feat(@astrojs/netlify): edge middleware support (#7632)

Co-authored-by: Bjorn Lu <bjornlu.dev@gmail.com>
Co-authored-by: Yan Thomas <61414485+Yan-Thomas@users.noreply.github.com>

.changeset/great-days-judge.md

@@ -0,0 +1,10 @@
+---
+'@astrojs/netlify': minor
+---
+
+When a project uses the new option Astro `build.excludeMiddleware`, the
+`@astrojs/netlify/functions` adapter will automatically create an Edge Middleware
+that will automatically communicate with the Astro Middleware.
+
+Check the [documentation](https://github.com/withastro/astro/blob/main/packages/integrations/netlify/README.md#edge-middleware-with-astro-middleware) for more details.
+

.github/workflows/ci.yml

@@ -136,7 +136,7 @@ jobs:
       - name: Use Deno
         uses: denoland/setup-deno@v1
         with:
-          deno-version: v1.34.1
+          deno-version: v1.35.0
 
       - name: Install dependencies
         run: pnpm install

packages/integrations/netlify/README.md

@@ -115,6 +115,65 @@ Once you run `astro build` there will be a `dist/_redirects` file. Netlify will
 > **Note**
 > You can still include a `public/_redirects` file for manual redirects. Any redirects you specify in the redirects config are appended to the end of your own.
 
+
+### Edge Middleware with Astro middleware
+
+The `@astrojs/netlify/functions` adapter can automatically create an edge function that will act as "Edge Middleware", from an Astro middleware in your code base.
+
+This is an opt-in feature and the `build.excludeMiddleware` option needs to be set to `true`:
+
+```js
+// astro.config.mjs
+import { defineConfig } from 'astro/config';
+import netlify from '@astrojs/netlify/functions';
+export default defineConfig({
+  output: 'server',
+  adapter: netlify(),
+  build: {
+    excludeMiddleware: true,
+  },
+});
+```
+
+Optionally, you can create a file recognized by the adapter named `netlify-edge-middleware.(js|ts)` in the [`srcDir`](https://docs.astro.build/en/reference/configuration-reference/#srcdir) folder to create [`Astro.locals`](https://docs.astro.build/en/reference/api-reference/#astrolocals).
+
+Typings require the [`https://edge.netlify.com`](https://docs.netlify.com/edge-functions/api/#reference) types.
+
+> Netlify edge functions run in a Deno environment, so you would need to import types using URLs.
+> 
+> You can find more in the [Netlify documentation page](https://docs.netlify.com/edge-functions/api/#runtime-environment)
+
+```ts
+// src/netlify-edge-middleware.ts
+import type { Context } from "https://edge.netlify.com";
+
+export default function ({ request, context }: { request: Request, context: Context }): object {
+  // do something with request and context
+  return {
+    title: "Spider-man's blog",
+  };
+}
+```
+
+The data returned by this function will be passed to Astro middleware.
+
+The function:
+
+- must export a **default** function;
+- must **return** an `object`;
+- accepts an object with a `request` and `context` as properties;
+- `request` is typed as [`Request`](https://developer.mozilla.org/en-US/docs/Web/API/Request);
+- `context` is typed as [`Context`](https://docs.netlify.com/edge-functions/api/#edge-function-types);
+
+#### Limitations and constraints
+
+When you opt-in to this feature, there are a few constraints to note:
+
+- The Edge middleware will always be the **first** function to receive the `Request` and the last function to receive `Response`. This is an architectural constraint that follows the [boundaries set by Netlify](https://docs.netlify.com/edge-functions/overview/#use-cases).
+- Only `request` and `context` may be used to produce an `Astro.locals` object. Operations like redirects, etc. should be delegated to Astro middleware.
+- `Astro.locals` **must be serializable**. Failing to do so will result in a **runtime error**. This means that you **cannot** store complex types like `Map`, `function`, `Set`, etc.
+
+
 ## Usage
 
