Throw the error when site option is missing (#3956)

* Throw the error when site option is missing

* Update index.ts

* Update index.ts

* Update rss.test.js

* Update index.ts

Co-authored-by: Fred K. Schott <fkschott@gmail.com>

.changeset/many-glasses-roll.md

@@ -0,0 +1,5 @@
+---
+'@astrojs/rss': patch
+---
+
+Throw the error when 'site' option is missing

packages/astro-rss/src/index.ts

@@ -76,10 +76,17 @@ function mapGlobResult(items: GlobResult): Promise<RSSFeedItem[]> {
 }
 
 export default async function getRSS(rssOptions: RSSOptions) {
+	const { site } = rssOptions;
 	let { items } = rssOptions;
+
+	if (!site) {
+		throw new Error('[RSS] the "site" option is required, but no value was given.');
+	}
+
 	if (isGlobResult(items)) {
 		items = await mapGlobResult(items);
 	}
+	
 	return {
 		body: await generateRSS({
 			rssOptions,

packages/astro-rss/test/rss.test.js

@@ -125,6 +125,20 @@ describe('rss', () => {
 	});
 
 	describe('errors', () => {
+		it('should provide a error message when a "site" option is missing', async () => {
+			try {
+				await rss({
+					title,
+					description,
+					items: [phpFeedItem, web1FeedItem]
+				});
+		
+				chai.expect(false).to.equal(true, 'Should have errored');
+			} catch (err) {
+        chai.expect(err.message).to.contain('[RSS] the "site" option is required, but no value was given.');
+			}
+		});
+		
 		it('should provide a good error message when a link is not provided', async () => {
 			try {
 				await rss({