chore(`@astrojs/rss`): Migrate tests to `node:test` (#9939)

* Progressively add new tests (remove old later)

* Finalize tests

* Remove unused comments

* Assert that errors are not present and add jsdocs to util function

* Fix

* Remove mocha deps

1 files changed, 19 insertions, 0 deletions

diff --git a/packages/astro-rss/test/test-utils.js b/packages/astro-rss/test/test-utils.js
index 4f0340333..dcc57df21 100644
--- a/packages/astro-rss/test/test-utils.js
+++ b/packages/astro-rss/test/test-utils.js
@@ -1,3 +1,5 @@
+import xml2js from 'xml2js';
+
 export const title = 'My RSS feed';
 export const description = 'This sure is a nice RSS feed';
 export const site = 'https://example.com';
@@ -45,3 +47,20 @@ export const web1FeedItemWithAllData = {
 		type: 'audio/mpeg',
 	},
 };
+
+const parser = new xml2js.Parser({ trim: true });
+
+/**
+ *
+ * Utility function to parse an XML string into an object using `xml2js`.
+ *
+ * @param {string} xmlString - Stringified XML to parse.
+ * @return {{ err: Error, result: any }} Represents an option containing the parsed XML string or an Error.
+ */
+export function parseXmlString(xmlString) {
+	let res;
+	parser.parseString(xmlString, (err, result) => {
+		res = { err, result };
+	});
+	return res;
+}