1 files changed, 78 insertions, 0 deletions
diff --git a/packages/integrations/vercel/src/serverless/adapter.ts b/packages/integrations/vercel/src/serverless/adapter.ts
new file mode 100644
index 000000000..babda1f84
--- /dev/null
+++ b/packages/integrations/vercel/src/serverless/adapter.ts
@@ -0,0 +1,78 @@
+import type { AstroAdapter, AstroConfig, AstroIntegration } from 'astro';
+
+import { writeJson, getVercelOutput } from '../lib/fs.js';
+import { copyDependenciesToFunction } from '../lib/nft.js';
+import { getRedirects } from '../lib/redirects.js';
+
+const PACKAGE_NAME = '@astrojs/vercel/serverless';
+
+function getAdapter(): AstroAdapter {
+	return {
+		name: PACKAGE_NAME,
+		serverEntrypoint: `${PACKAGE_NAME}/entrypoint`,
+		exports: ['default'],
+	};
+}
+
+export interface Options {
+	nodeVersion?: '12.x' | '14.x' | '16.x';
+}
+
+export default function vercelEdge({ nodeVersion = '16.x' }: Options = {}): AstroIntegration {
+	let _config: AstroConfig;
+	let functionFolder: URL;
+	let serverEntry: string;
+
+	return {
+		name: PACKAGE_NAME,
+		hooks: {
+			'astro:config:setup': ({ config }) => {
+				config.outDir = getVercelOutput(config.root);
+			},
+			'astro:config:done': ({ setAdapter, config }) => {
+				setAdapter(getAdapter());
+				_config = config;
+			},
+			'astro:build:start': async ({ buildConfig }) => {
+				if (String(process.env.ENABLE_VC_BUILD) !== '1') {
+					throw new Error(
+						`The enviroment variable "ENABLE_VC_BUILD" was not found. Make sure you have it set to "1" in your Vercel project.\nLearn how to set enviroment variables here: https://vercel.com/docs/concepts/projects/environment-variables`
+					);
+				}
+
+				buildConfig.serverEntry = serverEntry = 'entry.js';
+				buildConfig.client = new URL('./static/', _config.outDir);
+				buildConfig.server = functionFolder = new URL('./functions/render.func/', _config.outDir);
+			},
+			'astro:build:done': async ({ routes }) => {
+				// Copy necessary files (e.g. node_modules/)
+				await copyDependenciesToFunction(_config.root, functionFolder, serverEntry);
+
+				// Enable ESM
+				// https://aws.amazon.com/blogs/compute/using-node-js-es-modules-and-top-level-await-in-aws-lambda/
+				await writeJson(new URL(`./package.json`, functionFolder), {
+					type: 'module',
+				});
+
+				// Serverless function config
+				// https://vercel.com/docs/build-output-api/v3#vercel-primitives/serverless-functions/configuration
+				await writeJson(new URL(`./.vc-config.json`, functionFolder), {
+					runtime: `nodejs${nodeVersion}`,
+					handler: serverEntry,
+					launcherType: 'Nodejs',
+				});
+
+				// Output configuration
+				// https://vercel.com/docs/build-output-api/v3#build-output-configuration
+				await writeJson(new URL(`./config.json`, _config.outDir), {
+					version: 3,
+					routes: [
+						...getRedirects(routes, _config),
+						{ handle: 'filesystem' },
+						{ src: '/.*', dest: 'render' },
+					],
+				});
+			},
+		},
+	};
+}