Fix prerendered page handling on Deno (#6284)

* fix(deno): handle prerendered pages

* test(deno): add prerender test

* fix: defensively access vite.build.rollupOptions.external

* fix(deno): support other formats of rollupOptions.external

* fix(deno): crawl prerendered files for match

* fix(deno): ignore deno error in server file

* fix(deno): cross-platform serve file

.changeset/shaggy-moons-judge.md

@@ -0,0 +1,5 @@
+---
+'@astrojs/deno': patch
+---
+
+Fix prerendered page behavior

examples/deno/package.json

@@ -6,7 +6,7 @@
     "dev": "astro dev",
     "start": "astro dev",
     "build": "astro build",
-    "preview": "deno run --allow-net --allow-read ./dist/server/entry.mjs",
+    "preview": "deno run --allow-net --allow-read --allow-env ./dist/server/entry.mjs",
     "astro": "astro"
   },
   "dependencies": {

examples/deno/src/pages/index.astro

@@ -1,5 +1,7 @@
 ---
 import Layout from '../components/Layout.astro';
+
+export const prerender = true;
 ---
 
 <Layout title="Welcome to Astro (on Deno).">

packages/integrations/deno/package.json

@@ -20,6 +20,7 @@
   "exports": {
     ".": "./dist/index.js",
     "./server.js": "./dist/server.js",
+    "./__deno_imports.js": "./dist/__deno_imports.js",
     "./package.json": "./package.json"
   },
   "scripts": {

packages/integrations/deno/src/__deno_imports.ts

@@ -0,0 +1,10 @@
+// This file is a shim for any Deno-specific imports!
+// It will be replaced in the final Deno build.
+// 
+// This allows us to prerender pages in Node.
+export class Server {
+	listenAndServe() {}
+}
+
+export function serveFile() {}
+export function fromFileUrl() {}

packages/integrations/deno/src/index.ts

@@ -20,6 +20,16 @@ const SHIM = `globalThis.process = {
 	env: Deno.env.toObject(),
 };`;
 
+const DENO_VERSION = `0.177.0`
+
+// We shim deno-specific imports so we can run the code in Node
+// to prerender pages. In the final Deno build, this import is 
+// replaced with the Deno-specific contents listed below.
+const DENO_IMPORTS_SHIM = `@astrojs/deno/__deno_imports.js`;
+const DENO_IMPORTS = `export { Server } from "https://deno.land/std@${DENO_VERSION}/http/server.ts"
+export { serveFile } from 'https://deno.land/std@${DENO_VERSION}/http/file_server.ts';
+export { fromFileUrl } from "https://deno.land/std@${DENO_VERSION}/path/mod.ts";`
+
 export function getAdapter(args?: Options): AstroAdapter {
 	return {
 		name: '@astrojs/deno',
@@ -29,6 +39,18 @@ export function getAdapter(args?: Options): AstroAdapter {
 	};
 }
 
+const denoImportsShimPlugin = {
+  name: '@astrojs/deno:shim',
+  setup(build: esbuild.PluginBuild) {
+    build.onLoad({ filter: /__deno_imports\.js$/ }, async (args) => {
+      return {
+        contents: DENO_IMPORTS,
+        loader: 'js',
+      }
+    })
+  },
+}
+
 export default function createIntegration(args?: Options): AstroIntegration {
 	let _buildConfig: BuildConfig;
 	let _vite: any;
@@ -49,8 +71,11 @@ export default function createIntegration(args?: Options): AstroIntegration {
 			'astro:build:setup': ({ vite, target }) => {
 				if (target === 'server') {
 					_vite = vite;
-					vite.resolve = vite.resolve || {};
+					vite.resolve = vite.resolve ?? {};
-					vite.resolve.alias = vite.resolve.alias || {};
+					vite.resolve.alias = vite.resolve.alias ?? {};
+					vite.build = vite.build ?? {};
+					vite.build.rollupOptions = vite.build.rollupOptions ?? {};
+					vite.build.rollupOptions.external = vite.build.rollupOptions.external ?? [];
 
 					const aliases = [{ find: 'react-dom/server', replacement: 'react-dom/server.browser' }];
 