 [Read the full deployment guide here.](https://docs.astro.build/en/guides/deploy/netlify/)

packages/integrations/netlify/package.json

@@ -33,8 +33,8 @@
     "build:ci": "astro-scripts build \"src/**/*.ts\"",
     "dev": "astro-scripts dev \"src/**/*.ts\"",
     "test-fn": "mocha --exit --timeout 20000 --file \"./test/setup.js\" test/functions/",
-    "test-edge": "deno test --allow-run --allow-read --allow-net --allow-env ./test/edge-functions/",
-    "test": "npm run test-fn"
+    "test-edge": "deno test --allow-run --allow-read --allow-net --allow-env --allow-write ./test/edge-functions/",
+    "test": "pnpm test-fn"
   },
   "dependencies": {
     "@astrojs/underscore-redirects": "^0.2.0",

packages/integrations/netlify/src/integration-edge-functions.ts

@@ -1,21 +1,10 @@
 import type { AstroAdapter, AstroConfig, AstroIntegration, RouteData } from 'astro';
-import esbuild from 'esbuild';
-import * as fs from 'fs';
-import * as npath from 'path';
-import { fileURLToPath } from 'url';
-import { createRedirects } from './shared.js';
-
-interface BuildConfig {
-	server: URL;
-	client: URL;
-	serverEntry: string;
-	assets: string;
-}
-
-const SHIM = `globalThis.process = {
-	argv: [],
-	env: Deno.env.toObject(),
-};`;
+import {
+	bundleServerEntry,
+	createEdgeManifest,
+	createRedirects,
+	type NetlifyEdgeFunctionsOptions,
+} from './shared.js';
 
 export function getAdapter(): AstroAdapter {
 	return {
@@ -25,92 +14,10 @@ export function getAdapter(): AstroAdapter {
 	};
 }
 
-interface NetlifyEdgeFunctionsOptions {
-	dist?: URL;
-}
-
-interface NetlifyEdgeFunctionManifestFunctionPath {
-	function: string;
-	path: string;
-}
-
-interface NetlifyEdgeFunctionManifestFunctionPattern {
-	function: string;
-	pattern: string;
-}
-
-type NetlifyEdgeFunctionManifestFunction =
-	| NetlifyEdgeFunctionManifestFunctionPath
-	| NetlifyEdgeFunctionManifestFunctionPattern;
-
-interface NetlifyEdgeFunctionManifest {
-	functions: NetlifyEdgeFunctionManifestFunction[];
-	version: 1;
-}
-
-async function createEdgeManifest(routes: RouteData[], entryFile: string, dir: URL) {
-	const functions: NetlifyEdgeFunctionManifestFunction[] = [];
-	for (const route of routes) {
-		if (route.pathname) {
-			functions.push({
-				function: entryFile,
-				path: route.pathname,
-			});
-		} else {
-			functions.push({
-				function: entryFile,
-				// Make route pattern serializable to match expected
-				// Netlify Edge validation format. Mirrors Netlify's own edge bundler:
-				// https://github.com/netlify/edge-bundler/blob/main/src/manifest.ts#L34
-				pattern: route.pattern.source.replace(/\\\//g, '/').toString(),
-			});
-		}
-	}
-
-	const manifest: NetlifyEdgeFunctionManifest = {
-		functions,
-		version: 1,
-	};
-
-	const baseDir = new URL('./.netlify/edge-functions/', dir);
-	await fs.promises.mkdir(baseDir, { recursive: true });
-
-	const manifestURL = new URL('./manifest.json', baseDir);
-	const _manifest = JSON.stringify(manifest, null, '  ');
-	await fs.promises.writeFile(manifestURL, _manifest, 'utf-8');
-}
-
-async function bundleServerEntry({ serverEntry, server }: BuildConfig, vite: any) {
-	const entryUrl = new URL(serverEntry, server);
-	const pth = fileURLToPath(entryUrl);
-	await esbuild.build({
-		target: 'es2020',
-		platform: 'browser',
-		entryPoints: [pth],
-		outfile: pth,
-		allowOverwrite: true,
-		format: 'esm',
-		bundle: true,
-		external: ['@astrojs/markdown-remark'],
-		banner: {
-			js: SHIM,
-		},
-	});
-
-	// Remove chunks, if they exist. Since we have bundled via esbuild these chunks are trash.
-	try {
-		const chunkFileNames =
-			vite?.build?.rollupOptions?.output?.chunkFileNames ?? `chunks/chunk.[hash].mjs`;
-		const chunkPath = npath.dirname(chunkFileNames);
-		const chunksDirUrl = new URL(chunkPath + '/', server);
-		await fs.promises.rm(chunksDirUrl, { recursive: true, force: true });
-	} catch {}
-}
-
 export function netlifyEdgeFunctions({ dist }: NetlifyEdgeFunctionsOptions = {}): AstroIntegration {
 	let _config: AstroConfig;
 	let entryFile: string;
-	let _buildConfig: BuildConfig;
+	let _buildConfig: AstroConfig['build'];
 	let _vite: any;
 	return {
 		name: '@astrojs/netlify/edge-functions',
@@ -164,7 +71,8 @@ export function netlifyEdgeFunctions({ dist }: NetlifyEdgeFunctionsOptions = {})
 				}
 			},
 			'astro:build:done': async ({ routes, dir }) => {
-				await bundleServerEntry(_buildConfig, _vite);
+				const entryUrl = new URL(_buildConfig.serverEntry, _buildConfig.server);
+				await bundleServerEntry(entryUrl, _buildConfig.server, _vite);
 				await createEdgeManifest(routes, entryFile, _config.root);
 				const dynamicTarget = `/.netlify/edge-functions/${entryFile}`;
 				const map: [RouteData, string][] = routes.map((route) => {

