chore: first implementation for serialized config

packages/astro/client.d.ts

@@ -189,6 +189,18 @@ declare module 'astro:middleware' {
 	export * from 'astro/virtual-modules/middleware.js';
 }
 
+declare module 'astro:manifest/server' {
+	type ServerConfigSerialized = import('./dist/types/public/manifest.js').ServerConfigSerialized;
+	const manifest: ServerConfigSerialized;
+	export default manifest;
+}
+
+declare module 'astro:manifest/client' {
+	type ClientConfigSerialized = import('./dist/types/public/manifest.js').ClientConfigSerialized;
+	const manifest: ClientConfigSerialized;
+	export default manifest;
+}
+
 declare module 'astro:components' {
 	export * from 'astro/components';
 }

packages/astro/src/core/config/schema.ts

@@ -97,6 +97,7 @@ export const ASTRO_CONFIG_DEFAULTS = {
 		contentIntellisense: false,
 		responsiveImages: false,
 		svg: false,
+		serializeManifest: false,
 	},
 } satisfies AstroUserConfig & { server: { open: boolean } };
 
@@ -589,6 +590,10 @@ export const AstroConfigSchema = z.object({
 					}
 					return svgConfig;
 				}),
+			serializeManifest: z
+				.boolean()
+				.optional()
+				.default(ASTRO_CONFIG_DEFAULTS.experimental.serializeManifest),
 		})
 		.strict(
 			`Invalid or outdated experimental feature.\nCheck for incorrect spelling or outdated Astro version.\nSee https://docs.astro.build/en/reference/experimental-flags/ for a list of all current experiments.`,

packages/astro/src/core/create-vite.ts

@@ -16,6 +16,7 @@ import { createEnvLoader } from '../env/env-loader.js';
 import { astroEnv } from '../env/vite-plugin-env.js';
 import { importMetaEnv } from '../env/vite-plugin-import-meta-env.js';
 import astroInternationalization from '../i18n/vite-plugin-i18n.js';
+import astroVirtualManifestPlugin from '../manifest/virtual-module.js';
 import astroPrefetch from '../prefetch/vite-plugin-prefetch.js';
 import astroDevToolbar from '../toolbar/vite-plugin-dev-toolbar.js';
 import astroTransitions from '../transitions/vite-plugin-transitions.js';
@@ -141,6 +142,7 @@ export async function createVite(
 			exclude: ['astro', 'node-fetch'],
 		},
 		plugins: [
+			astroVirtualManifestPlugin({ settings, logger }),
 			configAliasVitePlugin({ settings }),
 			astroLoadFallbackPlugin({ fs, root: settings.config.root }),
 			astroVitePlugin({ settings, logger }),

packages/astro/src/core/errors/errors-data.ts

@@ -1782,6 +1782,18 @@ export const ActionCalledFromServerError = {
 	hint: 'See the `Astro.callAction()` reference for usage examples: https://docs.astro.build/en/reference/api-reference/#callaction',
 } satisfies ErrorData;
 
+/**
+ * @docs
+ * @description
+ * Cannot the module without enabling the experimental feature
+ */
+export const CantUseManifestModule = {
+	name: 'CantUseManifestModule',
+	title: 'Cannot the module without enabling the experimental feature.',
+	message: (moduleName) =>
+		`Cannot import the module "${moduleName}" because the experimental feature is disabled. Enable \`experimental.serializeManifest\` in your \`astro.config.mjs\` `,
+} satisfies ErrorData;
+
 // Generic catch-all - Only use this in extreme cases, like if there was a cosmic ray bit flip.
 export const UnknownError = { name: 'UnknownError', title: 'Unknown Error.' } satisfies ErrorData;
 

