chore: remove dependency on chokidar

.changeset/quiet-owls-watch.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/package': patch
+---
+
+chore: remove dependency on chokidar

packages/package/package.json

@@ -20,7 +20,6 @@
 	"homepage": "https://svelte.dev",
 	"type": "module",
 	"dependencies": {
-		"chokidar": "^5.0.0",
 		"sade": "^1.8.1",
 		"semver": "^7.8.5",
 		"svelte2tsx": "~0.7.56"

packages/package/src/index.js

@@ -1,7 +1,6 @@
 import * as fs from 'node:fs';
 import * as path from 'node:path';
 import { styleText } from 'node:util';
-import chokidar from 'chokidar';
 import { preprocess } from 'svelte/compiler';
 import { copy, mkdirp, posixify, rimraf } from './filesystem.js';
 import {
@@ -94,6 +93,9 @@ export async function watch(options) {
 	/** @type {Array<{ file: import('./types.js').File, type: string }>} */
 	const pending = [];
 
+	// Remember files because deleted paths cannot be stat-ed to distinguish them from directories.
+	const known_files = new Set(scan(input, extensions).map((file) => file.name));
+
 	/** @type {Array<(value?: any) => void>} */
 	const fulfillers = [];
 
@@ -103,22 +105,48 @@ export async function watch(options) {
 	/** @type {Map<string, import('typescript').CompilerOptions>} */
 	const tsconfig_cache = new Map();
 
-	const watcher = chokidar.watch(input, { ignoreInitial: true });
-	/** @type {Promise<void>} */
-	const ready = new Promise((resolve) => watcher.on('ready', resolve));
-
-	watcher.on('all', (type, filepath) => {
-		const file = analyze(path.relative(input, filepath), extensions);
+	/**
+	 * @param {string} name
+	 * @param {string} type
+	 */
+	function enqueue(name, type) {
+		const file = analyze(name, extensions);
 
-		pending.push({ file, type });
+		if (!pending.some((event) => event.type === type && event.file.name === file.name)) {
+			pending.push({ file, type });
+		}
 
 		if (
 			file.name.endsWith('tsconfig.json') ||
 			file.name.endsWith('jsconfig.json') ||
-			(options.tsconfig && posixify(filepath) === posixify(options.tsconfig))
+			(options.tsconfig && posixify(path.join(input, name)) === posixify(options.tsconfig))
 		) {
 			tsconfig_cache.clear();
 		}
+	}
+
+	const watcher = fs.watch(input, { recursive: true }, (_, filename) => {
+		if (filename !== null) {
+			const name = posixify(filename);
+			const stats = fs.statSync(path.join(input, filename), { throwIfNoEntry: false });
+
+			if (stats) {
+				if (!stats.isFile()) return;
+				known_files.add(name);
+				enqueue(name, 'change');
+			} else if (known_files.delete(name)) {
+				enqueue(name, 'unlink');
+			} else {
+				// a removed directory only fires an event for itself, not for the files inside it
+				const children = [...known_files].filter((child) => child.startsWith(name + '/'));
+				if (children.length === 0) return;
+
+				for (const child of children) {
+					known_files.delete(child);
+					enqueue(child, 'unlink');
+				}
+			}
+		}
 
 		clearTimeout(timeout);
 		timeout = setTimeout(async () => {
@@ -151,7 +179,7 @@ export async function watch(options) {
 					console.log(`Removed ${file.dest}`);
 				}
 
-				if (type === 'add' || type === 'change') {
+				if (type === 'change') {
 					console.log(`Processing ${file.name}`);
 					try {
 						await process_file(
@@ -193,7 +221,6 @@ export async function watch(options) {
 
 	return {
 		watcher,
-		ready,
 		settled: () =>
 			new Promise((fulfil, reject) => {
 				fulfillers.push(fulfil);

packages/package/test/index.spec.js

@@ -181,7 +181,7 @@ 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:
+// File watching is unreliable in GitHub Actions
 if (!process.env.CI) {
 	test('watches for changes', async () => {
 		const cwd = join(import.meta.dirname, 'watch');
@@ -190,7 +190,7 @@ if (!process.env.CI) {
 		const config = await load_config();
 		process.chdir(original_cwd);
 
-		const { watcher, ready, settled } = await watch({
+		const { watcher, settled } = await watch({
 			cwd,
 			input: 'src/lib',
 			output: 'package',
@@ -224,8 +224,6 @@ if (!process.env.CI) {
 		}
 
 		try {
-			await ready;
-
 			// completes initial build
 			compare('index.js');
 
@@ -255,13 +253,32 @@ if (!process.env.CI) {
 			write('src/lib/post-error.svelte', '<button on:click={foo}>click me</button>');
 			await settled();
 			compare('post-error.svelte');
+
+			// removes outputs when a source file is deleted
+			remove('src/lib/a.js');
+			await settled();
+			expect(fs.existsSync(join(cwd, 'package/a.js'))).toBe(false);
+			expect(fs.existsSync(join(cwd, 'package/a.d.ts'))).toBe(false);
+
+			// removes outputs when a directory is renamed
+			fs.mkdirSync(join(cwd, 'src/lib/sub'));
+			write('src/lib/sub/c.js', "export const c = 'c';");
+			await settled();
+			expect(fs.existsSync(join(cwd, 'package/sub/c.js'))).toBe(true);
+
+			fs.renameSync(join(cwd, 'src/lib/sub'), join(cwd, 'src/lib/sub2'));
+			await settled();
+			expect(fs.existsSync(join(cwd, 'package/sub/c.js'))).toBe(false);
+			expect(fs.existsSync(join(cwd, 'package/sub2/c.js'))).toBe(true);
 		} finally {
-			await watcher.close();
+			watcher.close();
 
 			remove('src/lib/Test.svelte');
 			remove('src/lib/a.js');
 			remove('src/lib/b.ts');
 			remove('src/lib/post-error.svelte');
+			fs.rmSync(join(cwd, 'src/lib/sub'), { recursive: true, force: true });
+			fs.rmSync(join(cwd, 'src/lib/sub2'), { recursive: true, force: true });
 		}
 	}, 30_000);
 }