packages/integrations/netlify/src/integration-functions.ts

@@ -1,8 +1,12 @@
 import type { AstroAdapter, AstroConfig, AstroIntegration, RouteData } from 'astro';
 import { extname } from 'node:path';
-import { fileURLToPath } from 'node:url';
 import type { Args } from './netlify-functions.js';
 import { createRedirects } from './shared.js';
+import { fileURLToPath } from 'node:url';
+import { generateEdgeMiddleware } from './middleware.js';
+
+export const NETLIFY_EDGE_MIDDLEWARE_FILE = 'netlify-edge-middleware';
+export const ASTRO_LOCALS_HEADER = 'x-astro-locals';
 
 export function getAdapter(args: Args = {}): AstroAdapter {
 	return {
@@ -27,6 +31,7 @@ function netlifyFunctions({
 	let _config: AstroConfig;
 	let _entryPoints: Map<RouteData, URL>;
 	let ssrEntryFile: string;
+	let _middlewareEntryPoint: URL;
 	return {
 		name: '@astrojs/netlify',
 		hooks: {
@@ -40,7 +45,10 @@ function netlifyFunctions({
 					},
 				});
 			},
-			'astro:build:ssr': ({ entryPoints }) => {
+			'astro:build:ssr': async ({ entryPoints, middlewareEntryPoint }) => {
+				if (middlewareEntryPoint) {
+					_middlewareEntryPoint = middlewareEntryPoint;
+				}
 				_entryPoints = entryPoints;
 			},
 			'astro:config:done': ({ config, setAdapter }) => {
@@ -85,6 +93,18 @@ function netlifyFunctions({
 
 					await createRedirects(_config, routeToDynamicTargetMap, dir);
 				}
+				if (_middlewareEntryPoint) {
+					const outPath = fileURLToPath(new URL('./.netlify/edge-functions/', _config.root));
+					const netlifyEdgeMiddlewareHandlerPath = new URL(
+						NETLIFY_EDGE_MIDDLEWARE_FILE,
+						_config.srcDir
+					);
+					await generateEdgeMiddleware(
+						_middlewareEntryPoint,
+						outPath,
+						netlifyEdgeMiddlewareHandlerPath
+					);
+				}
 			},
 		},
 	};

