fix: Failed to execute 'encode' on 'TextEncoder': parameter 1 is not of type 'String' in Edge Runtime SSR (#6070)

* minor fixes for errors related to vercel SSR in core

* yielding empty string instead of nothing, to not exit the iterator

---------

Co-authored-by: AirBorne04 <>

.changeset/curvy-owls-grow.md

@@ -0,0 +1,6 @@
+---
+'astro': patch
+---
+
+* safe guard against TextEncode.encode(HTMLString) [errors on vercel edge]
+* safe guard against html.replace when html is undefined

packages/astro/src/runtime/server/render/common.ts

@@ -93,5 +93,7 @@ export function chunkToByteArray(
 	if (chunk instanceof Uint8Array) {
 		return chunk as Uint8Array;
 	}
-	return encoder.encode(stringifyChunk(result, chunk));
+  // stringify chunk might return a HTMLString
+  let stringified = stringifyChunk(result, chunk);
+	return encoder.encode(stringified.toString());
 }

packages/astro/src/runtime/server/render/component.ts

@@ -261,9 +261,11 @@ If you're still stuck, please open an issue on GitHub or join us at https://astr
 
 			if (isPage || renderer?.name === 'astro:jsx') {
 				yield html;
-			} else {
+			} else if(html && html.length > 0) {
 				yield markHTMLString(html.replace(/\<\/?astro-slot\>/g, ''));
-			}
+			} else {
+        yield '';
+       }
 		})();
 	}