feat(adpater-node): support all esbuild build options

This PR allows to change the options passed to esbuild build which allows  to customize the server generation like target node version, sourcemap, inject and more.

It contains one braking change: `out` is renamed to `outdir` to follow the esbuild API. It is possible to avoid a breaking change by making `out` an alias for `outdir`. I'm happy to adjust the PR.

Author: sastan

.changeset/stale-books-flash.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/adapter-node': patch
+---
+
+support all esbuild build options

packages/adapter-node/README.md

@@ -13,18 +13,24 @@ import adapter from '@sveltejs/adapter-node';
 export default {
 	kit: {
 		adapter: adapter({
-			// default options are shown
-			out: 'build'
+			// default options are shown below
+			outdir: 'build',
+			outfile: join(outdir, 'index.js')
+			bundle: true,
+			format: 'esm',
+			platform: 'node',
+			target: 'node12',
+			external: Object.keys(JSON.parse(readFileSync('package.json', 'utf8')).dependencies || {}),
 		})
 	}
 };
 ```
 
 ## Options
 
-### out
+All [esbuild build](https://esbuild.github.io/api/#build-api) options except for `entryPoints` are supported.
 
-The directory to build the server to. It defaults to `build` — i.e. `node build` would start the server locally after it has been created.
+The [outdir](https://esbuild.github.io/api/#outdir) is the directory to build the server to. It defaults to `build` — i.e. `node build` would start the server locally after it has been created.
 
 ## Environment variables
 

packages/adapter-node/index.d.ts

@@ -1,3 +1,3 @@
-declare function plugin(options?: { out?: string }): import('@sveltejs/kit').Adapter;
+declare function plugin(options?: import('esbuild').BuildOptions): import('@sveltejs/kit').Adapter;
 
 export = plugin;

packages/adapter-node/index.js

@@ -4,40 +4,50 @@ import { join } from 'path';
 import { fileURLToPath } from 'url';
 
 /**
- * @param {{
- *   out?: string;
- * }} options
+ * @param {import('esbuild').BuildOptions} options
  */
-export default function ({ out = 'build' } = {}) {
+export default function ({
+	outdir = 'build',
+	outfile = join(outdir, 'index.js'),
+	bundle = true,
+	format = 'esm',
+	platform = 'node',
+	target = 'node12',
+	external = Object.keys(JSON.parse(readFileSync('package.json', 'utf8')).dependencies || {}),
+	...esbuildOptions
+} = {}) {
 	/** @type {import('@sveltejs/kit').Adapter} */
 	const adapter = {
 		name: '@sveltejs/adapter-node',
 
 		async adapt({ utils, config }) {
 			utils.log.minor('Copying assets');
-			const static_directory = join(out, 'assets');
+			const static_directory = join(outdir, 'assets');
 			utils.copy_client_files(static_directory);
 			utils.copy_static_files(static_directory);
 
 			utils.log.minor('Building server');
 			const files = fileURLToPath(new URL('./files', import.meta.url));
 			utils.copy(files, '.svelte-kit/node');
 			await esbuild.build({
+				...esbuildOptions,
+				outdir,
+				outfile,
+				bundle,
+				format,
+				platform,
+				target,
+				external,
 				entryPoints: ['.svelte-kit/node/index.js'],
-				outfile: join(out, 'index.js'),
-				bundle: true,
-				external: Object.keys(JSON.parse(readFileSync('package.json', 'utf8')).dependencies || {}),
-				format: 'esm',
-				platform: 'node',
-				target: 'node12',
 				define: {
+					...esbuildOptions.define,
 					esbuild_app_dir: '"' + config.kit.appDir + '"'
 				}
 			});
 
 			utils.log.minor('Prerendering static pages');
 			await utils.prerender({
-				dest: `${out}/prerendered`
+				dest: `${outdir}/prerendered`
 			});
 		}
 	};