Make build folder of adapter-node self-sufficient

packages/adapter-node/index.js

@@ -1,4 +1,4 @@
-import { readFileSync, writeFileSync } from 'fs';
+import { writeFileSync } from 'fs';
 import { fileURLToPath } from 'url';
 import * as esbuild from 'esbuild';
 
@@ -45,7 +45,10 @@ export default function (opts = {}) {
 				`export const manifest = ${builder.generateManifest({ relativePath: './' })};`
 			);
 
-			const pkg = JSON.parse(readFileSync('package.json', 'utf8'));
+			const optimized_package_json = builder.generatePackageJson();
+			writeFileSync(`${out}/package.json`, optimized_package_json);
+
+			const pkg = JSON.parse(optimized_package_json);
 
 			await esbuild.build({
 				platform: 'node',

packages/kit/src/core/adapt/builder.js

@@ -5,6 +5,7 @@ import { pipeline } from 'stream';
 import { promisify } from 'util';
 import { copy, rimraf, mkdirp } from '../../utils/filesystem.js';
 import { generate_manifest } from '../generate_manifest/index.js';
+import { generate_package_json } from '../generate_package_json/index.js';
 
 const pipe = promisify(pipeline);
 
@@ -113,6 +114,13 @@ export function create_builder({ config, build_data, routes, prerendered, log })
 			});
 		},
 
+		generatePackageJson: () => {
+			return generate_package_json({
+				build_data,
+				cwd: process.cwd()
+			});
+		},
+
 		getBuildDirectory(name) {
 			return `${config.kit.outDir}/${name}`;
 		},

packages/kit/src/core/generate_package_json/index.js

@@ -0,0 +1,79 @@
+import fs from 'node:fs';
+import path from 'node:path';
+
+/**
+ * Generates a production package.json
+ * @param {{
+ *   build_data: import('types').BuildData;
+ *   cwd: string;
+ * }} opts
+ */
+export function generate_package_json({ build_data, cwd }) {
+	const package_json_text = fs.readFileSync(path.resolve(cwd, 'package.json'), 'utf8');
+	const package_json = JSON.parse(package_json_text);
+	const dependences_with_versions = Object.assign(
+		{},
+		package_json.devDependencies || {},
+		package_json.dependencies || {}
+	);
+
+	const dependencies = Object.keys(dependences_with_versions);
+
+	/** @type {Set<string>} */
+	const dependencies_set = new Set(dependencies);
+
+	const prod_package_json = Object.assign({}, package_json);
+	delete prod_package_json.devDependencies;
+	delete prod_package_json.scripts;
+	prod_package_json.dependencies = {};
+
+	const chunks = [build_data.client.chunks, build_data.server.chunks].flat();
+	if (chunks.length > 0) {
+		/** @type {string[]} */
+		const dependency_names = filter_import_packages(chunks, dependencies_set);
+		dependency_names.sort();
+		prod_package_json.dependencies = create_dependency_object(
+			dependency_names,
+			dependences_with_versions
+		);
+	}
+
+	return JSON.stringify(prod_package_json, null, 2);
+}
+/**
+ *
+ * @param {import('rollup').OutputChunk[]} chunks
+ * @param {Set<string>} dependencies_set
+ */
+function filter_import_packages(chunks, dependencies_set) {
+	/** @type {string[]} */
+	const import_names = chunks.reduce((/** @type {string[]} */ deps, chunk) => {
+		if (chunk.imports.length > 0) {
+			for (let i = 0; i < chunk.imports.length; i++) {
+				const importName = chunk.imports[i];
+				if (dependencies_set.has(importName)) {
+					deps.push(importName);
+				}
+			}
+		}
+
+		return deps;
+	}, []);
+
+	return import_names;
+}
+
+/**
+ *
+ * @param {string[]} dependency_names
+ * @param {{[key: string]: string}} dependences_with_versions
+ */
+function create_dependency_object(dependency_names, dependences_with_versions) {
+	/** @type {{[key: string]: string}} */
+	const dependencies = {};
+	for (let i = 0; i < dependency_names.length; i++) {
+		dependencies[dependency_names[i]] = dependences_with_versions[dependency_names[i]];
+	}
+
+	return dependencies;
+}

packages/kit/src/exports/vite/index.js

@@ -17,6 +17,7 @@ import { preview } from './preview/index.js';
 import { get_aliases, resolve_entry, prevent_illegal_rollup_imports, get_env } from './utils.js';
 import { fileURLToPath } from 'node:url';
 import { create_static_module, create_dynamic_module } from '../../core/env.js';
+import { generate_package_json } from '../../core/generate_package_json/index.js';
 
 const cwd = process.cwd();
 
@@ -404,6 +405,15 @@ function kit() {
 					})};\n`
 				);
 
+				const package_json_path = `${paths.output_dir}/package.json`;
+				fs.writeFileSync(
+					package_json_path,
+					generate_package_json({
+						build_data,
+						cwd
+					})
+				);
+
 				log.info('Prerendering');
 				await new Promise((fulfil, reject) => {
 					const results_path = `${svelte_config.kit.outDir}/generated/prerendered.json`;

packages/kit/types/index.d.ts

@@ -56,6 +56,7 @@ export interface Builder {
 	createEntries(fn: (route: RouteDefinition) => AdapterEntry): Promise<void>;
 
 	generateManifest: (opts: { relativePath: string; format?: 'esm' | 'cjs' }) => string;
+	generatePackageJson: () => string;
 
 	getBuildDirectory(name: string): string;
 	getClientDirectory(): string;