Remote Functions Exploration PR

packages/adapter-cloudflare/test/apps/pages/package.json

@@ -13,7 +13,7 @@
 		"@sveltejs/kit": "workspace:^",
 		"@sveltejs/vite-plugin-svelte": "catalog:",
 		"server-side-dep": "file:server-side-dep",
-		"svelte": "^5.23.1",
+		"svelte": "^5.35.2",
 		"vite": "catalog:",
 		"wrangler": "^4.14.3"
 	},

packages/adapter-cloudflare/test/apps/workers/package.json

@@ -16,7 +16,7 @@
 		"@sveltejs/vite-plugin-svelte": "catalog:",
 		"cross-env": "catalog:",
 		"server-side-dep": "file:server-side-dep",
-		"svelte": "^5.23.1",
+		"svelte": "^5.35.2",
 		"vite": "catalog:",
 		"wrangler": "^4.14.3"
 	},

packages/adapter-node/index.js

@@ -46,6 +46,20 @@ export default function (opts = {}) {
 				].join('\n\n')
 			);
 
+			// TODO this is how could do caching for remote functions
+			// 			builder.copy(`${files}/cache.js`, `${tmp}/cache.js`);
+
+			// 			for (const remote of readdirSync(`${tmp}/remote`)) {
+			// 				let code = readFileSync(`${tmp}/remote/${remote}`, 'utf-8');
+			// 				// `import * as $$_self_$$` is added to remote files by our code Vite remote plugin
+			// 				code += `\n// === generated by node adapter ===
+			// import $$_add_cache from '../cache.js';
+			// for (const v of Object.values($$_self_$$)) {
+			// 	$$_add_cache(v);
+			// }\n`;
+			// 				writeFileSync(`${tmp}/remote/${remote}`, code, 'utf-8');
+			// 			}
+
 			const pkg = JSON.parse(readFileSync('package.json', 'utf8'));
 
 			// we bundle the Vite output so that deployments only need
@@ -54,7 +68,8 @@ export default function (opts = {}) {
 			const bundle = await rollup({
 				input: {
 					index: `${tmp}/index.js`,
-					manifest: `${tmp}/manifest.js`
+					manifest: `${tmp}/manifest.js`,
+					cache: `${tmp}/cache.js`
 				},
 				external: [
 					// dependencies could have deep exports, so we need a regex
@@ -80,6 +95,7 @@ export default function (opts = {}) {
 			});
 
 			builder.copy(files, out, {
+				filter: (name) => name !== 'cache.js',
 				replace: {
 					ENV: './env.js',
 					HANDLER: './handler.js',

packages/adapter-node/rollup.config.js

@@ -49,5 +49,13 @@ export default [
 			format: 'esm'
 		},
 		plugins: [nodeResolve(), commonjs(), prefixBuiltinModules()]
+	},
+	{
+		input: 'src/cache.js',
+		output: {
+			file: 'files/cache.js',
+			format: 'esm'
+		},
+		plugins: [nodeResolve(), commonjs(), prefixBuiltinModules()]
 	}
 ];

packages/adapter-node/src/cache.js

@@ -0,0 +1,87 @@
+import { dirname, join } from 'node:path';
+import { existsSync, readFileSync, rmSync, statSync, writeFileSync } from 'node:fs';
+import { fileURLToPath } from 'node:url';
+
+// This file will exist within the server folder, which is next to the prerendered folder
+const dir = join(dirname(dirname(fileURLToPath(import.meta.url))), 'prerendered');
+
+class Cache {
+	/**
+	 * @param {string} id - The unique identifier for the cache instance
+	 * @param {number | false} expiration - The expiration time in milliseconds
+	 */
+	constructor(id, expiration) {
+		this.id = id;
+		this.expiration = typeof expiration === 'number' ? expiration * 1000 : expiration;
+		this.memory_cache = new Map(); // In-memory cache to store output and write time
+	}
+
+	/** @param {string} input */
+	path(input) {
+		return join(dir, encodeURIComponent(this.id + '|' + input));
+	}
+
+	/** @param {string} input */
+	get(input) {
+		const now = Date.now();
+
+		// Check in-memory cache
+		if (this.memory_cache.has(input)) {
+			const { output, timestamp } = this.memory_cache.get(input);
+			if (this.expiration === false || now - timestamp <= this.expiration) {
+				return output;
+			} else {
+				this.delete(input);
+			}
+		}
+
+		// Check file system
+		const file_path = this.path(input);
+		if (existsSync(file_path)) {
+			const stats = statSync(file_path);
+			const last_modified = stats.mtimeMs;
+
+			if (this.expiration === false || now - last_modified <= this.expiration) {
+				const output = readFileSync(file_path, 'utf-8');
+				this.memory_cache.set(input, { output, timestamp: now });
+				return output;
+			} else {
+				this.delete(input);
+			}
+		}
+
+		return undefined;
+	}
+
+	/**
+	 * @param {string} input
+	 * @param {string} output
+	 */
+	set(input, output) {
+		const now = Date.now();
+		this.memory_cache.set(input, { output, timestamp: now });
+		writeFileSync(this.path(input), output, 'utf-8');
+
+		if (typeof this.expiration === 'number') {
+			setTimeout(() => {
+				this.delete(input);
+			}, this.expiration);
+		}
+	}
+
+	/** @param {string} input */
+	delete(input) {
+		this.memory_cache.delete(input);
+		const file_path = this.path(input);
+		if (existsSync(file_path)) {
+			rmSync(file_path);
+		}
+	}
+}
+
+/** @param {any} cache_fn */
+export default function add_cache(cache_fn) {
+	// For __ see the RemoteInfo type
+	if (cache_fn.__?.type !== 'cache') return;
+	cache_fn.cache = new Cache(cache_fn.__.id, cache_fn.__.config.expiration);
+}