packages/astro/src/manifest/virtual-module.ts

@@ -0,0 +1,102 @@
+import type { Plugin } from 'vite';
+import { CantUseManifestModule } from '../core/errors/errors-data.js';
+import { AstroError, AstroErrorData } from '../core/errors/index.js';
+import type { Logger } from '../core/logger/core.js';
+import type { AstroSettings } from '../types/astro.js';
+import type {
+	AstroConfig,
+	ClientConfigSerialized,
+	ServerConfigSerialized,
+} from '../types/public/index.js';
+
+const VIRTUAL_SERVER_ID = 'astro:manifest/server';
+const RESOLVED_VIRTUAL_SERVER_ID = '\0' + VIRTUAL_SERVER_ID;
+const VIRTUAL_CLIENT_ID = 'astro:manifest/client';
+const RESOLVED_VIRTUAL_CLIENT_ID = '\0' + VIRTUAL_CLIENT_ID;
+
+export default function virtualModulePlugin({
+	settings,
+	logger: _logger,
+}: { settings: AstroSettings; logger: Logger }): Plugin {
+	return {
+		enforce: 'pre',
+		name: 'astro-manifest-plugin',
+		resolveId(id) {
+			// Resolve the virtual module
+			if (VIRTUAL_SERVER_ID === id) {
+				return RESOLVED_VIRTUAL_SERVER_ID;
+			} else if (VIRTUAL_CLIENT_ID === id) {
+				return RESOLVED_VIRTUAL_CLIENT_ID;
+			}
+		},
+		load(id, opts) {
+			// client
+			if (id === RESOLVED_VIRTUAL_CLIENT_ID) {
+				if (!settings.config.experimental.serializeManifest) {
+					throw new AstroError({
+						...CantUseManifestModule,
+						message: CantUseManifestModule.message(VIRTUAL_CLIENT_ID),
+					});
+				}
+				// There's nothing wrong about using `/client` on the server
+				return `${serializeClientConfig(settings.config)};`;
+			}
+			// server
+			else if (id == RESOLVED_VIRTUAL_SERVER_ID) {
+				if (!settings.config.experimental.serializeManifest) {
+					throw new AstroError({
+						...CantUseManifestModule,
+						message: CantUseManifestModule.message(VIRTUAL_SERVER_ID),
+					});
+				}
+				if (!opts?.ssr) {
+					throw new AstroError({
+						...AstroErrorData.ServerOnlyModule,
+						message: AstroErrorData.ServerOnlyModule.message(VIRTUAL_SERVER_ID),
+					});
+				}
+				return `${serializeServerConfig(settings.config)};`;
+			}
+		},
+	};
+}
+
+function serializeClientConfig(config: AstroConfig): string {
+	const serClientConfig: ClientConfigSerialized = {
+		base: config.base,
+		i18n: config.i18n,
+		build: {
+			format: config.build.format,
+			redirects: config.build.redirects,
+		},
+		trailingSlash: config.trailingSlash,
+		compressHTML: config.compressHTML,
+		site: config.site,
+		legacy: config.legacy,
+	};
+
+	const output = [];
+	for (const [key, value] of Object.entries(serClientConfig)) {
+		output.push(`export const ${key} = ${JSON.stringify(value)};`);
+	}
+	return output.join('\n') + '\n';
+}
+
+function serializeServerConfig(config: AstroConfig): string {
+	const serverConfig: ServerConfigSerialized = {
+		build: {
+			client: config.build.client,
+			server: config.build.server,
+		},
+		cacheDir: config.cacheDir,
+		outDir: config.outDir,
+		publicDir: config.publicDir,
+		srcDir: config.srcDir,
+		root: config.root,
+	};
+	const output = [];
+	for (const [key, value] of Object.entries(serverConfig)) {
+		output.push(`export const ${key} = ${JSON.stringify(value)};`);
+	}
+	return output.join('\n') + '\n';
+}

packages/astro/src/types/public/config.ts

@@ -2059,6 +2059,19 @@ export interface ViteUserConfig extends OriginalViteUserConfig {
 					 */
 					mode: SvgRenderMode;
 			  };
+
+		/**
+		 * @name experimental.serializeManifest
+		 * @type {boolean}
+		 * @default `false`
+		 * @version 5.x
+		 * @description
+		 *
+		 * Allows to use the virtual modules `astro:manifest/server` and `astro:manifest/client`.
+		 *
+		 * These two virtual modules contain a serializable subset of the Astro configuration.
+		 */
+		serializeManifest?: boolean;
 	};
 }
 