packages/integrations/netlify/src/middleware.ts

@@ -0,0 +1,75 @@
+import { fileURLToPath, pathToFileURL } from 'node:url';
+import { join } from 'node:path';
+import { existsSync } from 'node:fs';
+import { ASTRO_LOCALS_HEADER } from './integration-functions.js';
+import { DENO_SHIM } from './shared.js';
+
+/**
+ * It generates a Netlify edge function.
+ *
+ */
+export async function generateEdgeMiddleware(
+	astroMiddlewareEntryPointPath: URL,
+	outPath: string,
+	netlifyEdgeMiddlewareHandlerPath: URL
+): Promise<URL> {
+	const entryPointPathURLAsString = JSON.stringify(
+		fileURLToPath(astroMiddlewareEntryPointPath).replace(/\\/g, '/')
+	);
+
+	const code = edgeMiddlewareTemplate(entryPointPathURLAsString, netlifyEdgeMiddlewareHandlerPath);
+	const bundledFilePath = join(outPath, 'edgeMiddleware.js');
+	const esbuild = await import('esbuild');
+	await esbuild.build({
+		stdin: {
+			contents: code,
+			resolveDir: process.cwd(),
+		},
+		target: 'es2020',
+		platform: 'browser',
+		outfile: bundledFilePath,
+		allowOverwrite: true,
+		format: 'esm',
+		bundle: true,
+		minify: false,
+		banner: {
+			js: DENO_SHIM,
+		},
+	});
+	return pathToFileURL(bundledFilePath);
+}
+
+function edgeMiddlewareTemplate(middlewarePath: string, netlifyEdgeMiddlewareHandlerPath: URL) {
+	const filePathEdgeMiddleware = fileURLToPath(netlifyEdgeMiddlewareHandlerPath);
+	let handlerTemplateImport = '';
+	let handlerTemplateCall = '{}';
+	if (existsSync(filePathEdgeMiddleware + '.js') || existsSync(filePathEdgeMiddleware + '.ts')) {
+		const stringified = JSON.stringify(filePathEdgeMiddleware.replace(/\\/g, '/'));
+		handlerTemplateImport = `import handler from ${stringified}`;
+		handlerTemplateCall = `handler({ request, context })`;
+	} else {
+	}
+	return `
+	${handlerTemplateImport}
+import { onRequest } from ${middlewarePath};
+import { createContext, trySerializeLocals } from 'astro/middleware';
+export default async function middleware(request, context) {
+	const url = new URL(request.url);
+	const ctx = createContext({ 
+		request,
+		params: {}
+	});
+	ctx.locals = ${handlerTemplateCall};
+	const next = async () => {	
+		request.headers.set(${JSON.stringify(ASTRO_LOCALS_HEADER)}, trySerializeLocals(ctx.locals));
+		return await context.next();
+	};
+
+	return onRequest(ctx, next);
+}
+
+export const config = {
+	path: "/*"
+}
+`;
+}

packages/integrations/netlify/src/netlify-functions.ts

@@ -2,6 +2,7 @@ import { polyfill } from '@astrojs/webapi';
 import { builder, type Handler } from '@netlify/functions';
 import type { SSRManifest } from 'astro';
 import { App } from 'astro/app';
+import { ASTRO_LOCALS_HEADER } from './integration-functions.js';
 
 polyfill(globalThis, {
 	exclude: 'window document',
@@ -80,8 +81,14 @@ export const createExports = (manifest: SSRManifest, args: Args) => {
 
 		const ip = headers['x-nf-client-connection-ip'];
 		Reflect.set(request, clientAddressSymbol, ip);
-
-		const response: Response = await app.render(request, routeData);
+		let locals = {};
+		if (request.headers.has(ASTRO_LOCALS_HEADER)) {
+			let localsAsString = request.headers.get(ASTRO_LOCALS_HEADER);
+			if (localsAsString) {
+				locals = JSON.parse(localsAsString);
+			}
+		}
+		const response: Response = await app.render(request, routeData, locals);
 		const responseHeaders = Object.fromEntries(response.headers.entries());
 
 		const responseContentType = parseContentType(responseHeaders['content-type']);

