Fix missing type-attribute in xml-stylesheet with xslt extension (#13867)

Adriel-M · florian-lefebvre · web-flow · commit c947c28ae7c3 · 2025-06-03T11:28:53.000+02:00
Co-authored-by: Florian Lefebvre &lt;contact@florian-lefebvre.dev&gt;
diff --git a/.changeset/huge-islands-fold.md b/.changeset/huge-islands-fold.md
@@ -0,0 +1,5 @@
+---
+'@astrojs/rss': patch
+---
+
+Fixes a missing type attribute when providing a XSLT stylesheet
diff --git a/packages/astro-rss/src/index.ts b/packages/astro-rss/src/index.ts
@@ -173,7 +173,7 @@ async function generateRSS(rssOptions: ValidatedRSSOptions): Promise<string> {
 	const parser = new XMLParser(xmlOptions);
 	const root: any = { '?xml': { '@_version': '1.0', '@_encoding': 'UTF-8' } };
 	if (typeof rssOptions.stylesheet === 'string') {
-		const isXSL = /\.xsl$/i.test(rssOptions.stylesheet);
+		const isXSL = /\.xslt?$/i.test(rssOptions.stylesheet);
 		root['?xml-stylesheet'] = {
 			'@_href': rssOptions.stylesheet,
 			...(isXSL && { '@_type': 'text/xsl' }),
diff --git a/packages/astro-rss/test/rss.test.js b/packages/astro-rss/test/rss.test.js
@@ -35,6 +35,8 @@ const validXmlWithCustomDataResult = `<?xml version="1.0" encoding="UTF-8"?><rss
 const validXmlWithStylesheet = `<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet href="/feedstylesheet.css"?><rss version="2.0"><channel><title><![CDATA[${title}]]></title><description><![CDATA[${description}]]></description><link>${site}/</link></channel></rss>`;
 // biome-ignore format: keep in one line
 const validXmlWithXSLStylesheet = `<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet href="/feedstylesheet.xsl" type="text/xsl"?><rss version="2.0"><channel><title><![CDATA[${title}]]></title><description><![CDATA[${description}]]></description><link>${site}/</link></channel></rss>`;
+// biome-ignore format: keep in one line
+const validXmlWithXSLTStylesheet = `<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet href="/feedstylesheet.xslt" type="text/xsl"?><rss version="2.0"><channel><title><![CDATA[${title}]]></title><description><![CDATA[${description}]]></description><link>${site}/</link></channel></rss>`;
 
 function assertXmlDeepEqual(a, b) {
 	const parsedA = parseXmlString(a);
@@ -161,9 +163,25 @@ describe('getRssString', () => {
 			stylesheet: '/feedstylesheet.xsl',
 		});
 
+		// xml2js doesn't parse processing instructions. Assert the type is present.
+		assert.equal(str.includes('type="text/xsl"'), true);
 		assertXmlDeepEqual(str, validXmlWithXSLStylesheet);
 	});
 
+	it('should include xml-stylesheet instruction with xslt type when stylesheet is set to xslt file', async () => {
+		const str = await getRssString({
+			title,
+			description,
+			items: [],
+			site,
+			stylesheet: '/feedstylesheet.xslt',
+		});
+
+		// xml2js doesn't parse processing instructions. Assert the type is present.
+		assert.equal(str.includes('type="text/xsl"'), true);
+		assertXmlDeepEqual(str, validXmlWithXSLTStylesheet);
+	});
+
 	it('should preserve self-closing tags on `customData`', async () => {
 		const customData =
 			'<atom:link href="https://example.com/feed.xml" rel="self" type="application/rss+xml"/>';

-Original file line number
+Diff line change
@@ @@ -0,0 +1,5 @@ @@
 +---
 +'@astrojs/rss': patch
 +---
++
 +Fixes a missing type attribute when providing a XSLT stylesheet