feat: support specifying the tsconfig in svelte-package

.changeset/clean-dots-switch.md

@@ -0,0 +1,5 @@
+---
+"@sveltejs/package": minor
+---
+
+feat: add option to specify the tsconfig/jsconfig

documentation/docs/30-advanced/70-packaging.md

@@ -197,6 +197,7 @@ You should think carefully about whether or not the changes you make to your pac
 - `-i`/`--input` — the input directory which contains all the files of the package. Defaults to `src/lib`
 - `-o`/`--o` — the output directory where the processed files are written to. Your `package.json`'s `exports` should point to files inside there, and the `files` array should include that folder. Defaults to `dist`
 - `-t`/`--types` — whether or not to create type definitions (`d.ts` files). We strongly recommend doing this as it fosters ecosystem library quality. Defaults to `true`
+- `--tsconfig` - the path to a tsconfig or jsconfig. When not provided, searches for the next upper tsconfig/jsconfig in the workspace path.
 
 ## Publishing
 

packages/package/src/cli.js

@@ -24,6 +24,10 @@ prog
 	.option('-o, --output', 'Output directory', 'dist')
 	.option('-t, --types', 'Emit type declarations', true)
 	.option('-w, --watch', 'Rerun when files change', false)
+	.option(
+		'--tsconfig',
+		'A path to a tsconfig or jsconfig file. When not provided, searches for the next upper tsconfig/jsconfig in the workspace path.'
+	)
 	.action(async (args) => {
 		try {
 			const config = await load_config();
@@ -42,6 +46,7 @@ prog
 				cwd: process.cwd(),
 				input: args.input ?? config.kit?.files?.lib ?? 'src/lib',
 				output: args.output,
+				tsconfig: args.tsconfig,
 				types: args.types,
 				config
 			};

packages/package/src/index.js

@@ -22,7 +22,7 @@ export async function build(options) {
  * @param {(name: string, code: string) => void} analyse_code
  */
 async function do_build(options, analyse_code) {
-	const { input, output, temp, extensions, alias } = normalize_options(options);
+	const { input, output, temp, extensions, alias, tsconfig } = normalize_options(options);
 
 	if (!fs.existsSync(input)) {
 		throw new Error(`${path.relative('.', input)} does not exist`);
@@ -38,7 +38,7 @@ async function do_build(options, analyse_code) {
 	}
 
 	for (const file of files) {
-		await process_file(input, temp, file, options.config.preprocess, alias, analyse_code);
+		await process_file(input, temp, file, options.config.preprocess, alias, tsconfig, analyse_code);
 	}
 
 	rimraf(output);
@@ -62,7 +62,7 @@ export async function watch(options) {
 
 	validate();
 
-	const { input, output, extensions, alias } = normalize_options(options);
+	const { input, output, extensions, alias, tsconfig } = normalize_options(options);
 
 	const message = `\nWatching ${path.relative(options.cwd, input)} for changes...\n`;
 
@@ -119,7 +119,15 @@ export async function watch(options) {
 				if (type === 'add' || type === 'change') {
 					console.log(`Processing ${file.name}`);
 					try {
-						await process_file(input, output, file, options.config.preprocess, alias, analyse_code);
+						await process_file(
+							input,
+							output,
+							file,
+							options.config.preprocess,
+							alias,
+							tsconfig,
+							analyse_code
+						);
 					} catch (e) {
 						errored = true;
 						console.error(e);
@@ -170,6 +178,7 @@ function normalize_options(options) {
 		'__package__'
 	);
 	const extensions = options.config.extensions ?? ['.svelte'];
+	const tsconfig = options.tsconfig ? path.resolve(options.cwd, options.tsconfig) : undefined;
 
 	const alias = {
 		$lib: path.resolve(options.cwd, options.config.kit?.files?.lib ?? 'src/lib'),
@@ -181,7 +190,8 @@ function normalize_options(options) {
 		output,
 		temp,
 		extensions,
-		alias
+		alias,
+		tsconfig
 	};
 }
 
@@ -191,9 +201,10 @@ function normalize_options(options) {
  * @param {import('./types.js').File} file
  * @param {import('svelte/types/compiler/preprocess').PreprocessorGroup | undefined} preprocessor
  * @param {Record<string, string>} aliases
+ * @param {string | undefined} tsconfig
  * @param {(name: string, code: string) => void} analyse_code
  */
-async function process_file(input, output, file, preprocessor, aliases, analyse_code) {
+async function process_file(input, output, file, preprocessor, aliases, tsconfig, analyse_code) {
 	const filename = path.join(input, file.name);
 	const dest = path.join(output, file.dest);
 