packages/integrations/netlify/src/shared.ts

@@ -1,6 +1,37 @@
 import { createRedirectsFromAstroRoutes } from '@astrojs/underscore-redirects';
 import type { AstroConfig, RouteData } from 'astro';
 import fs from 'node:fs';
+import { fileURLToPath } from 'url';
+import esbuild from 'esbuild';
+import npath from 'path';
+
+export const DENO_SHIM = `globalThis.process = {
+	argv: [],
+	env: Deno.env.toObject(),
+};`;
+
+export interface NetlifyEdgeFunctionsOptions {
+	dist?: URL;
+}
+
+export interface NetlifyEdgeFunctionManifestFunctionPath {
+	function: string;
+	path: string;
+}
+
+export interface NetlifyEdgeFunctionManifestFunctionPattern {
+	function: string;
+	pattern: string;
+}
+
+export type NetlifyEdgeFunctionManifestFunction =
+	| NetlifyEdgeFunctionManifestFunctionPath
+	| NetlifyEdgeFunctionManifestFunctionPattern;
+
+export interface NetlifyEdgeFunctionManifest {
+	functions: NetlifyEdgeFunctionManifestFunction[];
+	version: 1;
+}
 
 export async function createRedirects(
 	config: AstroConfig,
@@ -21,3 +52,63 @@ export async function createRedirects(
 	// If the file does not exist yet, appendFile() automatically creates it.
 	await fs.promises.appendFile(_redirectsURL, content, 'utf-8');
 }
+
+export async function createEdgeManifest(routes: RouteData[], entryFile: string, dir: URL) {
+	const functions: NetlifyEdgeFunctionManifestFunction[] = [];
+	for (const route of routes) {
+		if (route.pathname) {
+			functions.push({
+				function: entryFile,
+				path: route.pathname,
+			});
+		} else {
+			functions.push({
+				function: entryFile,
+				// Make route pattern serializable to match expected
+				// Netlify Edge validation format. Mirrors Netlify's own edge bundler:
+				// https://github.com/netlify/edge-bundler/blob/main/src/manifest.ts#L34
+				pattern: route.pattern.source.replace(/\\\//g, '/').toString(),
+			});
+		}
+	}
+
+	const manifest: NetlifyEdgeFunctionManifest = {
+		functions,
+		version: 1,
+	};
+
+	const baseDir = new URL('./.netlify/edge-functions/', dir);
+	await fs.promises.mkdir(baseDir, { recursive: true });
+
+	const manifestURL = new URL('./manifest.json', baseDir);
+	const _manifest = JSON.stringify(manifest, null, '  ');
+	await fs.promises.writeFile(manifestURL, _manifest, 'utf-8');
+}
+
+export async function bundleServerEntry(entryUrl: URL, serverUrl?: URL, vite?: any | undefined) {
+	const pth = fileURLToPath(entryUrl);
+	await esbuild.build({
+		target: 'es2020',
+		platform: 'browser',
+		entryPoints: [pth],
+		outfile: pth,
+		allowOverwrite: true,
+		format: 'esm',
+		bundle: true,
+		external: ['@astrojs/markdown-remark', 'astro/middleware'],
+		banner: {
+			js: DENO_SHIM,
+		},
+	});
+
+	// Remove chunks, if they exist. Since we have bundled via esbuild these chunks are trash.
+	if (vite && serverUrl) {
+		try {
+			const chunkFileNames =
+				vite?.build?.rollupOptions?.output?.chunkFileNames ?? `chunks/chunk.[hash].mjs`;
+			const chunkPath = npath.dirname(chunkFileNames);
+			const chunksDirUrl = new URL(chunkPath + '/', serverUrl);
+			await fs.promises.rm(chunksDirUrl, { recursive: true, force: true });
+		} catch {}
+	}
+}

