pages/blog/[...slug].js

@@ -32,8 +32,10 @@ export async function getStaticProps({ params }) {
   const authorDetails = await Promise.all(authorPromise)
 
   // rss
+  if (allPosts.length > 0) {
     const rss = generateRss(allPosts)
     fs.writeFileSync('./public/feed.xml', rss)
+  }
 
   return { props: { post, authorDetails, prev, next } }
 }

pages/tags/[tag].js

@@ -30,10 +30,12 @@ export async function getStaticProps({ params }) {
   )
 
   // rss
+  if (filteredPosts.length > 0) {
     const rss = generateRss(filteredPosts, `tags/${params.tag}/feed.xml`)
     const rssPath = path.join(root, 'public', 'tags', params.tag)
     fs.mkdirSync(rssPath, { recursive: true })
     fs.writeFileSync(path.join(rssPath, 'feed.xml'), rss)
+  }
 
   return { props: { posts: filteredPosts, tag: params.tag } }
 }