@@ -208,7 +219,7 @@ async function process_file(input, output, file, preprocessor, aliases, analyse_
 		}
 
 		if (file.name.endsWith('.ts') && !file.name.endsWith('.d.ts')) {
-			contents = await transpile_ts(filename, contents);
+			contents = await transpile_ts(tsconfig, filename, contents);
 		}
 
 		contents = resolve_aliases(input, file.name, contents, aliases);

packages/package/src/types.d.ts

@@ -5,6 +5,7 @@ export interface Options {
 	input: string;
 	output: string;
 	types: boolean;
+	tsconfig?: string;
 	config: {
 		extensions?: string[];
 		kit?: {

packages/package/src/typescript.js

@@ -62,12 +62,13 @@ export async function emit_dts(input, output, cwd, alias, files) {
 /**
  * TS -> JS
  *
+ * @param {string | undefined} tsconfig
  * @param {string} filename
  * @param {string} source
  */
-export async function transpile_ts(filename, source) {
+export async function transpile_ts(tsconfig, filename, source) {
 	const ts = await try_load_ts();
-	const options = load_tsconfig(filename, ts);
+	const options = load_tsconfig(tsconfig, filename, ts);
 	// transpileModule treats NodeNext as CommonJS because it doesn't read the package.json. Therefore we need to override it.
 	// Also see https://github.com/microsoft/TypeScript/issues/53022 (the filename workaround doesn't work).
 	return ts.transpileModule(source, {
@@ -91,28 +92,37 @@ async function try_load_ts() {
 }
 
 /**
+ * @param {string | undefined} tsconfig
  * @param {string} filename
  * @param {import('typescript')} ts
  */
-function load_tsconfig(filename, ts) {
+function load_tsconfig(tsconfig, filename, ts) {
 	let config_filename;
 
-	// ts.findConfigFile is broken (it will favour a distant tsconfig
-	// over a near jsconfig, and then only when you call it twice)
-	// so we implement it ourselves
-	let dir = filename;
-	while (dir !== (dir = path.dirname(dir))) {
-		const tsconfig = path.join(dir, 'tsconfig.json');
-		const jsconfig = path.join(dir, 'jsconfig.json');
-
+	if (tsconfig) {
 		if (fs.existsSync(tsconfig)) {
 			config_filename = tsconfig;
-			break;
+		} else {
+			throw new Error('Failed to locate provided tsconfig or jsconfig');
 		}
-
-		if (fs.existsSync(jsconfig)) {
-			config_filename = jsconfig;
-			break;
+	} else {
+		// ts.findConfigFile is broken (it will favour a distant tsconfig
+		// over a near jsconfig, and then only when you call it twice)
+		// so we implement it ourselves
+		let dir = filename;
+		while (dir !== (dir = path.dirname(dir))) {
+			const tsconfig = path.join(dir, 'tsconfig.json');
+			const jsconfig = path.join(dir, 'jsconfig.json');
+
+			if (fs.existsSync(tsconfig)) {
+				config_filename = tsconfig;
+				break;
+			}
+
+			if (fs.existsSync(jsconfig)) {
+				config_filename = jsconfig;
+				break;
+			}
 		}
 	}
 

packages/package/test/fixtures/tsconfig-specified/expected/runes.svelte.d.ts

@@ -0,0 +1 @@
+export declare const x = true;

packages/package/test/fixtures/tsconfig-specified/expected/runes.svelte.js

@@ -0,0 +1 @@
+export const x = true;

packages/package/test/fixtures/tsconfig-specified/package.json

@@ -0,0 +1,16 @@
+{
+	"name": "typescript",
+	"private": true,
+	"version": "1.0.0",
+	"description": "typescript package using esnext",
+	"type": "module",
+	"peerDependencies": {
+		"svelte": "^4.0.0"
+	},
+	"exports": {
+		".": {
+			"types": "./dist/index.d.ts",
+			"svelte": "./dist/index.js"
+		}
+	}
+}

packages/package/test/fixtures/tsconfig-specified/src/lib/runes.svelte.ts

@@ -0,0 +1,2 @@
+// a comment to delete
+export const x = true;

packages/package/test/fixtures/tsconfig-specified/svelte.config.js

@@ -0,0 +1,7 @@
+import preprocess from 'svelte-preprocess';
+
+export default {
+	preprocess: preprocess({
+		preserve: ['ld+json']
+	})
+};

packages/package/test/fixtures/tsconfig-specified/tsconfig.build.json

@@ -0,0 +1,6 @@
+{
+	"extends": "./tsconfig.json",
+	"compilerOptions": {
+		"removeComments": true
+	}
+}

packages/package/test/fixtures/tsconfig-specified/tsconfig.json

@@ -0,0 +1,6 @@
+{
+	"compilerOptions": {
+		"target": "ESNext",
+		"module": "ESNext"
+	}
+}

packages/package/test/index.js

@@ -151,6 +151,10 @@ test('SvelteKit interop', async () => {
 	await test_make_package('svelte-kit');
 });
 
+test('create package with tsconfig specified', async () => {
+	await test_make_package('tsconfig-specified', { tsconfig: 'tsconfig.build.json' });
+});
+
 // chokidar doesn't fire events in github actions :shrug:
 if (!process.env.CI) {
 	test('watches for changes', async () => {