packages/astro/src/types/public/index.ts

@@ -9,6 +9,7 @@ export type * from './context.js';
 export type * from './preview.js';
 export type * from './content.js';
 export type * from './common.js';
+export type * from './manifest.js';
 
 export type { AstroIntegrationLogger } from '../../core/logger/core.js';
 export type { ToolbarServerHelpers } from '../../runtime/client/dev-toolbar/helpers.js';

packages/astro/src/types/public/manifest.ts

@@ -0,0 +1,19 @@
+import type { AstroConfig } from './config.js';
+
+export type SerializedClientBuild = Pick<AstroConfig['build'], 'format' | 'redirects'>;
+
+export type SerializedServerBuild = Pick<AstroConfig['build'], 'client' | 'server'>;
+
+export type ClientConfigSerialized = Pick<
+	AstroConfig,
+	'base' | 'i18n' | 'trailingSlash' | 'compressHTML' | 'site' | 'legacy'
+> & {
+	build: SerializedClientBuild;
+};
+
+export type ServerConfigSerialized = Pick<
+	AstroConfig,
+	'cacheDir' | 'outDir' | 'publicDir' | 'srcDir' | 'root'
+> & {
+	build: SerializedServerBuild;
+};

packages/astro/test/fixtures/astro-manifest/astro.config.mjs

@@ -0,0 +1,13 @@
+import { defineConfig } from "astro/config";
+
+// https://astro.build/config
+export default defineConfig({
+	site: "https://astro.build/",
+	experimental: {
+		serializeManifest: true,
+	},
+	i18n: {
+		locales: ["en", "fr"],
+		defaultLocale: "en",
+	}
+});

packages/astro/test/fixtures/astro-manifest/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "@test/astro-manifest",
+  "version": "0.0.0",
+  "private": true,
+  "dependencies": {
+    "astro": "workspace:*"
+  }
+}

packages/astro/test/fixtures/astro-manifest/src/pages/client.astro

@@ -0,0 +1,20 @@
+---
+---
+
+<!DOCTYPE html>
+<html lang="en">
+<head>
+	<meta charset="UTF-8"/>
+	<meta name="viewport" content="width=device-width, initial-scale=1.0"/>
+	<title>Document</title>
+</head>
+<body>
+<h1>Hello, World!</h1>
+<p>Welcome to this Astro page.</p>
+<script>
+	import { outDir } from "astro:manifest/server"
+
+	console.log(outDir)
+</script>
+</body>
+</html>

packages/astro/test/fixtures/astro-manifest/src/pages/index.astro

@@ -0,0 +1,19 @@
+
+---
+import { base, i18n, trailingSlash, compressHTML, site, legacy, build } from "astro:manifest/client";
+
+const config = JSON.stringify({ base, i18n, build, trailingSlash, compressHTML, site, legacy });
+---
+<!DOCTYPE html>
+<html lang="en">
+<head>
+	<meta charset="UTF-8"/>
+	<meta name="viewport" content="width=device-width, initial-scale=1.0"/>
+	<title>Document</title>
+</head>
+<body>
+	<h1>Hello, World!</h1>
+	<p>Welcome to this Astro page.</p>
+	<p id="config">{config}</p>
+</body>
+</html>

packages/astro/test/fixtures/astro-manifest/src/pages/server.astro

@@ -0,0 +1,21 @@
+---
+import { root, outDir, srcDir, build, cacheDir } from "astro:manifest/server";
+---
+<!DOCTYPE html>
+<html lang="en">
+<head>
+	<meta charset="UTF-8"/>
+	<meta name="viewport" content="width=device-width, initial-scale=1.0"/>
+	<title>Document</title>
+</head>
+<body>
+<h1>Hello, World!</h1>
+<p>Welcome to this Astro page.</p>
+<p id="out-dir">{outDir}</p>
+<p id="src-dir">{srcDir}</p>
+<p id="root">{root}</p>
+<p id="cache-dir">{cacheDir}</p>
+<p id="build-client">{build.client}</p>
+<p id="build-server">{build.server}</p>
+</body>
+</html>