feat: vercel edge middleware support (#7532)

Co-authored-by: Bjorn Lu <bjornlu.dev@gmail.com>
Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>

1 files changed, 30 insertions, 5 deletions

diff --git a/packages/integrations/vercel/src/serverless/adapter.ts b/packages/integrations/vercel/src/serverless/adapter.ts
index 007fb8537..9d799a7bf 100644
--- a/packages/integrations/vercel/src/serverless/adapter.ts
+++ b/packages/integrations/vercel/src/serverless/adapter.ts
@@ -13,8 +13,12 @@ import { exposeEnv } from '../lib/env.js';
 import { getVercelOutput, removeDir, writeJson } from '../lib/fs.js';
 import { copyDependenciesToFunction } from '../lib/nft.js';
 import { getRedirects } from '../lib/redirects.js';
+import { generateEdgeMiddleware } from './middleware.js';
+import { fileURLToPath } from 'node:url';
 
 const PACKAGE_NAME = '@astrojs/vercel/serverless';
+export const ASTRO_LOCALS_HEADER = 'x-astro-locals';
+export const VERCEL_EDGE_MIDDLEWARE_FILE = 'vercel-edge-middleware';
 
 function getAdapter(): AstroAdapter {
 	return {
@@ -70,6 +74,8 @@ export default function vercelServerless({
 		});
 	}
 
+	const filesToInclude = includeFiles?.map((file) => new URL(file, _config.root)) || [];
+
 	return {
 		name: PACKAGE_NAME,
 		hooks: {
@@ -106,17 +112,32 @@ export default function vercelServerless({
 	`);
 				}
 			},
-			'astro:build:ssr': async ({ entryPoints }) => {
+
+			'astro:build:ssr': async ({ entryPoints, middlewareEntryPoint }) => {
 				_entryPoints = entryPoints;
+				if (middlewareEntryPoint) {
+					const outPath = fileURLToPath(buildTempFolder);
+					const vercelEdgeMiddlewareHandlerPath = new URL(
+						VERCEL_EDGE_MIDDLEWARE_FILE,
+						_config.srcDir
+					);
+					const bundledMiddlewarePath = await generateEdgeMiddleware(
+						middlewareEntryPoint,
+						outPath,
+						vercelEdgeMiddlewareHandlerPath
+					);
+					// let's tell the adapter that we need to save this file
+					filesToInclude.push(bundledMiddlewarePath);
+				}
 			},
+
 			'astro:build:done': async ({ routes }) => {
 				// Merge any includes from `vite.assetsInclude
-				const inc = includeFiles?.map((file) => new URL(file, _config.root)) || [];
 				if (_config.vite.assetsInclude) {
 					const mergeGlobbedIncludes = (globPattern: unknown) => {
 						if (typeof globPattern === 'string') {
 							const entries = glob.sync(globPattern).map((p) => pathToFileURL(p));
-							inc.push(...entries);
+							filesToInclude.push(...entries);
 						} else if (Array.isArray(globPattern)) {
 							for (const pattern of globPattern) {
 								mergeGlobbedIncludes(pattern);
@@ -133,14 +154,18 @@ export default function vercelServerless({
 				if (_entryPoints.size) {
 					for (const [route, entryFile] of _entryPoints) {
 						const func = basename(entryFile.toString()).replace(/\.mjs$/, '');
-						await createFunctionFolder(func, entryFile, inc);
+						await createFunctionFolder(func, entryFile, filesToInclude);
 						routeDefinitions.push({
 							src: route.pattern.source,
 							dest: func,
 						});
 					}
 				} else {
-					await createFunctionFolder('render', new URL(serverEntry, buildTempFolder), inc);
+					await createFunctionFolder(
+						'render',
+						new URL(serverEntry, buildTempFolder),
+						filesToInclude
+					);
 					routeDefinitions.push({ src: '/.*', dest: 'render' });
 				}