From af83a32c9efe70593112e4dded0f9f61f08c6616 Mon Sep 17 00:00:00 2001
From: Alexander Davydov <nyddle@gmail.com>
Date: Wed, 18 Mar 2026 15:02:03 +0300
Subject: [PATCH] GigaChat: broaden leaked prelude stripping

---
 src/agents/gigachat-stream.leaked-prelude.test.ts | 8 ++++++--
 src/agents/gigachat-stream.ts                     | 2 +-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/agents/gigachat-stream.leaked-prelude.test.ts b/src/agents/gigachat-stream.leaked-prelude.test.ts
index 251516566c1..e41c852f4d2 100644
--- a/src/agents/gigachat-stream.leaked-prelude.test.ts
+++ b/src/agents/gigachat-stream.leaked-prelude.test.ts
@@ -22,11 +22,15 @@ function createSseStream(lines: string[]): Readable {
 }
 
 describe("GigaChat leaked function-call prelude cleanup", () => {
-  it("drops leaked assistant text preludes when a function call is present", async () => {
+  it.each([
+    "assistant function callrecipient{",
+    "assistant function callweather{",
+    "assistant function call recipient {",
+  ])("drops leaked assistant text prelude %p when a function call is present", async (prelude) => {
     request.mockResolvedValueOnce({
       status: 200,
       data: createSseStream([
-        'data: {"choices":[{"delta":{"content":"assistant function callrecipient{","role":"assistant"},"index":0}]}',
+        `data: {"choices":[{"delta":{"content":"${prelude}","role":"assistant"},"index":0}]}`,
         'data: {"choices":[{"delta":{"content":"","role":"assistant","function_call":{"name":"message","arguments":"{\\"action\\":\\"send\\",\\"message\\":\\"hello\\"}"}},"index":0}]}',
         "data: [DONE]",
       ]),
diff --git a/src/agents/gigachat-stream.ts b/src/agents/gigachat-stream.ts
index 27fb5339dd6..504fe61a0a0 100644
--- a/src/agents/gigachat-stream.ts
+++ b/src/agents/gigachat-stream.ts
@@ -40,7 +40,7 @@ export type GigachatStreamOptions = {
 };
 
 function stripLeakedFunctionCallPrelude(text: string): string {
-  return text.replace(/^\s*assistant\s+function\s+call(?:recipient)?\{\s*/i, "");
+  return text.replace(/^\s*assistant\s+function\s+call(?:\s*([A-Za-z0-9_.:/-]+))?\s*\{\s*/i, "");
 }
 
 // ── Function name sanitization ──────────────────────────────────────────────