From 25f5d31fab005d6d542d20f33a725020ff6cea5d Mon Sep 17 00:00:00 2001
From: Neko Ayaka <neko@ayaka.moe>
Date: Tue, 3 Dec 2024 23:49:24 +0800
Subject: [PATCH] fix: unable to parse the result due to not check data: frame
 for sse

---
 packages/stream-text/src/index.ts | 36 ++++++++++++++++++++++---------
 1 file changed, 26 insertions(+), 10 deletions(-)

diff --git a/packages/stream-text/src/index.ts b/packages/stream-text/src/index.ts
index 4d2c815..629cfc1 100644
--- a/packages/stream-text/src/index.ts
+++ b/packages/stream-text/src/index.ts
@@ -42,6 +42,9 @@ export interface StreamTextResponse {
   usage?: StreamTextResponseUsage
 }
 
+const dataHeaderPrefix = 'data: '
+const dataErrorPrefix = `{"error":`
+
 /**
  * @experimental
  * WIP, currently only returns `textStream`, does not support function calling (tools).
@@ -64,20 +67,33 @@ export const streamText = async (options: StreamTextOptions): Promise<StreamText
       const rawChunkStream = res.body.pipeThrough(new TransformStream({
         transform: (chunk, controller) => {
           for (const line of decoder.decode(chunk).split('\n').filter(line => line)) {
-            if (line !== 'data: [DONE]') {
-              const data: StreamTextResponse = JSON.parse(line.slice(6))
+            // Some cases:
+            // - Empty chunk
+            // - :ROUTER PROCESSING from OpenRouter
+            if (!line || !line.startsWith(dataHeaderPrefix)) {
+              continue
+            }
 
-              controller.enqueue(data)
+            if (line.startsWith(dataErrorPrefix)) {
+              // About controller error: https://developer.mozilla.org/en-US/docs/Web/API/TransformStreamDefaultController/error
+              controller.error(new Error(`Error from server: ${line}`))
+              continue
+            }
 
-              if (data.choices[0].finish_reason) {
-                finishReason = data.choices[0].finish_reason
-              }
+            const lineWithoutPrefix = line.slice(dataHeaderPrefix.length)
+            if (lineWithoutPrefix === '[DONE]') {
+              controller.terminate()
+              continue
+            }
+
+            const data: StreamTextResponse = JSON.parse(line.slice(6))
+            controller.enqueue(data)
 
-              if (data.usage)
-                usage = data.usage
+            if (data.choices[0].finish_reason) {
+              finishReason = data.choices[0].finish_reason
             }
-            else {
-              controller.terminate()
+            if (data.usage) {
+              usage = data.usage
             }
           }
         },