Unflag Server Islands

.changeset/strange-sheep-film.md

@@ -0,0 +1,11 @@
+---
+'astro': minor
+---
+
+Unflag Server Islands
+
+[Server Islands](https://astro.build/blog/future-of-astro-server-islands/), Astro's solution for highly cacheable pages of mixed static and dynamic content, is now unflagged and is available to all.
+
+To use a server island, simply add `server:defer` to any Astro component. It will be rendered dynamically at runtime outside the context of the rest of the page, allowing you to add longer cache headers for the pages, or even prerender them.
+
+If you are using Server Islands today, simply remove the `expermental.serverIslands` option from your Astro config.

examples/server-islands/astro.config.mjs

@@ -12,7 +12,4 @@ export default defineConfig({
 		tailwind({ applyBaseStyles: false })
 	],
 	devToolbar: { enabled: false },
-	experimental: {
-		serverIslands: true,
-	}
 });

packages/astro/e2e/fixtures/server-islands/astro.config.mjs

@@ -10,7 +10,4 @@ export default defineConfig({
 	adapter: nodejs({ mode: 'standalone' }),
 	integrations: [react(), mdx()],
 	trailingSlash: process.env.TRAILING_SLASH ?? 'always',
-	experimental: {
-		serverIslands: true,
-	}
 });

packages/astro/src/core/build/index.ts

@@ -205,6 +205,13 @@ class AstroBuilder {
 		};
 
 		const { internals, ssrOutputChunkNames, contentFileNames } = await viteBuild(opts);
+
+		const hasServerIslands = this.settings.serverIslandNameMap.size > 0;
+		// Error if there are server islands but no adapter provided.
+		if(hasServerIslands && !this.settings.adapter) {
+			throw new AstroError(AstroErrorData.NoAdapterInstalledServerIslands);
+		}
+
 		await staticBuild(opts, internals, ssrOutputChunkNames, contentFileNames);
 
 		// Write any additionally generated assets to disk.
@@ -225,11 +232,7 @@ class AstroBuilder {
 			routes: Object.values(allPages)
 				.flat()
 				.map((pageData) => pageData.route)
-				.concat(
-					this.settings.config.experimental.serverIslands
-						? [getServerIslandRouteData(this.settings.config)]
-						: [],
-				),
+				.concat(hasServerIslands ? getServerIslandRouteData(this.settings.config) : []),
 			logging: this.logger,
 			cacheManifest: internals.cacheManifestUsed,
 		});

packages/astro/src/core/build/plugins/plugin-ssr.ts

@@ -171,13 +171,10 @@ function generateSSRCode(settings: AstroSettings, adapter: AstroAdapter, middlew
 		`import * as serverEntrypointModule from '${ADAPTER_VIRTUAL_MODULE_ID}';`,
 		`import { manifest as defaultManifest } from '${SSR_MANIFEST_VIRTUAL_MODULE_ID}';`,
 		edgeMiddleware ? `` : `import { onRequest as middleware } from '${middlewareId}';`,
-		settings.config.experimental.serverIslands
-			? `import { serverIslandMap } from '${VIRTUAL_ISLAND_MAP_ID}';`
-			: '',
+		`import { serverIslandMap } from '${VIRTUAL_ISLAND_MAP_ID}';`,
 	];
 
 	const contents = [
-		settings.config.experimental.serverIslands ? '' : `const serverIslandMap = new Map()`,
 		edgeMiddleware ? `const middleware = (_, next) => next()` : '',
 		`const _manifest = Object.assign(defaultManifest, {`,
 		`    pageMap,`,

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

@@ -91,7 +91,6 @@ export const ASTRO_CONFIG_DEFAULTS = {
 	experimental: {
 		contentCollectionCache: false,
 		clientPrerender: false,
-		serverIslands: false,
 		contentIntellisense: false,
 	},
 } satisfies AstroUserConfig & { server: { open: boolean } };
@@ -521,10 +520,6 @@ export const AstroConfigSchema = z.object({
 				.boolean()
 				.optional()
 				.default(ASTRO_CONFIG_DEFAULTS.experimental.clientPrerender),
-			serverIslands: z
-				.boolean()
-				.optional()
-				.default(ASTRO_CONFIG_DEFAULTS.experimental.serverIslands),
 			contentIntellisense: z
 				.boolean()
 				.optional()

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

@@ -158,7 +158,7 @@ export async function createVite(
 			astroInternationalization({ settings }),
 			vitePluginActions({ fs, settings }),
 			vitePluginUserActions({ settings }),
-			settings.config.experimental.serverIslands && vitePluginServerIslands({ settings }),
+			vitePluginServerIslands({ settings }),
 			astroContainer(),
 		],
 		publicDir: fileURLToPath(settings.config.publicDir),

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

@@ -397,6 +397,18 @@ export const NoAdapterInstalled = {
 	hint: 'See https://docs.astro.build/en/guides/server-side-rendering/ for more information.',
 } satisfies ErrorData;
 /**
+ * @docs
+ * @see
+ * - [Server-side Rendering](https://docs.astro.build/en/guides/server-side-rendering/)
+ * @description
+ * To use server islands, the same constraints exist as for sever-side rendering, so an adapter is needed.
+ */
+export const NoAdapterInstalledServerIslands = {
+	name: 'NoAdapterInstalledServerIslands',
+	title: 'Cannot use Server Islands without an adapter.',
+	message: `Cannot use server islands without an adapter. Please install and configure the appropriate server adapter for your final deployment.`,
+	hint: 'See https://docs.astro.build/en/guides/server-side-rendering/ for more information.',
+} satisfies ErrorData;/**
  * @docs
  * @description
  * No import statement was found for one of the components. If there is an import statement, make sure you are using the same identifier in both the imports and the component usage.

packages/astro/test/fixtures/server-islands/hybrid/astro.config.mjs

@@ -6,7 +6,4 @@ export default defineConfig({
   integrations: [
     svelte()
   ],
-  experimental: {
-    serverIslands: true,
-  }
 });

packages/astro/test/fixtures/server-islands/ssr/astro.config.mjs

@@ -6,8 +6,5 @@ export default defineConfig({
   integrations: [
     svelte()
   ],
-  experimental: {
-    serverIslands: true,
-  }
 });
 

packages/astro/test/server-islands.test.js

@@ -63,13 +63,14 @@ describe('Server islands', () => {
 		before(async () => {
 			fixture = await loadFixture({
 				root: './fixtures/server-islands/hybrid',
-				adapter: testAdapter(),
 			});
 		});
 
 		describe('build', () => {
 			before(async () => {
-				await fixture.build();
+				await fixture.build({
+					adapter: testAdapter()
+				});
 			});
 
 			it('Omits the island HTML from the static HTML', async () => {
@@ -83,5 +84,18 @@ describe('Server islands', () => {
 				assert.equal(serverIslandScript.length, 1, 'has the island script');
 			});
 		});
+
+		describe('build (no adapter)', () => {
+			it('Errors during the build', async () => {
+				try {
+					await fixture.build({
+						adapter: undefined
+					});
+					assert.equal(true, false, 'should not have succeeded');
+				} catch(err) {
+					assert.equal(err.title, 'Cannot use Server Islands without an adapter.');
+				}
+			});
+		});
 	});
 });