From 30cf91e27258a46d405de0084305d9d9adc516c0 Mon Sep 17 00:00:00 2001
From: csoftware-arigpt <ksoarigpt@gmail.com>
Date: Mon, 27 Jul 2026 20:18:20 +0300
Subject: [PATCH] Preserve #3440 coverage under signature replay

Seed a connection-scoped Gemini thought signature before exercising the Claude-to-Gemini id assertions. This keeps the regression focused on the public-Gemini versus Vertex id contract while honoring the new signature replay behavior.

Constraint: Signature-less historical Claude tool calls are intentionally converted to context text.

Rejected: Emit unsigned functionCall parts in the fixture | Gemini 3+ rejects that production behavior.

Confidence: high

Scope-risk: narrow

Tested: Prettier, repository ESLint hook, vertex-functioncall-id-3440 Node test, git diff --check

Not-tested: Full repository test suite
---
 .../unit/vertex-functioncall-id-3440.test.ts  | 34 ++++++++++++++-----
 1 file changed, 26 insertions(+), 8 deletions(-)

diff --git a/tests/unit/vertex-functioncall-id-3440.test.ts b/tests/unit/vertex-functioncall-id-3440.test.ts
index 8609755c36..758557e374 100644
--- a/tests/unit/vertex-functioncall-id-3440.test.ts
+++ b/tests/unit/vertex-functioncall-id-3440.test.ts
@@ -11,15 +11,24 @@
 import test from "node:test";
 import assert from "node:assert/strict";
 
-const { openaiToGeminiRequest } = await import(
-  "../../open-sse/translator/request/openai-to-gemini.ts"
-);
-const { claudeToGeminiRequest } = await import(
-  "../../open-sse/translator/request/claude-to-gemini.ts"
-);
+const { openaiToGeminiRequest } =
+  await import("../../open-sse/translator/request/openai-to-gemini.ts");
+const { claudeToGeminiRequest } =
+  await import("../../open-sse/translator/request/claude-to-gemini.ts");
+const { buildGeminiThoughtSignatureKey, storeGeminiThoughtSignature } =
+  await import("../../open-sse/services/geminiThoughtSignatureStore.ts");
 
 type UnknownRecord = Record<string, unknown>;
 
+const CLAUDE_SIGNATURE_NAMESPACE = "regression-3440";
+
+function seedClaudeThoughtSignature() {
+  storeGeminiThoughtSignature(
+    buildGeminiThoughtSignatureKey(CLAUDE_SIGNATURE_NAMESPACE, "tu_weather_1"),
+    "SIG_3440"
+  );
+}
+
 function findFunctionCall(result: any): UnknownRecord | undefined {
   for (const content of result.contents ?? []) {
     for (const part of content.parts ?? []) {
@@ -126,10 +135,16 @@ test("#3440 OpenAI->Gemini: no provider hint PRESERVES id (default, non-vertex)"
 });
 
 test("#3440 Claude->Gemini: vertex provider omits id from functionCall and functionResponse", () => {
+  seedClaudeThoughtSignature();
   const result = claudeToGeminiRequest("gemini-2.5-pro", CLAUDE_TOOL_BODY, false, {
     _provider: "vertex",
+    _signatureNamespace: CLAUDE_SIGNATURE_NAMESPACE,
   });
-  assert.equal(findFunctionCall(result)?.id, undefined, "functionCall.id must be omitted for Vertex");
+  assert.equal(
+    findFunctionCall(result)?.id,
+    undefined,
+    "functionCall.id must be omitted for Vertex"
+  );
   assert.equal(
     findFunctionResponse(result)?.id,
     undefined,
@@ -138,6 +153,9 @@ test("#3440 Claude->Gemini: vertex provider omits id from functionCall and funct
 });
 
 test("#3440 Claude->Gemini: no provider hint PRESERVES id (default, non-vertex)", () => {
-  const result = claudeToGeminiRequest("gemini-2.5-pro", CLAUDE_TOOL_BODY, false);
+  seedClaudeThoughtSignature();
+  const result = claudeToGeminiRequest("gemini-2.5-pro", CLAUDE_TOOL_BODY, false, {
+    _signatureNamespace: CLAUDE_SIGNATURE_NAMESPACE,
+  });
   assert.equal(findFunctionCall(result)?.id, "tu_weather_1");
 });