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, 53 insertions, 0 deletions

diff --git a/packages/integrations/node/src/middleware.ts b/packages/integrations/node/src/middleware.ts
new file mode 100644
index 000000000..772461f2a
--- /dev/null
+++ b/packages/integrations/node/src/middleware.ts
@@ -0,0 +1,53 @@
+import type { NodeApp } from 'astro/app/node';
+import type { IncomingMessage, ServerResponse } from 'http';
+import type { Readable } from 'stream';
+
+export default function(app: NodeApp) {
+	return async function(req: IncomingMessage, res: ServerResponse, next?: (err?: unknown) => void) {
+		try {
+			const route = app.match(req);
+
+			if (route) {
+				try {
+					const response = await app.render(req);
+					await writeWebResponse(app, res, response);
+				} catch (err: unknown) {
+					if (next) {
+						next(err);
+					} else {
+						throw err;
+					}
+				}
+			} else if (next) {
+				return next();
+			} else {
+				res.writeHead(404);
+				res.end('Not found');
+			}
+		} catch (err: unknown) {
+			if (!res.headersSent) {
+				res.writeHead(500, `Server error`);
+				res.end();
+			}
+		}
+	};
+}
+
+async function writeWebResponse(app: NodeApp, res: ServerResponse, webResponse: Response) {
+	const { status, headers, body } = webResponse;
+
+	if (app.setCookieHeaders) {
+		const setCookieHeaders: Array<string> = Array.from(app.setCookieHeaders(webResponse));
+		if (setCookieHeaders.length) {
+			res.setHeader('Set-Cookie', setCookieHeaders);
+		}
+	}
+
+	res.writeHead(status, Object.fromEntries(headers.entries()));
+	if (body) {
+		for await (const chunk of body as unknown as Readable) {
+			res.write(chunk);
+		}
+	}
+	res.end();
+}