@@ -61,10 +86,15 @@ export default function createIntegration(args?: Options): AstroIntegration {
 							(vite.resolve.alias as Record<string, string>)[alias.find] = alias.replacement;
 						}
 					}
-
 					vite.ssr = {
 						noExternal: true,
 					};
+
+					if (Array.isArray(vite.build.rollupOptions.external)) {
+						vite.build.rollupOptions.external.push(DENO_IMPORTS_SHIM);		
+					} else if (typeof vite.build.rollupOptions.external !== 'function') {
+						vite.build.rollupOptions.external = [vite.build.rollupOptions.external, DENO_IMPORTS_SHIM]
+					}
 				}
 			},
 			'astro:build:done': async () => {
@@ -80,6 +110,9 @@ export default function createIntegration(args?: Options): AstroIntegration {
 					format: 'esm',
 					bundle: true,
 					external: ['@astrojs/markdown-remark'],
+					plugins: [
+						denoImportsShimPlugin
+					],
 					banner: {
 						js: SHIM,
 					},

packages/integrations/deno/src/server.ts

@@ -3,9 +3,7 @@ import type { SSRManifest } from 'astro';
 import { App } from 'astro/app';
 
 // @ts-ignore
-import { Server } from 'https://deno.land/std@0.167.0/http/server.ts';
+import { Server, serveFile, fromFileUrl } from '@astrojs/deno/__deno_imports.js';
-// @ts-ignore
-import { fetch } from 'https://deno.land/x/file_fetch/mod.ts';
 
 interface Options {
 	port?: number;
@@ -16,6 +14,17 @@ interface Options {
 let _server: Server | undefined = undefined;
 let _startPromise: Promise<void> | undefined = undefined;
 
+async function* getPrerenderedFiles(clientRoot: URL): AsyncGenerator<URL> {
+	// @ts-ignore
+	for await (const ent of Deno.readDir(clientRoot)) {
+		if (ent.isDirectory) {
+			yield* getPrerenderedFiles(new URL(`./${ent.name}/`, clientRoot))
+		} else if (ent.name.endsWith('.html')) {
+			yield new URL(`./${ent.name}`, clientRoot)
+		}
+	}
+}
+
 export function start(manifest: SSRManifest, options: Options) {
 	if (options.start === false) {
 		return;
@@ -40,7 +49,24 @@ export function start(manifest: SSRManifest, options: Options) {
 		// try to fetch a static file instead
 		const url = new URL(request.url);
 		const localPath = new URL('./' + app.removeBase(url.pathname), clientRoot);
-		const fileResp = await fetch(localPath.toString());
+
+		let fileResp = await serveFile(request, fromFileUrl(localPath));
+
+		// Attempt to serve `index.html` if 404
+		if (fileResp.status == 404) {
+			let fallback;
+			for await (const file of getPrerenderedFiles(clientRoot)) {
+				const pathname = file.pathname.replace(/\/(index)?\.html$/, '');
+				if (localPath.pathname.endsWith(pathname)) {
+					fallback = file;
+					break;
+				}
+			}
+			if (fallback) {
+				fileResp = await serveFile(request, fromFileUrl(fallback));
+			}
+		}
+
 
 		// If the static file can't be found
 		if (fileResp.status == 404) {

packages/integrations/deno/test/basics.test.ts

@@ -68,7 +68,7 @@ Deno.test({
 			resp = await fetch(new URL(href!, baseUrl));
 			assertEquals(resp.status, 200);
 			const ct = resp.headers.get('content-type');
-			assertEquals(ct, 'text/css');
+			assertEquals(ct, 'text/css; charset=UTF-8');
 			await resp.body!.cancel();
 		});
 	},
@@ -143,3 +143,24 @@ Deno.test({
 	sanitizeResources: false,
 	sanitizeOps: false,
 });
+
+
+Deno.test({
+	name: 'perendering',
+	permissions: defaultTestPermissions,
+	async fn() {
+		await startApp(async (baseUrl: URL) => {
+			const resp = await fetch(new URL('/prerender', baseUrl));
+			assertEquals(resp.status, 200);
+
+			const html = await resp.text();
+			assert(html);
+
+			const doc = new DOMParser().parseFromString(html, `text/html`);
+			const h1 = doc!.querySelector('h1');
+			assertEquals(h1!.innerText, 'test');
+		});
+	},
+	sanitizeResources: false,
+	sanitizeOps: false,
+});

packages/integrations/deno/test/fixtures/basics/src/pages/prerender.astro

@@ -0,0 +1,9 @@
+---
+export const prerender = true; 
+---
+
+<html>
+	<body>
+		<h1>test</h1>
+	</body>
+</html>