Fix status checks through jump hosts (#1045)

src/backend/ssh/host-metrics-helpers.test.ts

@@ -1,8 +1,10 @@
-import { describe, it, expect } from "vitest";
+import type { Client } from "ssh2";
+import { describe, it, expect, vi } from "vitest";
 import {
   supportsMetrics,
   isTcpPingEnabled,
   createConnectionLog,
+  tcpPingThroughJumpHost,
 } from "./host-metrics-helpers.js";
 
 describe("supportsMetrics", () => {
@@ -66,3 +68,57 @@ describe("createConnectionLog", () => {
     expect("timestamp" in entry).toBe(false);
   });
 });
+
+describe("tcpPingThroughJumpHost", () => {
+  it("reports the final destination online when forwarding succeeds", async () => {
+    const stream = { destroy: vi.fn() };
+    const jumpClient = {
+      end: vi.fn(),
+      forwardOut: vi.fn((_src, _srcPort, host, port, callback) => {
+        expect(host).toBe("private.example");
+        expect(port).toBe(22);
+        callback(undefined, stream);
+      }),
+    } as unknown as Pick<Client, "forwardOut" | "end">;
+
+    await expect(
+      tcpPingThroughJumpHost(jumpClient, "private.example", 22),
+    ).resolves.toBe(true);
+    expect(stream.destroy).toHaveBeenCalledOnce();
+    expect(jumpClient.end).toHaveBeenCalledOnce();
+  });
+
+  it("reports the final destination offline when forwarding fails", async () => {
+    const jumpClient = {
+      end: vi.fn(),
+      forwardOut: vi.fn((_src, _srcPort, _host, _port, callback) => {
+        callback(new Error("Connection refused"));
+      }),
+    } as unknown as Pick<Client, "forwardOut" | "end">;
+
+    await expect(
+      tcpPingThroughJumpHost(jumpClient, "private.example", 22),
+    ).resolves.toBe(false);
+    expect(jumpClient.end).toHaveBeenCalledOnce();
+  });
+
+  it("reports the final destination offline when forwarding times out", async () => {
+    vi.useFakeTimers();
+    const jumpClient = {
+      end: vi.fn(),
+      forwardOut: vi.fn(),
+    } as unknown as Pick<Client, "forwardOut" | "end">;
+
+    const result = tcpPingThroughJumpHost(
+      jumpClient,
+      "private.example",
+      22,
+      5000,
+    );
+    await vi.advanceTimersByTimeAsync(5000);
+
+    await expect(result).resolves.toBe(false);
+    expect(jumpClient.end).toHaveBeenCalledOnce();
+    vi.useRealTimers();
+  });
+});