fix: prefer tailnet IP for local gateway calls

src/gateway/call.test.ts

@@ -0,0 +1,78 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+const loadConfig = vi.fn();
+const resolveGatewayPort = vi.fn();
+const pickPrimaryTailnetIPv4 = vi.fn();
+
+let lastClientOptions: {
+  url?: string;
+  onHelloOk?: () => void | Promise<void>;
+} | null = null;
+
+vi.mock("../config/config.js", () => ({
+  loadConfig,
+  resolveGatewayPort,
+}));
+
+vi.mock("../infra/tailnet.js", () => ({
+  pickPrimaryTailnetIPv4,
+}));
+
+vi.mock("./client.js", () => ({
+  GatewayClient: class {
+    constructor(opts: {
+      url?: string;
+      onHelloOk?: () => void | Promise<void>;
+    }) {
+      lastClientOptions = opts;
+    }
+    async request() {
+      return { ok: true };
+    }
+    start() {
+      void lastClientOptions?.onHelloOk?.();
+    }
+    stop() {}
+  },
+}));
+
+const { callGateway } = await import("./call.js");
+
+describe("callGateway url resolution", () => {
+  beforeEach(() => {
+    loadConfig.mockReset();
+    resolveGatewayPort.mockReset();
+    pickPrimaryTailnetIPv4.mockReset();
+    lastClientOptions = null;
+  });
+
+  it("uses tailnet IP when local bind is tailnet", async () => {
+    loadConfig.mockReturnValue({ gateway: { mode: "local", bind: "tailnet" } });
+    resolveGatewayPort.mockReturnValue(18800);
+    pickPrimaryTailnetIPv4.mockReturnValue("100.64.0.1");
+
+    await callGateway({ method: "health" });
+
+    expect(lastClientOptions?.url).toBe("ws://100.64.0.1:18800");
+  });
+
+  it("uses tailnet IP when local bind is auto and tailnet is present", async () => {
+    loadConfig.mockReturnValue({ gateway: { mode: "local", bind: "auto" } });
+    resolveGatewayPort.mockReturnValue(18800);
+    pickPrimaryTailnetIPv4.mockReturnValue("100.64.0.2");
+
+    await callGateway({ method: "health" });
+
+    expect(lastClientOptions?.url).toBe("ws://100.64.0.2:18800");
+  });
+
+  it("falls back to loopback when local bind is auto without tailnet IP", async () => {
+    loadConfig.mockReturnValue({ gateway: { mode: "local", bind: "auto" } });
+    resolveGatewayPort.mockReturnValue(18800);
+    pickPrimaryTailnetIPv4.mockReturnValue(undefined);
+
+    await callGateway({ method: "health" });
+
+    expect(lastClientOptions?.url).toBe("ws://127.0.0.1:18800");
+  });
+});