From 062555ce9874a44eb50a74f79ee32ff62fb50fff Mon Sep 17 00:00:00 2001
From: Xiangzhe <32761048+xz-dev@users.noreply.github.com>
Date: Thu, 6 Aug 2026 09:41:43 +0800
Subject: [PATCH] feat(admission): add adaptive overload protection for LLM
 routes (#9262)
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Validated in local merge-train (devbox-vm-06-dev002) @ combined-tip (FAST gates — only pre-existing audit.test.ts flake).
---
 tests/unit/ollama-transform.test.ts | 44 +++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/tests/unit/ollama-transform.test.ts b/tests/unit/ollama-transform.test.ts
index 22cab56898..79e901eb37 100644
--- a/tests/unit/ollama-transform.test.ts
+++ b/tests/unit/ollama-transform.test.ts
@@ -100,6 +100,50 @@ test("transformToOllama handles string tool_call id normally", async () => {
   assert.ok(toolCallLine, "Should produce a tool call line");
 });
 
+test("transformToOllama passes through non-ok shared responses without rewriting status or body", async () => {
+  const errorBody = {
+    error: {
+      message: "Request too large for current capacity",
+      type: "server_error",
+      code: "admission_oversized",
+    },
+  };
+  const upstream = new Response(JSON.stringify(errorBody), {
+    status: 503,
+    headers: {
+      "Content-Type": "application/json",
+      "Retry-After": "1",
+    },
+  });
+
+  const result = transformToOllama(upstream, "llama3.2");
+  assert.equal(result.status, 503);
+  assert.equal(result.headers.get("Retry-After"), "1");
+  assert.match(String(result.headers.get("Content-Type") || ""), /application\/json/i);
+
+  const payload = await result.json();
+  assert.equal(payload.error?.code, "admission_oversized");
+  assert.equal(payload.error?.type, "server_error");
+  assert.equal(payload.error?.message, "Request too large for current capacity");
+});
+
+test("transformToOllama leaves successful non-SSE responses untouched", async () => {
+  const body = { choices: [{ message: { role: "assistant", content: "hello" } }] };
+  const upstream = new Response(JSON.stringify(body), {
+    status: 200,
+    headers: {
+      "Content-Type": "application/json",
+      "X-Sentinel": "preserved",
+    },
+  });
+
+  const result = transformToOllama(upstream, "llama3.2");
+  assert.equal(result, upstream);
+  assert.equal(result.status, 200);
+  assert.equal(result.headers.get("X-Sentinel"), "preserved");
+  assert.deepEqual(await result.json(), body);
+});
+
 test("transformToOllama emits reasoning aliases as native thinking", async () => {
   const inputSSE = [
     `data: ${JSON.stringify({