From b06ab4f27f05b873cf29f91d9b45ffd6fd2a988c Mon Sep 17 00:00:00 2001
From: t8y2 <1156263951@qq.com>
Date: Fri, 15 May 2026 14:38:15 +0800
Subject: [PATCH] fix(connection): handle stale connection state

---
 src/lib/connectionHealth.ts    | 25 +++++++++++++++++++++++++
 tests/connectionHealth.test.ts | 19 +++++++++++++++++++
 2 files changed, 44 insertions(+)
 create mode 100644 src/lib/connectionHealth.ts
 create mode 100644 tests/connectionHealth.test.ts

diff --git a/src/lib/connectionHealth.ts b/src/lib/connectionHealth.ts
new file mode 100644
index 0000000000..51b75f1492
--- /dev/null
+++ b/src/lib/connectionHealth.ts
@@ -0,0 +1,25 @@
+const CONNECTION_ERROR_PATTERNS = [
+  "connection",
+  "broken pipe",
+  "reset by peer",
+  "timed out",
+  "closed",
+  "eof",
+  "i/o error",
+];
+
+export function staleConnectionMessage(error: unknown): string {
+  if (error instanceof Error) return error.message;
+  return String(error);
+}
+
+export function shouldMarkDisconnected(error: unknown): boolean {
+  const message = staleConnectionMessage(error).toLowerCase();
+  return CONNECTION_ERROR_PATTERNS.some((pattern) => message.includes(pattern)) || hasConnectionOsError(message);
+}
+
+function hasConnectionOsError(message: string): boolean {
+  const osErrorCodes = new Set(["10053", "10054", "10057", "10058", "10060", "10061"]);
+  const match = message.match(/os error\s+(\d+)/);
+  return !!match && osErrorCodes.has(match[1]);
+}
diff --git a/tests/connectionHealth.test.ts b/tests/connectionHealth.test.ts
new file mode 100644
index 0000000000..46948f4e96
--- /dev/null
+++ b/tests/connectionHealth.test.ts
@@ -0,0 +1,19 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import { staleConnectionMessage, shouldMarkDisconnected } from "../src/lib/connectionHealth.ts";
+
+test("metadata connection errors should turn off connected state", () => {
+  assert.equal(shouldMarkDisconnected(new Error("connection closed by server")), true);
+  assert.equal(shouldMarkDisconnected("broken pipe"), true);
+  assert.equal(shouldMarkDisconnected("operation timed out"), true);
+});
+
+test("non-connection metadata errors should not turn off connected state", () => {
+  assert.equal(shouldMarkDisconnected(new Error("permission denied for table users")), false);
+  assert.equal(shouldMarkDisconnected("syntax error near SELECT"), false);
+});
+
+test("stale connection errors keep the original backend message", () => {
+  assert.equal(staleConnectionMessage(new Error("connection reset by peer")), "connection reset by peer");
+  assert.equal(staleConnectionMessage("closed"), "closed");
+});