[fix] preserve user defined config and files on svelte-kit package

.changeset/unlucky-planets-battle.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+Preserve README casing and package.json contents on svelte-kit package

documentation/docs/12-packaging.md

@@ -12,7 +12,7 @@ Running `svelte-kit package` will take the contents of `src/lib` and generate a
 
 - All the files in `src/lib`, unless you [configure](#configuration-package) custom `include`/`exclude` options. Svelte components will be preprocessed, TypeScript files will be transpiled to JavaScript.
 - Type definitions (`d.ts` files) which are generated for Svelte, JavaScript and TypeScript files. You need to install `typescript >= 4.0.0` and `svelte2tsx >= 0.4.1` for this. Type definitions are placed next to their implementation, hand-written `d.ts` files are copied over as is.
-- A `package.json` that copies the `name`, `version`, `description`, `keywords`, `homepage`, `bugs`, `license`, `author`, `contributors`, `funding`, `repository`, `dependencies`, `private` and `publishConfig` fields from the root of the project, and adds a `"type": "module"` and an `"exports"` field
+- A `package.json` copied from the project root without the `"scripts"` field and adds a `"type": "module"`. An `"exports"` field will also be added if it's not defined in the original file.
 
 The `"exports"` field contains the package's entry points. By default, all files in `src/lib` will be treated as an entry point unless they start with (or live in a directory that starts with) an underscore, but you can [configure](#configuration-package) this behaviour. If you have a `src/lib/index.js` or `src/lib/index.svelte` file, it will be treated as the package root.
 

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

@@ -25,27 +25,16 @@ export async function make_package(config, cwd = process.cwd()) {
 
 	const pkg = JSON.parse(fs.readFileSync(path.join(cwd, 'package.json'), 'utf8'));
 
-	const package_pkg = {
-		name: pkg.name,
-		version: pkg.version,
-		description: pkg.description,
-		keywords: pkg.keywords,
-		homepage: pkg.homepage,
-		bugs: pkg.bugs,
-		license: pkg.license,
-		author: pkg.author,
-		contributors: pkg.contributors,
-		funding: pkg.funding,
-		repository: pkg.repository,
-		dependencies: pkg.dependencies,
-		private: pkg.private,
-		publishConfig: pkg.publishConfig,
-		type: 'module',
-		/** @type {Record<string, string>} */
-		exports: {
+	delete pkg.scripts;
+	pkg.type = 'module'; // type must be 'module'
+
+	let user_defined_exports = true;
+	if (!('exports' in pkg)) {
+		user_defined_exports = false;
+		pkg.exports = {
 			'./package.json': './package.json'
-		}
-	};
+		};
+	}
 
 	for (const file of files) {
 		if (!files_filter(file)) continue;
@@ -89,27 +78,27 @@ export async function make_package(config, cwd = process.cwd()) {
 
 		write(path.join(cwd, config.kit.package.dir, out_file), out_contents);
 
-		if (exports_filter(file)) {
-			const entry = `./${out_file}`;
-			package_pkg.exports[entry] = entry;
+		if (!user_defined_exports && exports_filter(file)) {
+			const entry = `./${out_file.replace(/\\/g, '/')}`;
+			pkg.exports[entry] = entry;
 		}
 	}
 
-	const main = package_pkg.exports['./index.js'] || package_pkg.exports['./index.svelte'];
+	const main = pkg.exports['./index.js'] || pkg.exports['./index.svelte'];
 
-	if (main) {
-		package_pkg.exports['.'] = main;
+	if (!user_defined_exports && main) {
+		pkg.exports['.'] = main;
 	}
 
-	write(
-		path.join(cwd, config.kit.package.dir, 'package.json'),
-		JSON.stringify(package_pkg, null, '  ')
-	);
+	write(path.join(cwd, config.kit.package.dir, 'package.json'), JSON.stringify(pkg, null, '  '));
 
 	const project_readme = path.join(cwd, 'README.md');
-	const package_readme = path.join(cwd, config.kit.package.dir, 'README.md');
+	const readme_exists = fs.existsSync(project_readme);
+	if (!readme_exists) return;
 
-	if (fs.existsSync(project_readme) && !fs.existsSync(package_readme)) {
+	const preserved_filename = fs.realpathSync.native(project_readme).slice(-'README.md'.length);
+	const package_readme = path.join(cwd, config.kit.package.dir, preserved_filename);
+	if (!fs.existsSync(package_readme)) {
 		fs.copyFileSync(project_readme, package_readme);
 	}
 }