[feat] Add configurable cache to worker responses

packages/adapter-cloudflare-workers/README.md

@@ -22,6 +22,13 @@ bucket = "./build"
 entry-point = "./workers-site"
 ```
 
+The adapter accepts the following configuration properties:
+| property | default | description |
+|---|---|---|
+| `pageCacheTTL` | `null` | Sets `cache-control` `max-age` for rendered responses if not defined. WARNING: this will apply to all page/request routes, disabled by default for security reasons. |
+| `staticCacheTTL` | `60 * 60 * 24 * 90` (90 days) | Sets `cache-control` `max-age` for static assets. |
+| `edgeCacheTTL` | `60 * 60 * 24 * 90` (90 days) | Sets CloudFlare Edge Cache TTL for static assets. |
+
 It's recommended that you add the `build` and `workers-site` folders (or whichever other folders you specify) to your `.gitignore`.
 
 More info on configuring a cloudflare worker site can be found [here](https://developers.cloudflare.com/workers/platform/sites/start-from-existing)

packages/adapter-cloudflare-workers/files/entry.js

@@ -7,12 +7,28 @@ addEventListener('fetch', (event) => {
 });
 
 async function handle(event) {
+	// fall back to an app route
+	const request = event.request;
+	const request_url = new URL(request.url);
+
 	// try static files first
-	if (event.request.method == 'GET') {
+	if (event.request.method == 'GET' && /\/.+\..+$/.test(request_url.pathname)) {
 		try {
+			// TODO add per-asset/page options for cache
+			// use defaults for bot files (2d edge cache)
+			if (/sitemap.*\.xml$|robots.txt$/.test(request_url.pathname)) {
+				return await getAssetFromKV(event);
+			}
 			// TODO rather than attempting to get an asset,
 			// use the asset manifest to see if it exists
-			return await getAssetFromKV(event);
+			return await getAssetFromKV(event, {
+				cacheControl: {
+					// eslint-disable-next-line no-undef
+					browserTTL: STATIC_CACHE_TTL,
+					// eslint-disable-next-line no-undef
+					edgeTTL: EDGE_CACHE_TTL
+				}
+			});
 		} catch (e) {
 			if (!(e instanceof NotFoundError)) {
 				return new Response('Error loading static asset:' + (e.message || e.toString()), {
@@ -22,10 +38,6 @@ async function handle(event) {
 		}
 	}
 
-	// fall back to an app route
-	const request = event.request;
-	const request_url = new URL(request.url);
-
 	try {
 		const rendered = await render({
 			host: request_url.host,
@@ -37,6 +49,13 @@ async function handle(event) {
 		});
 
 		if (rendered) {
+			const { headers } = rendered;
+			// inject cache-control header
+			// eslint-disable-next-line no-undef
+			if (!!PAGE_CACHE_TTL && !(headers['Cache-Control'] || headers['cache-control'])) {
+				// eslint-disable-next-line no-undef
+				rendered.headers['cache-control'] = `max-age=${PAGE_CACHE_TTL}`;
+			}
 			return new Response(rendered.body, {
 				status: rendered.status,
 				headers: rendered.headers

packages/adapter-cloudflare-workers/index.js

@@ -4,7 +4,7 @@ import esbuild from 'esbuild';
 import toml from '@iarna/toml';
 import { fileURLToPath } from 'url';
 
-export default function () {
+export default function (options = {}) {
 	/** @type {import('@sveltejs/kit').Adapter} */
 	const adapter = {
 		name: '@sveltejs/adapter-cloudflare-workers',
@@ -29,12 +29,22 @@ export default function () {
 			utils.log.minor('Generating worker...');
 			utils.copy(`${files}/entry.js`, '.svelte-kit/cloudflare-workers/entry.js');
 
+			const {
+				pageCacheTTL = null,
+				staticCacheTTL = 60 * 60 * 24 * 90, // 90 days
+				edgeCacheTTL = 60 * 60 * 24 * 90 // 90 days
+			} = options;
 			await esbuild.build({
 				entryPoints: ['.svelte-kit/cloudflare-workers/entry.js'],
 				outfile: `${entrypoint}/index.js`,
 				bundle: true,
 				target: 'es2020',
-				platform: 'node' // TODO would be great if we could generate ESM and use type = "javascript"
+				platform: 'node', // TODO would be great if we could generate ESM and use type = "javascript"
+				define: {
+					PAGE_CACHE_TTL: pageCacheTTL,
+					STATIC_CACHE_TTL: staticCacheTTL,
+					EDGE_CACHE_TTL: edgeCacheTTL
+				}
 			});
 
 			fs.writeFileSync(`${entrypoint}/package.json`, JSON.stringify({ main: 'index.js' }));