packages/integrations/netlify/test/edge-functions/deps.ts

@@ -5,7 +5,7 @@ export {
 	assert,
 	assertExists,
 } from 'https://deno.land/std@0.132.0/testing/asserts.ts';
-export * from 'https://deno.land/x/deno_dom/deno-dom-wasm.ts';
+export { DOMParser } from 'https://deno.land/x/deno_dom@v0.1.35-alpha/deno-dom-wasm.ts';
 export * from 'https://deno.land/std@0.142.0/streams/conversion.ts';
 export * as cheerio from 'https://cdn.skypack.dev/cheerio?dts';
 export * as fs from 'https://deno.land/std/fs/mod.ts';

packages/integrations/netlify/test/edge-functions/dynamic-import.test.ts

@@ -1,10 +1,12 @@
-import { runBuild, runApp } from './test-utils.ts';
+import { loadFixture } from './test-utils.ts';
 import { assertEquals, assert, DOMParser } from './deps.ts';
 
 Deno.test({
 	name: 'Dynamic imports',
+	permissions: 'inherit',
 	async fn() {
-		await runBuild('./fixtures/dynimport/');
+		const { runApp, runBuild } = await loadFixture('./fixtures/dynimport/');
+		await runBuild();
 		const stop = await runApp('./fixtures/dynimport/prod.js');
 
 		try {
@@ -14,8 +16,10 @@ Deno.test({
 
 			assert(html, 'got some html');
 			const doc = new DOMParser().parseFromString(html, `text/html`);
-			const div = doc.querySelector('#thing');
-			assert(div, 'div exists');
+			if (doc) {
+				const div = doc.querySelector('#thing');
+				assert(div, 'div exists');
+			}
 		} catch (err) {
 			console.error(err);
 		} finally {

packages/integrations/netlify/test/edge-functions/edge-basic.test.ts

@@ -3,30 +3,34 @@ import { assertEquals, assert, DOMParser } from './deps.ts';
 
 Deno.env.set('SECRET_STUFF', 'secret');
 
-// @ts-expect-error
 Deno.test({
-	// TODO: debug why build cannot be found in "await import"
 	ignore: true,
 	name: 'Edge Basics',
-	skip: true,
-	async fn() {
+	permissions: 'inherit',
+	async fn(t) {
 		const fixture = loadFixture('./fixtures/edge-basic/');
-		await fixture.runBuild();
-		const { default: handler } = await import(
-			'./fixtures/edge-basic/.netlify/edge-functions/entry.js'
-		);
-		const response = await handler(new Request('http://example.com/'));
-		assertEquals(response.status, 200);
-		const html = await response.text();
-		assert(html, 'got some html');
+		await t.step('Run the build', async () => {
+			await fixture.runBuild();
+		});
+		await t.step('Should correctly render the response', async () => {
+			const { default: handler } = await import(
+				'./fixtures/edge-basic/.netlify/edge-functions/entry.js'
+			);
+			const response = await handler(new Request('http://example.com/'));
+			assertEquals(response.status, 200);
+			const html = await response.text();
+			assert(html, 'got some html');
 
-		const doc = new DOMParser().parseFromString(html, `text/html`)!;
-		const div = doc.querySelector('#react');
-		assert(div, 'div exists');
+			const doc = new DOMParser().parseFromString(html, `text/html`)!;
+			const div = doc.querySelector('#react');
+			assert(div, 'div exists');
 
-		const envDiv = doc.querySelector('#env');
-		assertEquals(envDiv?.innerText, 'secret');
+			const envDiv = doc.querySelector('#env');
+			assertEquals(envDiv?.innerText, 'secret');
+		});
 
-		await fixture.cleanup();
+		await t.step('Clean up', async () => {
+			await fixture.cleanup();
+		});
 	},
 });

packages/integrations/netlify/test/edge-functions/fixtures/edge-basic/astro.config.mjs

@@ -1,6 +1,5 @@
 import { defineConfig } from 'astro/config';
 import { netlifyEdgeFunctions } from '@astrojs/netlify';
-import react from "@astrojs/react";
 
 // test env var
 process.env.SECRET_STUFF = 'secret'
@@ -9,6 +8,5 @@ export default defineConfig({
 	adapter: netlifyEdgeFunctions({
 		dist: new URL('./dist/', import.meta.url),
 	}),
-	integrations: [react()],
 	output: 'server',
 })

packages/integrations/netlify/test/edge-functions/fixtures/edge-basic/package.json

