src/server/routes/health.test.ts

@@ -33,6 +33,10 @@ function createMockRes() {
   return res;
 }
 
+function createRequest() {
+  return {} as Parameters<ReturnType<typeof healthMiddleware>>[0];
+}
+
 describe("healthMiddleware", () => {
   beforeEach(() => {
     vi.useFakeTimers();
@@ -42,11 +46,11 @@ describe("healthMiddleware", () => {
     const apiClient = createMockApiClient("ok");
     const handler = healthMiddleware({ apiClient });
 
-    const req = {} as any;
+    const req = createRequest();
     const res = createMockRes();
     const next = vi.fn();
 
-    await handler(req, res as any, next);
+    await handler(req, res, next);
 
     expect(res.status).toHaveBeenCalledWith(200);
     expect(res.json).toHaveBeenCalledWith({ status: "ok" });
@@ -56,11 +60,11 @@ describe("healthMiddleware", () => {
     const apiClient = createMockApiClient("error");
     const handler = healthMiddleware({ apiClient });
 
-    const req = {} as any;
+    const req = createRequest();
     const res = createMockRes();
     const next = vi.fn();
 
-    await handler(req, res as any, next);
+    await handler(req, res, next);
 
     expect(res.status).toHaveBeenCalledWith(503);
     expect(res.json).toHaveBeenCalledWith({
@@ -73,9 +77,9 @@ describe("healthMiddleware", () => {
     const apiClient = createMockApiClient("ok");
     const handler = healthMiddleware({ apiClient });
 
-    const req = {} as any;
+    const req = createRequest();
     const res1 = createMockRes();
-    await handler(req, res1 as any, vi.fn());
+    await handler(req, res1, vi.fn());
     expect(res1.status).toHaveBeenCalledWith(200);
 
     // Now make it fail
@@ -85,7 +89,7 @@ describe("healthMiddleware", () => {
     vi.advanceTimersByTime(30_000);
 
     const res2 = createMockRes();
-    await handler(req, res2 as any, vi.fn());
+    await handler(req, res2, vi.fn());
     expect(res2.status).toHaveBeenCalledWith(200);
   });
 
@@ -93,9 +97,9 @@ describe("healthMiddleware", () => {
     const apiClient = createMockApiClient("ok");
     const handler = healthMiddleware({ apiClient });
 
-    const req = {} as any;
+    const req = createRequest();
     const res1 = createMockRes();
-    await handler(req, res1 as any, vi.fn());
+    await handler(req, res1, vi.fn());
     expect(res1.status).toHaveBeenCalledWith(200);
 
     // Now make it fail
@@ -105,7 +109,7 @@ describe("healthMiddleware", () => {
     vi.advanceTimersByTime(61_000);
 
     const res2 = createMockRes();
-    await handler(req, res2 as any, vi.fn());
+    await handler(req, res2, vi.fn());
     expect(res2.status).toHaveBeenCalledWith(503);
   });
 
@@ -116,12 +120,12 @@ describe("healthMiddleware", () => {
       upstreamTimeoutMs: 100,
     });
 
-    const req = {} as any;
+    const req = createRequest();
     const res = createMockRes();
     const next = vi.fn();
 
     // The handler should abort the ping after 100ms
-    const promise = handler(req, res as any, next);
+    const promise = handler(req, res, next);
     vi.advanceTimersByTime(200);
     await promise;
 
@@ -132,11 +136,11 @@ describe("healthMiddleware", () => {
     const apiClient = createMockApiClient("ok");
     const handler = healthMiddleware({ apiClient });
 
-    const req = {} as any;
+    const req = createRequest();
     const res = createMockRes();
     const next = vi.fn();
 
-    await handler(req, res as any, next);
+    await handler(req, res, next);
 
     expect(next).not.toHaveBeenCalled();
   });

src/server/routes/health.ts

@@ -1,11 +1,16 @@
 import type { ApiClient } from "@/shared/api/client.js";
-import type { IncomingMessage, ServerResponse } from "node:http";
 
 export interface HealthMiddlewareOptions {
   apiClient: ApiClient;
   upstreamTimeoutMs?: number;
 }
 
+/** Express-style response with status/json helpers. */
+interface HealthResponse {
+  status(code: number): HealthResponse;
+  json(body: unknown): void;
+}
+
 const STALE_THRESHOLD_MS = 60_000;
 const DEFAULT_UPSTREAM_TIMEOUT_MS = 5_000;
 
@@ -24,11 +29,8 @@ export function healthMiddleware(options: HealthMiddlewareOptions) {
   let lastSuccessTs = 0;
 
   return async (
-    _req: IncomingMessage,
-    res: ServerResponse & {
-      status: (code: number) => ServerResponse;
-      json: (body: unknown) => void;
-    },
+    _req: unknown,
+    res: HealthResponse,
     _next: () => void,
   ): Promise<void> => {
     // Attempt to ping the upstream API

src/server/shutdown.test.ts

@@ -22,30 +22,48 @@ function createMockServer() {
 }
 
 describe("registerGracefulShutdown", () => {
-  let processOnSpy: ReturnType<typeof vi.spyOn>;
-  let processExitSpy: ReturnType<typeof vi.spyOn>;
+  /** Captured SIGTERM handlers from process.on */
+  let capturedHandlers: Array<() => void>;
+  let exitCalls: number[];
 
