Node.js standalone mode + support for astro preview (#5056)

* wip

* Deprecate buildConfig and move to config.build

* Implement the standalone server

* Stay backwards compat

* Add changesets

* correctly merge URLs

* Get config earlier

* update node tests

* Return the preview server

* update remaining tests

* swap usage and config ordering

* Update packages/astro/src/@types/astro.ts

Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>

* Update .changeset/metal-pumas-walk.md

Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>

* Update .changeset/metal-pumas-walk.md

Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>

* Update .changeset/stupid-points-refuse.md

Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>

* Update .changeset/stupid-points-refuse.md

Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>

* Link to build.server config

Co-authored-by: Fred K. Schott <fkschott@gmail.com>
Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>

1 files changed, 54 insertions, 0 deletions

diff --git a/packages/integrations/node/src/preview.ts b/packages/integrations/node/src/preview.ts
new file mode 100644
index 000000000..33c2f18e2
--- /dev/null
+++ b/packages/integrations/node/src/preview.ts
@@ -0,0 +1,54 @@
+import type { CreatePreviewServer } from 'astro';
+import type { createExports } from './server';
+import http from 'http';
+import { fileURLToPath } from 'url';
+import { createServer } from './http-server.js';
+
+const preview: CreatePreviewServer = async function({
+	client,
+	serverEntrypoint,
+	host,
+	port,
+}) {
+	type ServerModule = ReturnType<typeof createExports>;
+	type MaybeServerModule = Partial<ServerModule>;
+	let ssrHandler: ServerModule['handler'];
+	try {
+		process.env.ASTRO_NODE_AUTOSTART = 'disabled';
+		const ssrModule: MaybeServerModule = await import(serverEntrypoint.toString());
+		if(typeof ssrModule.handler === 'function') {
+			ssrHandler = ssrModule.handler;
+		} else {
+			throw new Error(`The server entrypoint doesn't have a handler. Are you sure this is the right file?`);
+		}
+	} catch(_err) {
+		throw new Error(`The server entrypoint ${fileURLToPath} does not exist. Have you ran a build yet?`);
+	}
+
+	const handler: http.RequestListener = (req, res) => {
+		ssrHandler(req, res, (ssrErr: any) => {
+			if (ssrErr) {
+				res.writeHead(500);
+				res.end(ssrErr.toString());
+			} else {
+				res.writeHead(404);
+				res.end();
+			}
+		});
+	};
+
+	const server = createServer({
+		client,
+		port,
+		host,
+	}, handler);
+
+	// eslint-disable-next-line no-console
+	console.log(`Preview server listening on http://${host}:${port}`);
+
+	return server;
+}
+
+export {
+	preview as default
+};