test(telegram): scope fake timers in probe retry tests

src/telegram/probe.test.ts

@@ -1,13 +1,18 @@
-import { type Mock, describe, expect, it, vi, beforeEach, afterEach } from "vitest";
+import { type Mock, describe, expect, it, vi } from "vitest";
 import { withFetchPreconnect } from "../test-utils/fetch-mock.js";
 import { probeTelegram } from "./probe.js";
 
 describe("probeTelegram retry logic", () => {
   const token = "test-token";
   const timeoutMs = 5000;
-  let fetchMock: Mock;
 
-  function mockGetMeSuccess() {
+  const installFetchMock = (): Mock => {
+    const fetchMock = vi.fn();
+    global.fetch = withFetchPreconnect(fetchMock);
+    return fetchMock;
+  };
+
+  function mockGetMeSuccess(fetchMock: Mock) {
     fetchMock.mockResolvedValueOnce({
       ok: true,
       json: vi.fn().mockResolvedValue({
@@ -17,14 +22,14 @@ describe("probeTelegram retry logic", () => {
     });
   }
 
-  function mockGetWebhookInfoSuccess() {
+  function mockGetWebhookInfoSuccess(fetchMock: Mock) {
     fetchMock.mockResolvedValueOnce({
       ok: true,
       json: vi.fn().mockResolvedValue({ ok: true, result: { url: "" } }),
     });
   }
 
-  async function expectSuccessfulProbe(expectedCalls: number, retryCount = 0) {
+  async function expectSuccessfulProbe(fetchMock: Mock, expectedCalls: number, retryCount = 0) {
     const probePromise = probeTelegram(token, timeoutMs);
     if (retryCount > 0) {
       await vi.advanceTimersByTimeAsync(retryCount * 1000);
@@ -36,17 +41,6 @@ describe("probeTelegram retry logic", () => {
     expect(result.bot?.username).toBe("test_bot");
   }
 
-  beforeEach(() => {
-    vi.useFakeTimers();
-    fetchMock = vi.fn();
-    global.fetch = withFetchPreconnect(fetchMock);
-  });
-
-  afterEach(() => {
-    vi.useRealTimers();
-    vi.restoreAllMocks();
-  });
-
   it.each([
     {
       errors: [],
@@ -64,17 +58,26 @@ describe("probeTelegram retry logic", () => {
       retryCount: 2,
     },
   ])("succeeds after retry pattern %#", async ({ errors, expectedCalls, retryCount }) => {
+    const fetchMock = installFetchMock();
+    vi.useFakeTimers();
+    try {
       for (const message of errors) {
         fetchMock.mockRejectedValueOnce(new Error(message));
       }
 
-    mockGetMeSuccess();
+      mockGetMeSuccess(fetchMock);
-    mockGetWebhookInfoSuccess();
+      mockGetWebhookInfoSuccess(fetchMock);
-    await expectSuccessfulProbe(expectedCalls, retryCount);
+      await expectSuccessfulProbe(fetchMock, expectedCalls, retryCount);
+    } finally {
+      vi.useRealTimers();
+    }
   });
 
   it("should fail after 3 unsuccessful attempts", async () => {
+    const fetchMock = installFetchMock();
+    vi.useFakeTimers();
     const errorMsg = "Final network error";
+    try {
       fetchMock.mockRejectedValue(new Error(errorMsg));
 
       const probePromise = probeTelegram(token, timeoutMs);
@@ -87,9 +90,13 @@ describe("probeTelegram retry logic", () => {
       expect(result.ok).toBe(false);
       expect(result.error).toBe(errorMsg);
       expect(fetchMock).toHaveBeenCalledTimes(3); // 3 attempts at getMe
+    } finally {
+      vi.useRealTimers();
+    }
   });
 
   it("should NOT retry if getMe returns a 401 Unauthorized", async () => {
+    const fetchMock = installFetchMock();
     const mockResponse = {
       ok: false,
       status: 401,