[feat] allow node adapter to configure listen path (#2048)

Author: matths

.changeset/eighty-waves-obey.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/adapter-node': patch
+---
+
+[feat] allow node adapter to configure listen path

packages/adapter-node/index.js

@@ -25,6 +25,7 @@ const pipe = promisify(pipeline);
  *   out?: string;
  *   precompress?: boolean;
  *   env?: {
+ *     path?: string;
  *     host?: string;
  *     port?: string;
  *   };
@@ -34,7 +35,7 @@ const pipe = promisify(pipeline);
 export default function ({
 	out = 'build',
 	precompress,
-	env: { host: host_env = 'HOST', port: port_env = 'PORT' } = {},
+	env: { path: path_env = 'SOCKET_PATH', host: host_env = 'HOST', port: port_env = 'PORT' } = {},
 	esbuild: esbuildConfig
 } = {}) {
 	/** @type {import('@sveltejs/kit').Adapter} */
@@ -57,7 +58,9 @@ export default function ({
 			utils.copy(files, '.svelte-kit/node');
 			writeFileSync(
 				'.svelte-kit/node/env.js',
-				`export const host = process.env[${JSON.stringify(
+				`export const path = process.env[${JSON.stringify(
+					path_env
+				)}] || false;\nexport const host = process.env[${JSON.stringify(
 					host_env
 				)}] || '0.0.0.0';\nexport const port = process.env[${JSON.stringify(port_env)}] || 3000;`
 			);

packages/adapter-node/src/index.js

@@ -1,12 +1,15 @@
 // TODO hardcoding the relative location makes this brittle
 import { init, render } from '../output/server/app.js'; // eslint-disable-line import/no-unresolved
-import { host, port } from './env.js'; // eslint-disable-line import/no-unresolved
+import { path, host, port } from './env.js'; // eslint-disable-line import/no-unresolved
 import { createServer } from './server';
 
 init();
 
-const instance = createServer({ render }).listen(port, host, () => {
-	console.log(`Listening on ${host}:${port}`);
+const instance = createServer({ render });
+
+const listenOpts = { path, host, port };
+instance.listen(listenOpts, () => {
+	console.log(`Listening on ${path ? path : host + ':' + port}`);
 });
 
 export { instance };