   beforeEach(() => {
-    processOnSpy = vi.spyOn(process, "on");
-    processExitSpy = vi
-      .spyOn(process, "exit")
-      .mockImplementation(() => undefined as never);
+    capturedHandlers = [];
+    exitCalls = [];
+
+    // Intercept process.on("SIGTERM", handler) without fighting spy types
+    process.on = ((event: string, listener: () => void) => {
+      if (event === "SIGTERM") {
+        capturedHandlers.push(listener);
+      }
+      return process;
+    }) as typeof process.on;
+
+    // Intercept process.exit
+    process.exit = ((code?: number) => {
+      exitCalls.push(code ?? 0);
+    }) as typeof process.exit;
+
     vi.useFakeTimers();
   });
 
   afterEach(() => {
-    processOnSpy.mockRestore();
-    processExitSpy.mockRestore();
+    vi.restoreAllMocks();
     vi.useRealTimers();
   });
 
+  function triggerSigterm(): void {
+    expect(capturedHandlers.length).toBeGreaterThan(0);
+    const handler = capturedHandlers[0];
+    if (handler) handler();
+  }
+
   it("registers a SIGTERM handler", () => {
     const logger = createMockLogger();
     const server = createMockServer();
 
     registerGracefulShutdown({ logger, server });
 
-    expect(processOnSpy).toHaveBeenCalledWith("SIGTERM", expect.any(Function));
+    expect(capturedHandlers).toHaveLength(1);
   });
 
   it("calls server.close on SIGTERM", async () => {
@@ -53,16 +71,8 @@ describe("registerGracefulShutdown", () => {
     const server = createMockServer();
 
     registerGracefulShutdown({ logger, server });
+    triggerSigterm();
 
-    // Extract and call the SIGTERM handler
-    const sigtermCall = processOnSpy.mock.calls.find(
-      (call) => call[0] === "SIGTERM",
-    );
-    expect(sigtermCall).toBeDefined();
-    const handler = sigtermCall![1] as () => void;
-    handler();
-
-    // Let microtasks resolve
     await vi.advanceTimersByTimeAsync(0);
 
     expect(server.close).toHaveBeenCalled();
@@ -73,12 +83,7 @@ describe("registerGracefulShutdown", () => {
     const server = createMockServer();
 
     registerGracefulShutdown({ logger, server });
-
-    const sigtermCall = processOnSpy.mock.calls.find(
-      (call) => call[0] === "SIGTERM",
-    );
-    const handler = sigtermCall![1] as () => void;
-    handler();
+    triggerSigterm();
 
     await vi.advanceTimersByTimeAsync(0);
 
@@ -90,16 +95,11 @@ describe("registerGracefulShutdown", () => {
     const server = createMockServer();
 
     registerGracefulShutdown({ logger, server });
-
-    const sigtermCall = processOnSpy.mock.calls.find(
-      (call) => call[0] === "SIGTERM",
-    );
-    const handler = sigtermCall![1] as () => void;
-    handler();
+    triggerSigterm();
 
     await vi.advanceTimersByTimeAsync(0);
 
-    expect(processExitSpy).toHaveBeenCalledWith(0);
+    expect(exitCalls).toContain(0);
   });
 
   it("force-exits with code 1 if drain times out", async () => {
@@ -109,17 +109,12 @@ describe("registerGracefulShutdown", () => {
     };
 
     registerGracefulShutdown({ logger, server, drainTimeoutMs: 1000 });
-
-    const sigtermCall = processOnSpy.mock.calls.find(
-      (call) => call[0] === "SIGTERM",
-    );
-    const handler = sigtermCall![1] as () => void;
-    handler();
+    triggerSigterm();
 
     // Advance past the drain timeout
     await vi.advanceTimersByTimeAsync(1100);
 
-    expect(processExitSpy).toHaveBeenCalledWith(1);
+    expect(exitCalls).toContain(1);
   });
 
   it("logs shutdown lifecycle events", async () => {
@@ -127,12 +122,7 @@ describe("registerGracefulShutdown", () => {
     const server = createMockServer();
 
     registerGracefulShutdown({ logger, server });
-
-    const sigtermCall = processOnSpy.mock.calls.find(
-      (call) => call[0] === "SIGTERM",
-    );
-    const handler = sigtermCall![1] as () => void;
-    handler();
+    triggerSigterm();
 
     await vi.advanceTimersByTimeAsync(0);
 
@@ -153,19 +143,14 @@ describe("registerGracefulShutdown", () => {
     };
 
     registerGracefulShutdown({ logger, server });
-
-    const sigtermCall = processOnSpy.mock.calls.find(
-      (call) => call[0] === "SIGTERM",
-    );
-    const handler = sigtermCall![1] as () => void;
-    handler();
+    triggerSigterm();
 
     // Shouldn't have exited yet at 29s
     vi.advanceTimersByTime(29_000);
-    expect(processExitSpy).not.toHaveBeenCalled();
+    expect(exitCalls).toHaveLength(0);
 
     // Should force-exit at 30s
     vi.advanceTimersByTime(2_000);
-    expect(processExitSpy).toHaveBeenCalledWith(1);
+    expect(exitCalls).toContain(1);
   });
 });