packages/adapter-static/package.json

@@ -44,7 +44,7 @@
 		"@sveltejs/vite-plugin-svelte": "catalog:",
 		"@types/node": "^18.19.48",
 		"sirv": "^3.0.0",
-		"svelte": "^5.23.1",
+		"svelte": "^5.35.2",
 		"typescript": "^5.3.3",
 		"vite": "catalog:"
 	},

packages/adapter-static/test/apps/prerendered/package.json

@@ -12,7 +12,7 @@
 		"@sveltejs/kit": "workspace:^",
 		"@sveltejs/vite-plugin-svelte": "catalog:",
 		"sirv-cli": "^3.0.0",
-		"svelte": "^5.23.1",
+		"svelte": "^5.35.2",
 		"vite": "catalog:"
 	},
 	"type": "module"

packages/adapter-static/test/apps/spa/package.json

@@ -13,7 +13,7 @@
 		"@sveltejs/kit": "workspace:^",
 		"@sveltejs/vite-plugin-svelte": "catalog:",
 		"sirv-cli": "^3.0.0",
-		"svelte": "^5.23.1",
+		"svelte": "^5.35.2",
 		"vite": "catalog:"
 	},
 	"type": "module"

packages/adapter-vercel/index.js

@@ -434,6 +434,56 @@ const plugin = function (defaults = {}) {
 				}
 			}
 
+			// TODO this is how we could do it with the remote `cache` function if we want ISR
+			// if (fs.existsSync(`${builder.getServerDirectory()}/remote`)) {
+			// 	for (const remote of fs.readdirSync(`${builder.getServerDirectory()}/remote`)) {
+			// 		// For now we're not caching when a full-page-hit is responded to, and make it an ISR function for client-side hits.
+			// 		// Once Vercel data cache is available, use that instead, using a mechanism similar to the Node adapter
+			// 		const src = pathToFileURL(`${builder.getServerDirectory()}/remote/${remote}`);
+			// 		const module = await import(src.href);
+			// 		for (const value of Object.values(module)) {
+			// 			// For __ see the RemoteInfo type
+			// 			if (value.__?.type === 'cache') {
+			// 				const isr_name = value.__.id;
+			// 				const base = `${dirs.functions}/${isr_name}`;
+			// 				builder.mkdirp(base);
+
+			// 				// This is either the single function or the fallback function; both have all the remote files
+			// 				const target = `${dirs.functions}/${INTERNAL}.func`;
+			// 				const relative = path.relative(path.dirname(base), target);
+
+			// 				// create a symlink to the actual function, but use the
+			// 				// route name so that we can derive the correct URL
+			// 				fs.symlinkSync(relative, `${base}.func`);
+
+			// 				const pathname = `/${builder.getAppPath()}/remote/${value.__.id}`;
+			// 				const json = JSON.stringify(
+			// 					{
+			// 						expiration: value.__config.expiration,
+			// 						bypassToken: value.__config.bypassToken,
+			// 						allowQuery: ['__pathname', 'args'],
+			// 						passQuery: true
+			// 					},
+			// 					null,
+			// 					'\t'
+			// 				);
+
+			// 				write(`${base}.prerender-config.json`, json);
+
+			// 				static_config.routes.push({
+			// 					src: pathname + '$',
+			// 					dest: `/${isr_name}?__pathname=${pathname}`
+			// 				});
+			// 			}
+			// 		}
+
+			// 		static_config.routes.push({
+			// 			src: `/${builder.getAppPath()}/immutable/${remote}(.+)`,
+			// 			dest: `/${builder.getAppPath()}/immutable/${remote}$1`
+			// 		});
+			// 	}
+			// }
+
 			// optional chaining to support older versions that don't have this setting yet
 			if (builder.config.kit.router?.resolution === 'server') {
 				// Create a separate edge function just for server-side route resolution.

