fix

Author: Rich-Harris

packages/svelte/scripts/check-treeshakeability.js

@@ -5,10 +5,20 @@ import virtual from '@rollup/plugin-virtual';
 
 const pkg = JSON.parse(fs.readFileSync('package.json', 'utf8'));
 
+let failed = false;
+
+console.group('checking treeshakeability');
+
 for (const key in pkg.exports) {
+	// special cases
+	if (key === './compiler') continue;
+	if (key === './internal/disclose-version') continue;
+
 	for (const type of ['browser', 'default']) {
 		if (!pkg.exports[key][type]) continue;
 
+		const subpackage = path.join(pkg.name, key);
+
 		const resolved = path.resolve(pkg.exports[key][type]);
 
 		const bundle = await rollup({
@@ -29,10 +39,19 @@ for (const key in pkg.exports) {
 			throw new Error('errr what');
 		}
 
-		const { code } = output[0];
+		const code = output[0].code.replace(/import\s+([^'"]+from\s+)?(['"])[^'"]+\2\s*;?/, '');
 		if (code.trim()) {
 			console.error(code);
-			throw new Error(`${path.join(pkg.name, key)} ${type} export is not tree-shakeable`);
+			console.error(`❌ ${subpackage} (${type})`);
+			failed = true;
+		} else {
+			console.error(`✅ ${subpackage} (${type})`);
 		}
 	}
 }
+
+console.groupEnd();
+
+if (failed) {
+	process.exit(1);
+}

packages/svelte/src/internal/server/index.js

@@ -32,7 +32,7 @@ const INVALID_ATTR_NAME_CHAR_REGEX =
 	/[\s'">/=\u{FDD0}-\u{FDEF}\u{FFFE}\u{FFFF}\u{1FFFE}\u{1FFFF}\u{2FFFE}\u{2FFFF}\u{3FFFE}\u{3FFFF}\u{4FFFE}\u{4FFFF}\u{5FFFE}\u{5FFFF}\u{6FFFE}\u{6FFFF}\u{7FFFE}\u{7FFFF}\u{8FFFE}\u{8FFFF}\u{9FFFE}\u{9FFFF}\u{AFFFE}\u{AFFFF}\u{BFFFE}\u{BFFFF}\u{CFFFE}\u{CFFFF}\u{DFFFE}\u{DFFFF}\u{EFFFE}\u{EFFFF}\u{FFFFE}\u{FFFFF}\u{10FFFE}\u{10FFFF}]/u;
 
 // This is duplicated from the compiler, but we need it at runtime too.
-const DOMBooleans = [
+export const DOMBooleanAttributes = [
 	'allowfullscreen',
 	'async',
 	'autofocus',
@@ -59,9 +59,6 @@ const DOMBooleans = [
 	'selected'
 ];
 
-/** @type {Set<string>} */
-export const DOMBooleanAttributes = new Set(DOMBooleans);
-
 export const VoidElements = new Set([
 	'area',
 	'base',
@@ -280,7 +277,7 @@ export function spread_attributes(attrs, class_hash, additional) {
 
 	for (name in merged_attrs) {
 		if (INVALID_ATTR_NAME_CHAR_REGEX.test(name)) continue;
-		const is_boolean = DOMBooleanAttributes.has(name);
+		const is_boolean = DOMBooleanAttributes.includes(name);
 		attr_str += attr(name, merged_attrs[name], is_boolean);
 	}