fix(Service Worker): Refactor and clean up the cache logic in the Service Worker to improve maintainability and handle Safari-specific cache behavior.

This commit is contained in:
Philipp Kunz 2025-02-04 01:52:48 +01:00
parent 6cedd53d61
commit 270230b0ca
3 changed files with 151 additions and 126 deletions

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@ -1,5 +1,13 @@
# Changelog
## 2025-02-04 - 3.0.62 - fix(Service Worker)
Refactor and clean up the cache logic in the Service Worker to improve maintainability and handle Safari-specific cache behavior.
- Refactored logic for determining cached domains, enhancing the readability and maintainability of the code.
- Improved handling of CORS settings in caching requests, notably bypassing caching for soft cached domains in Safari to avoid CORS issues.
- Enhanced error response creation for failed resource fetching, maintaining clarity on why and how certain resources were not fetched or cached.
- Revised the structure of the caching logic to ensure consistent behavior across all supported browsers.
## 2025-02-04 - 3.0.61 - fix(ServiceWorkerCacheManager)
Fixed caching mechanism to better support Safari's handling of soft-cached domains.

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@ -3,6 +3,6 @@
*/
export const commitinfo = {
name: '@api.global/typedserver',
version: '3.0.61',
version: '3.0.62',
description: 'A TypeScript-based project for easy serving of static files with support for live reloading, compression, and typed requests.'
}

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@ -11,14 +11,14 @@ export class CacheManager {
};
/**
* Hard cached domains are always attempted to be cached, regardless of browser.
* Hard cached domains are always attempted to be cached.
* For example, your internal origin, fonts, CDNs, etc.
*/
public hardCachedDomains: string[];
/**
* Soft cached domains will be cached normally except on Safari.
* This is useful for domains where Safaris handling of cached CORS responses is problematic.
* Soft cached domains will be cached normally on nonSafari browsers,
* but on Safari caching is bypassed to avoid CORS issues.
*/
public softCachedDomains: string[];
@ -42,87 +42,90 @@ export class CacheManager {
}
/**
* Returns true if the given URL is in one of the hard cached domains.
* Returns true if the given URL matches a hard cached domain.
*/
private isHardCached(url: string): boolean {
return this.hardCachedDomains.some(domain => url.includes(domain));
}
/**
* Returns true if the given URL is in one of the soft cached domains.
* Returns true if the given URL matches a soft cached domain.
*/
private isSoftCached(url: string): boolean {
return this.softCachedDomains.some(domain => url.includes(domain));
}
/**
* Returns true if the given URL is cacheable (i.e. belongs to either hard or soft domains).
* Returns true if the given URL should be cached (hard or soft).
*/
private isCacheable(url: string): boolean {
return this.isHardCached(url) || this.isSoftCached(url);
}
/**
* Creates a new Request with appropriate CORS settings.
*/
private createMatchRequest(requestArg: Request): Request {
let matchRequest: Request;
// For internal requests, use the original request.
if (requestArg.url.startsWith(this.losslessServiceWorkerRef.serviceWindowRef.location.origin)) {
matchRequest = requestArg;
} else {
// For external requests, choose the request mode based on whether the URL is soft-cached.
const isSoft = this.isSoftCached(requestArg.url);
// For soft cached domains we use 'no-cors' to avoid CORS errors (at the expense of an opaque response).
const mode: RequestMode = isSoft ? 'no-cors' : 'cors';
matchRequest = new Request(requestArg.url, {
method: requestArg.method,
headers: requestArg.headers,
mode,
credentials: 'same-origin',
redirect: 'follow'
});
}
return matchRequest;
}
/**
* Creates a 500 error response.
*/
private async create500Response(requestArg: Request, responseArg: Response): Promise<Response> {
return new Response(
`
<html>
<head>
<style>
.note {
padding: 10px;
color: #fff;
background: #000;
border-bottom: 1px solid #e4002b;
margin-bottom: 20px;
}
</style>
</head>
<body>
<div class="note">
<strong>Service worker running, but status 500</strong><br>
</div>
Service worker is unable to fetch this request.<br>
Request URL: ${requestArg.url}<br>
Response Type: ${responseArg.type}<br>
Response Body: ${await responseArg.clone().text()}<br>
</body>
</html>
`,
{
headers: { "Content-Type": "text/html" },
status: 500
}
);
}
/**
* Sets up the fetch event listener and caching logic.
