('sw-push.js: pushsubscriptionchange', () => {
const OLD_KEY = new Uint8Array([4, 1, 2, 3]).buffer;
function renewed(endpoint: string) {
return { endpoint, toJSON: () => ({ endpoint, keys: { p256dh: 'p', auth: 'a' } }) };
}
it('FE-SW-PUSH-011: subscribes again with the old key, stores the new one, then forgets the old', async () => {
const sw = boot();
sw.registration.pushManager.subscribe.mockResolvedValue(renewed('https://push.example/new'));
await fire(sw.listeners.pushsubscriptionchange, {
oldSubscription: { endpoint: 'https://push.example/old', options: { applicationServerKey: OLD_KEY } },
newSubscription: null,
});
expect(sw.registration.pushManager.subscribe).toHaveBeenCalledWith({ userVisibleOnly: true, applicationServerKey: OLD_KEY });
expect(sw.fetch).toHaveBeenCalledTimes(2);
const [postUrl, post] = sw.fetch.mock.calls[0];
expect(postUrl).toBe('/api/notifications/push/subscriptions');
expect(post).toMatchObject({ method: 'POST', credentials: 'same-origin' });
expect(JSON.parse(String(post?.body))).toEqual({
subscription: { endpoint: 'https://push.example/new', keys: { p256dh: 'p', auth: 'a' } },
});
const [, del] = sw.fetch.mock.calls[1];
expect(del).toMatchObject({ method: 'DELETE', credentials: 'same-origin' });
expect(JSON.parse(String(del?.body))).toEqual({ endpoint: 'https://push.example/old' });
});
it('FE-SW-PUSH-012: uses a subscription the browser already made', async () => {
const sw = boot();
await fire(sw.listeners.pushsubscriptionchange, {
oldSubscription: null,
newSubscription: renewed('https://push.example/fresh'),
});
expect(sw.registration.pushManager.subscribe).not.toHaveBeenCalled();
expect(sw.fetch).toHaveBeenCalledTimes(1);
});
it('FE-SW-PUSH-013: keeps the row when the endpoint did not change', async () => {
const sw = boot();
await fire(sw.listeners.pushsubscriptionchange, {
oldSubscription: { endpoint: 'https://push.example/same', options: { applicationServerKey: OLD_KEY } },
newSubscription: renewed('https://push.example/same'),
});
expect(sw.fetch).toHaveBeenCalledTimes(1);
});
it('FE-SW-PUSH-014: forgets nothing when the server did not take the new subscription', async () => {
const sw = boot();
sw.fetch.mockResolvedValueOnce(new Response(null, { status: 401 }));
await fire(sw.listeners.pushsubscriptionchange, {
oldSubscription: { endpoint: 'https://push.example/old', options: { applicationServerKey: OLD_KEY } },
newSubscription: renewed('https://push.example/new'),
});
expect(sw.fetch).toHaveBeenCalledTimes(1);
});
it('FE-SW-PUSH-015: gives up quietly, never with a rejected waitUntil', async () => {
const warn = vi.spyOn(console, 'warn').mockImplementation(() => {});
const sw = boot();
sw.registration.pushManager.subscribe.mockRejectedValueOnce(new Error('push service down'));
await expect(
fire(sw.listeners.pushsubscriptionchange, {
oldSubscription: { endpoint: 'https://push.example/old', options: { applicationServerKey: OLD_KEY } },
newSubscription: null,
}),
).resolves.toBeUndefined();
expect(warn).toHaveBeenCalled();
await fire(sw.listeners.pushsubscriptionchange, { oldSubscription: null, newSubscription: null });
expect(sw.fetch).not.toHaveBeenCalled();
});
});
describe('sw-push.js is wired into the service worker (drift guard)', () => {
it('FE-SW-PUSH-016: vite.config.js imports it and public/ ships it', () => {
const config = readFileSync(resolve(process.cwd(), 'vite.config.js'), 'utf8');
expect(config).toMatch(/importScripts:\s*\[\s*'sw-push\.js'\s*\]/);
expect(existsSync(SOURCE_PATH)).toBe(true);
});
});