@@ -5,8 +5,6 @@
   "dependencies": {
     "astro": "workspace:*",
     "@astrojs/react": "workspace:*",
-    "@astrojs/netlify": "workspace:*",
-    "react": "^18.1.0",
-    "react-dom": "^18.1.0"
+    "@astrojs/netlify": "workspace:*"
   }
 }

packages/integrations/netlify/test/edge-functions/fixtures/edge-basic/src/components/React.jsx

@@ -1,7 +0,0 @@
-import React from 'react';
-
-export default function() {
-	return (
-		<div id="react">testing</div>
-	)
-}

packages/integrations/netlify/test/edge-functions/fixtures/edge-basic/src/pages/index.astro

@@ -1,6 +1,3 @@
----
-import ReactComponent from '../components/React.jsx';
----
 <html>
 <head><title>Testing</title></head>
 <body>
@@ -9,7 +6,6 @@ import ReactComponent from '../components/React.jsx';
 	<ul>
 		<li><a href="/two/">Two</a></li>
 	</ul>
-	<ReactComponent />
 	<div id="env">{import.meta.env.SECRET_STUFF}</div>
 </body>
 </html>

packages/integrations/netlify/test/edge-functions/prerender.test.ts

@@ -3,12 +3,16 @@ import { assertEquals, assertExists, cheerio, fs } from './deps.ts';
 
 Deno.test({
 	name: 'Prerender',
+	permissions: 'inherit',
 	async fn(t) {
 		const environmentVariables = {
 			PRERENDER: 'true',
 		};
-		const fixture = loadFixture('./fixtures/prerender/', environmentVariables);
-		await fixture.runBuild();
+		const { runBuild, cleanup } = loadFixture('./fixtures/prerender/', environmentVariables);
+
+		await t.step('Run the build', async () => {
+			await runBuild();
+		});
 
 		await t.step('Handler can process requests to non-existing routes', async () => {
 			const { default: handler } = await import(
@@ -16,7 +20,7 @@ Deno.test({
 			);
 			assertExists(handler);
 			const response = await handler(new Request('http://example.com/index.html'));
-			assertEquals(response, undefined, "No response because this route doesn't exist");
+			assertEquals(response.status, 404, "No response because this route doesn't exist");
 		});
 
 		await t.step('Prerendered route exists', async () => {
@@ -31,22 +35,28 @@ Deno.test({
 		});
 
 		Deno.env.delete('PRERENDER');
-		await fixture.cleanup();
+		await cleanup();
 	},
 });
 
 Deno.test({
 	name: 'Hybrid rendering',
+	permissions: 'inherit',
 	async fn(t) {
 		const environmentVariables = {
 			PRERENDER: 'false',
 		};
 		const fixture = loadFixture('./fixtures/prerender/', environmentVariables);
-		await fixture.runBuild();
+		await t.step('Run the build', async () => {
+			await fixture.runBuild();
+		});
 
 		const stop = await fixture.runApp('./fixtures/prerender/prod.js');
 		await t.step('Can fetch server route', async () => {
-			const response = await fetch('http://127.0.0.1:8085/');
+			const { default: handler } = await import(
+				'./fixtures/prerender/.netlify/edge-functions/entry.js'
+			);
+			const response = await handler(new Request('http://example.com/'));
 			assertEquals(response.status, 200);
 
 			const html = await response.text();
@@ -60,7 +70,7 @@ Deno.test({
 				'./fixtures/prerender/.netlify/edge-functions/entry.js'
 			);
 			const response = await handler(new Request('http://example.com/index.html'));
-			assertEquals(response, undefined, "No response because this route doesn't exist");
+			assertEquals(response.status, 404, "No response because this route doesn't exist");
 		});
 
