serverless: Fix Connection.run() implementation

packages/turso-serverless/src/protocol.ts

@@ -192,52 +192,71 @@ export async function executeCursor(
 
   const decoder = new TextDecoder();
   let buffer = '';
-  let isFirstLine = true;
-  let cursorResponse: CursorResponse;
+  let cursorResponse: CursorResponse | undefined;
+
+  // First, read until we get the cursor response (first line)
+  while (!cursorResponse) {
+    const { done, value } = await reader.read();
+    if (done) break;
+
+    buffer += decoder.decode(value, { stream: true });
+    
+    const newlineIndex = buffer.indexOf('\n');
+    if (newlineIndex !== -1) {
+      const line = buffer.slice(0, newlineIndex).trim();
+      buffer = buffer.slice(newlineIndex + 1);
+      
+      if (line) {
+        cursorResponse = JSON.parse(line);
+        break;
+      }
+    }
+  }
+
+  if (!cursorResponse) {
+    throw new DatabaseError('No cursor response received');
+  }
 
   async function* parseEntries(): AsyncGenerator<CursorEntry> {
     try {
+      // Process any remaining data in the buffer
+      let newlineIndex;
+      while ((newlineIndex = buffer.indexOf('\n')) !== -1) {
+        const line = buffer.slice(0, newlineIndex).trim();
+        buffer = buffer.slice(newlineIndex + 1);
+        
+        if (line) {
+          yield JSON.parse(line) as CursorEntry;
+        }
+      }
+
+      // Continue reading from the stream
       while (true) {
         const { done, value } = await reader!.read();
         if (done) break;
 
         buffer += decoder.decode(value, { stream: true });
         
-        let newlineIndex;
         while ((newlineIndex = buffer.indexOf('\n')) !== -1) {
           const line = buffer.slice(0, newlineIndex).trim();
           buffer = buffer.slice(newlineIndex + 1);
           
           if (line) {
-            if (isFirstLine) {
-              cursorResponse = JSON.parse(line);
-              isFirstLine = false;
-            } else {
-              yield JSON.parse(line) as CursorEntry;
-            }
+            yield JSON.parse(line) as CursorEntry;
           }
         }
       }
+
+      // Process any remaining data in the buffer
+      if (buffer.trim()) {
+        yield JSON.parse(buffer.trim()) as CursorEntry;
+      }
     } finally {
       reader!.releaseLock();
     }
   }
 
-  const entries = parseEntries();
-  
-  // Get the first entry to parse the cursor response
-  const firstEntry = await entries.next();
-  if (!firstEntry.done) {
-    // Put the first entry back
-    const generator = (async function* () {
-      yield firstEntry.value;
-      yield* entries;
-    })();
-    
-    return { response: cursorResponse!, entries: generator };
-  }
-  
-  return { response: cursorResponse!, entries };
+  return { response: cursorResponse, entries: parseEntries() };
 }
 
 export async function executePipeline(