*/
private _setupCache = () => {
const createMatchRequest = (requestArg: Request): Request => {
let matchRequest: Request;
// For internal requests, use the original request.
if (requestArg.url.startsWith(this.losslessServiceWorkerRef.serviceWindowRef.location.origin)) {
matchRequest = requestArg;
} else {
// For external requests, create a new Request with appropriate CORS settings.
// For soft cached domains, we use 'no-cors' to keep the response opaque.
const isSoft = this.isSoftCached(requestArg.url);
const mode: RequestMode = isSoft ? 'no-cors' : 'cors';
matchRequest = new Request(requestArg.url, {
method: requestArg.method,
headers: requestArg.headers,
mode,
credentials: 'same-origin',
redirect: 'follow'
});
}
return matchRequest;
};
/**
* Creates a 500 error response.
*/
const create500Response = async (requestArg: Request, responseArg: Response): Promise<Response> => {
return new Response(
`
<html>
<head>
<style>
.note {
padding: 10px;
color: #fff;
background: #000;
border-bottom: 1px solid #e4002b;
margin-bottom: 20px;
}
</style>
</head>
<body>
<div class="note">
<strong>Service worker running, but status 500</strong><br>
</div>
Service worker is unable to fetch this request.<br>
Request URL: ${requestArg.url}<br>
Response Type: ${responseArg.type}<br>
Response Body: ${await responseArg.clone().text()}<br>
</body>
</html>
`,
{
headers: { "Content-Type": "text/html" },
status: 500
}
);
};
this.losslessServiceWorkerRef.serviceWindowRef.addEventListener('fetch', async (fetchEventArg: any) => {
const originalRequest: Request = fetchEventArg.request;
const parsedUrl = new URL(originalRequest.url);
@ -143,24 +146,24 @@ export class CacheManager {
const done = plugins.smartpromise.defer<Response>();
fetchEventArg.respondWith(done.promise);
// Determine if the request should be cached.
// Only handle GET requests for caching.
if (originalRequest.method === 'GET' && this.isCacheable(originalRequest.url)) {
// Check if running on Safari.
// Determine if the browser is Safari.
const userAgent = (self.navigator && self.navigator.userAgent) || "";
const isSafari = /Safari/.test(userAgent) && !/Chrome/.test(userAgent);
// For soft cached domains on Safari, bypass caching.
// For soft cached domains on Safari, bypass caching entirely.
if (this.isSoftCached(originalRequest.url) && isSafari) {
logger.log('info', `Safari detected bypass caching for soft cached domain: ${originalRequest.url}`);
const networkResponse = await fetch(originalRequest).catch(async err => {
return await create500Response(originalRequest, new Response(err.message));
return await this.create500Response(originalRequest, new Response(err.message));
});
done.resolve(networkResponse);
return;
}
// For other cases, try serving from cache.
const matchRequest = createMatchRequest(originalRequest);
// Try to serve from cache.
const matchRequest = this.createMatchRequest(originalRequest);
const cachedResponse = await caches.match(matchRequest);
if (cachedResponse) {
logger.log('ok', `CACHED: found cached response for ${matchRequest.url}`);
@ -170,68 +173,82 @@ export class CacheManager {
logger.log('info', `NOTYETCACHED: fetching and caching ${matchRequest.url}`);
const newResponse: Response = await fetch(matchRequest).catch(async err => {
return await create500Response(matchRequest, new Response(err.message));
return await this.create500Response(matchRequest, new Response(err.message));
});
// Do not cache responses that are not successful or are opaque (when not expected).
if (newResponse.status > 299 || newResponse.type === 'opaque') {
logger.log(
'error',
`NOTCACHED: cannot cache response for ${matchRequest.url} (status: ${newResponse.status}, type: ${newResponse.type})`
);
done.resolve(await create500Response(matchRequest, newResponse));
// If the response status indicates an error, don't cache.
if (newResponse.status > 299) {
logger.log('error', `NOTCACHED: response for ${matchRequest.url} has status ${newResponse.status}`);
done.resolve(await this.create500Response(matchRequest, newResponse));
return;
} else {
// Open the runtime cache.
const cache = await caches.open(this.usedCacheNames.runtimeCacheName);
const responseToCache = newResponse.clone();
// Build new headers preserving all except caching-related headers.
const headers = new Headers();
responseToCache.headers.forEach((value, key) => {
if (!['Cache-Control', 'cache-control', 'Expires', 'expires', 'Pragma', 'pragma'].includes(key)) {
headers.set(key, value);
}
});
// Ensure necessary CORS headers are present.