packages/enhanced-img/package.json

@@ -47,7 +47,7 @@
 		"@types/estree": "^1.0.5",
 		"@types/node": "^18.19.48",
 		"rollup": "^4.27.4",
-		"svelte": "^5.23.1",
+		"svelte": "^5.35.2",
 		"typescript": "^5.6.3",
 		"vite": "catalog:",
 		"vitest": "catalog:"

packages/enhanced-img/src/vite-plugin.js

@@ -263,7 +263,7 @@ function get_attr_value(node, attr) {
 
 /**
  * @param {string} content
- * @param {import('../types/internal.js').Attribute[]} attributes
+ * @param {import('svelte/compiler').AST.RegularElement['attributes']} attributes
  * @param {{
  *   src: string,
  *   width: string | number,
@@ -324,7 +324,7 @@ function stringToNumber(param) {
  * @param {import('vite-imagetools').Picture} image
  */
 function img_to_picture(content, node, image) {
-	/** @type {import('../types/internal.js').Attribute[]} attributes */
+	/** @type {import('svelte/compiler').AST.RegularElement['attributes']} */
 	const attributes = node.attributes;
 	const index = attributes.findIndex(
 		(attribute) => 'name' in attribute && attribute.name === 'sizes'

packages/kit/package.json

@@ -18,6 +18,7 @@
 	"homepage": "https://svelte.dev",
 	"type": "module",
 	"dependencies": {
+		"@standard-schema/spec": "^1.0.0",
 		"@sveltejs/acorn-typescript": "^1.0.5",
 		"@types/cookie": "^0.6.0",
 		"acorn": "^8.14.1",
@@ -37,9 +38,9 @@
 		"@types/connect": "^3.4.38",
 		"@types/node": "^18.19.48",
 		"@types/set-cookie-parser": "^2.4.7",
-		"dts-buddy": "^0.6.1",
+		"dts-buddy": "^0.6.2",
 		"rollup": "^4.14.2",
-		"svelte": "^5.23.1",
+		"svelte": "^5.35.2",
 		"svelte-preprocess": "^6.0.0",
 		"typescript": "^5.3.3",
 		"vite": "catalog:",

packages/kit/src/core/config/index.spec.js

@@ -76,6 +76,9 @@ const get_defaults = (prefix = '') => ({
 			publicPrefix: 'PUBLIC_',
 			privatePrefix: ''
 		},
+		experimental: {
+			remoteFunctions: false
+		},
 		files: {
 			assets: join(prefix, 'static'),
 			hooks: {

packages/kit/src/core/config/options.js

@@ -120,6 +120,10 @@ const options = object(
 				privatePrefix: string('')
 			}),
 
+			experimental: object({
+				remoteFunctions: boolean(false)
+			}),
+
 			files: object({
 				assets: string('static'),
 				hooks: object({

packages/kit/src/core/generate_manifest/index.js

@@ -8,6 +8,7 @@ import { compact } from '../../utils/array.js';
 import { join_relative } from '../../utils/filesystem.js';
 import { dedent } from '../sync/utils.js';
 import { find_server_assets } from './find_server_assets.js';
+import { hash } from '../../runtime/hash.js'; // TODO move this function
 import { uneval } from 'devalue';
 
 /**
@@ -100,6 +101,9 @@ export function generate_manifest({ build_data, prerendered, relative_path, rout
 				nodes: [
 					${(node_paths).map(loader).join(',\n')}
 				],
+				remotes: {
+					${build_data.manifest_data.remotes.map((filename) => `'${hash(filename)}': ${loader(join_relative(relative_path, resolve_symlinks(build_data.server_manifest, filename).chunk.file))}`).join(',\n\t\t\t\t\t')}
+				},
 				routes: [
 					${routes.map(route => {
 						if (!route.page && !route.endpoint) return;

packages/kit/src/core/postbuild/analyse.js

@@ -82,7 +82,8 @@ async function analyse({
 	/** @type {import('types').ServerMetadata} */
 	const metadata = {
 		nodes: [],
-		routes: new Map()
+		routes: new Map(),
+		remotes: new Map()
 	};
 
 	const nodes = await Promise.all(manifest._.nodes.map((loader) => loader()));
@@ -164,6 +165,18 @@ async function analyse({
 		});
 	}
 
+	// analyse remotes
+	for (const remote of Object.keys(manifest._.remotes)) {
+		const modules = await manifest._.remotes[remote]();
+		const exports = new Map();
+		for (const [name, value] of Object.entries(modules)) {
+			const type = /** @type {import('types').RemoteInfo} */ (value.__)?.type;
+			if (!type) continue;
+			exports.set(type, (exports.get(type) ?? []).concat(name));
+		}
+		metadata.remotes.set(remote, exports);
+	}
+
 	return { metadata, static_exports };
 }
 

packages/kit/src/core/postbuild/fallback.js

@@ -41,7 +41,8 @@ async function generate_fallback({ manifest_path, env }) {
 		},
 		prerendering: {
 			fallback: true,
-			dependencies: new Map()
+			dependencies: new Map(),
+			remote_responses: new Map()
 		},
 		read: (file) => readFileSync(join(config.files.assets, file))
 	});