refac

src/lib/components/chat/Messages/ResponseMessage.svelte

@@ -121,13 +121,17 @@
 	export let messageId;
 	export let selectedModels = [];
 
-	let message: MessageType = structuredClone(history.messages[messageId]);
+	let messageSource = history.messages[messageId];
+	let message: MessageType = structuredClone(messageSource);
 	$: if (history.messages) {
 		const source = history.messages[messageId];
 		if (source) {
-			// Fast path: O(1) check on the fields that change most often (content during streaming, done at end)
-			// Avoids 2x O(n) JSON.stringify calls that are always true during streaming anyway
-			if (
+			// Fast path for the fields that change most often while streaming.
+			// Responses streams update output even when legacy content is unchanged.
+			if (source !== messageSource) {
+				messageSource = source;
+				message = structuredClone(source);
+			} else if (
 				message.content !== source.content ||
 				message.done !== source.done ||
 				message.output?.length !== source.output?.length