if (!headers.has('Access-Control-Allow-Origin')) {
headers.set('Access-Control-Allow-Origin', '*');
}
if (!headers.has('Access-Control-Allow-Methods')) {
headers.set('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE, OPTIONS');
}
if (!headers.has('Access-Control-Allow-Headers')) {
headers.set('Access-Control-Allow-Headers', 'Content-Type');
}
// Set caching headers to prevent browser caching.
headers.set('Cache-Control', 'no-store, no-cache, must-revalidate, proxy-revalidate');
headers.set('Pragma', 'no-cache');
headers.set('Expires', '0');
headers.set('Surrogate-Control', 'no-store');
// Read the response body as a blob (helps prevent issues with locked streams on Safari).
let newCachedResponse: Response;
try {
const bodyBlob = await responseToCache.blob();
newCachedResponse = new Response(bodyBlob, {
status: responseToCache.status,
statusText: responseToCache.statusText,
headers
});
} catch (err) {
newCachedResponse = newResponse;
}
await cache.put(matchRequest, newCachedResponse);
logger.log('ok', `NOWCACHED: response for ${matchRequest.url} cached successfully`);
done.resolve(newResponse);
}
// Handle opaque responses separately.
if (newResponse.type === 'opaque') {
// For soft-cached domains we expect opaque responses (from no-cors fetches).
if (this.isSoftCached(matchRequest.url)) {
const cache = await caches.open(this.usedCacheNames.runtimeCacheName);
// Cache the opaque response as-is.
await cache.put(matchRequest, newResponse.clone());
logger.log('ok', `NOWCACHED: cached opaque response for ${matchRequest.url}`);
done.resolve(newResponse);
return;
} else {
// If an opaque response comes from a non-soft domain, treat it as an error.
logger.log('error', `NOTCACHED: opaque response received for non-soft domain ${matchRequest.url}`);
done.resolve(await this.create500Response(matchRequest, newResponse));
return;
}
}
// For non-opaque responses, adjust headers and cache.
const cache = await caches.open(this.usedCacheNames.runtimeCacheName);
const responseToCache = newResponse.clone();
const headers = new Headers();
responseToCache.headers.forEach((value, key) => {
// Preserve all headers except caching-related ones.
if (!['Cache-Control', 'cache-control', 'Expires', 'expires', 'Pragma', 'pragma'].includes(key)) {
headers.set(key, value);
}
});
// Ensure necessary CORS headers.
if (!headers.has('Access-Control-Allow-Origin')) {
headers.set('Access-Control-Allow-Origin', '*');
}
if (!headers.has('Access-Control-Allow-Methods')) {
headers.set('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE, OPTIONS');
}
if (!headers.has('Access-Control-Allow-Headers')) {
headers.set('Access-Control-Allow-Headers', 'Content-Type');
}
// Prevent browser caching while allowing service worker caching.
headers.set('Cache-Control', 'no-store, no-cache, must-revalidate, proxy-revalidate');
headers.set('Pragma', 'no-cache');
headers.set('Expires', '0');
headers.set('Surrogate-Control', 'no-store');
// Read the response body as a blob so we can create a new Response with modified headers.
let newCachedResponse: Response;
try {
const bodyBlob = await responseToCache.blob();
newCachedResponse = new Response(bodyBlob, {
status: responseToCache.status,
statusText: responseToCache.statusText,
headers
});
} catch (err) {
newCachedResponse = newResponse;
}
await cache.put(matchRequest, newCachedResponse);
logger.log('ok', `NOWCACHED: cached response for ${matchRequest.url}`);
done.resolve(newResponse);
} else {
// For non-cacheable requests, fetch directly from the network.
logger.log('ok', `NOTCACHED: fetching ${originalRequest.url} from origin (non-cacheable)`);
const networkResponse = await fetch(originalRequest).catch(async err => {
return await create500Response(originalRequest, new Response(err.message));
return await this.create500Response(originalRequest, new Response(err.message));
});
done.resolve(networkResponse);
}
@ -240,7 +257,7 @@ export class CacheManager {
/**
* Cleans all caches.
* Should only be run when a new service worker is activated.
* Should be run when a new service worker is activated.
* @param reasonArg A reason for the cache cleanup.
*/
public cleanCaches = async (reasonArg = 'no reason given'): Promise<void> => {
@ -272,4 +289,4 @@ export class CacheManager {
}
}
}
}
}