 		await t.step('Has no prerendered route', async () => {

packages/integrations/netlify/test/functions/edge-middleware.test.js

@@ -0,0 +1,43 @@
+import netlifyAdapter from '../../dist/index.js';
+import { testIntegration, loadFixture } from './test-utils.js';
+import { expect } from 'chai';
+
+describe('Middleware', () => {
+	it('with edge handle file, should successfully build the middleware', async () => {
+		/** @type {import('./test-utils').Fixture} */
+		const fixture = await loadFixture({
+			root: new URL('./fixtures/middleware-with-handler-file/', import.meta.url).toString(),
+			output: 'server',
+			adapter: netlifyAdapter({
+				dist: new URL('./fixtures/middleware-with-handler-file/dist/', import.meta.url),
+			}),
+			site: `http://example.com`,
+			integrations: [testIntegration()],
+			build: {
+				excludeMiddleware: true,
+			},
+		});
+		await fixture.build();
+		const contents = await fixture.readFile('../.netlify/edge-functions/edgeMiddleware.js');
+		expect(contents.includes('"Hello world"')).to.be.true;
+	});
+
+	it('without edge handle file, should successfully build the middleware', async () => {
+		/** @type {import('./test-utils').Fixture} */
+		const fixture = await loadFixture({
+			root: new URL('./fixtures/middleware-without-handler-file/', import.meta.url).toString(),
+			output: 'server',
+			adapter: netlifyAdapter({
+				dist: new URL('./fixtures/middleware-without-handler-file/dist/', import.meta.url),
+			}),
+			site: `http://example.com`,
+			integrations: [testIntegration()],
+			build: {
+				excludeMiddleware: true,
+			},
+		});
+		await fixture.build();
+		const contents = await fixture.readFile('../.netlify/edge-functions/edgeMiddleware.js');
+		expect(contents.includes('"Hello world"')).to.be.false;
+	});
+});

packages/integrations/netlify/test/functions/fixtures/middleware-with-handler-file/src/middleware.ts

@@ -0,0 +1,5 @@
+export const onRequest = (context, next) => {
+	context.locals.title = 'Middleware';
+
+	return next();
+};

packages/integrations/netlify/test/functions/fixtures/middleware-with-handler-file/src/netlify-edge-middleware.js

@@ -0,0 +1,5 @@
+export default function ({ request, context }) {
+	return {
+		title: 'Hello world',
+	};
+}

packages/integrations/netlify/test/functions/fixtures/middleware-with-handler-file/src/pages/index.astro

@@ -0,0 +1,12 @@
+---
+const title = Astro.locals.title;
+---
+
+<html>
+<head>
+    <title>{title}</title>
+</head>
+<body>
+<h1>{title}</h1>
+</body>
+</html>

packages/integrations/netlify/test/functions/fixtures/middleware-without-handler-file/src/middleware.ts

@@ -0,0 +1,5 @@
+export const onRequest = (context, next) => {
+	context.locals.title = 'Middleware';
+
+	return next();
+};

packages/integrations/netlify/test/functions/fixtures/middleware-without-handler-file/src/pages/index.astro

@@ -0,0 +1,12 @@
+---
+const title = Astro.locals.title;
+---
+
+<html>
+<head>
+    <title>{title}</title>
+</head>
+<body>
+<h1>{title}</h1>
+</body>
+</html>

packages/integrations/netlify/tsconfig.json

@@ -6,6 +6,7 @@
     "module": "ES2022",
     "outDir": "./dist",
     "target": "ES2021",
-    "typeRoots": ["node_modules/@types", "node_modules/@netlify"]
+    "typeRoots": ["node_modules/@types", "node_modules/@netlify"],
+    "allowImportingTsExtensions": true
   }
 }

pnpm-lock.yaml

@@ -4464,12 +4464,6 @@ importers:
       astro:
         specifier: workspace:*
         version: link:../../../../../../astro
-      react:
-        specifier: ^18.1.0
-        version: 18.2.0
-      react-dom:
-        specifier: ^18.1.0
-        version: 18.2.0(react@18.2.0)
 
   packages/integrations/netlify/test/edge-functions/fixtures/prerender:
     dependencies: