fix attribute parsing

src/index.ts

@@ -35,19 +35,17 @@ function defaultOnerror(error: Error) {
 	throw error;
 }
 
-function parseAttributeValue(value: string | boolean) {
-	const curated = (<string>value).replace(/"/ig, '');
-	if (curated === 'true' || curated === 'false') {
-		return curated === 'true';
-	}
-	return curated;
+function parseAttributeValue(value: string) {
+	return /^['"]/.test(value) ?
+		value.slice(1, -1) :
+		value;
 }
 
 function parseAttributes(str: string) {
 	const attrs = {};
 	str.split(/\s+/).filter(Boolean).forEach(attr => {
 		const [name, value] = attr.split('=');
-		attrs[name] = parseAttributeValue(value);
+		attrs[name] = value ? parseAttributeValue(value) : true;
 	});
 	return attrs;
 }

test/preprocess/index.js

@@ -112,13 +112,14 @@ describe.only('preprocess', () => {
 
 	it('parses attributes', () => {
 		const source = `
-			<style type='text/scss' bool></style>
+			<style type='text/scss' data-foo="bar" bool></style>
 		`;
 
 		return svelte.preprocess(source, {
 			style: ({ attributes }) => {
 				assert.deepEqual(attributes, {
 					type: 'text/scss',
+					'data-foo': 'bar',
 					bool: true
 				});
 			}