fix: normalize abort signals for fetch

src/telegram/fetch.test.ts

@@ -0,0 +1,37 @@
+import { describe, expect, it, vi } from "vitest";
+
+import { resolveTelegramFetch } from "./fetch.js";
+
+describe("resolveTelegramFetch", () => {
+  it("wraps proxy fetch to normalize foreign abort signals", async () => {
+    let seenSignal: AbortSignal | undefined;
+    const proxyFetch = vi.fn(async (_input: RequestInfo | URL, init?: RequestInit) => {
+      seenSignal = init?.signal as AbortSignal | undefined;
+      return {} as Response;
+    });
+
+    const fetcher = resolveTelegramFetch(proxyFetch);
+    expect(fetcher).toBeTypeOf("function");
+
+    let abortHandler: (() => void) | null = null;
+    const fakeSignal = {
+      aborted: false,
+      addEventListener: (event: string, handler: () => void) => {
+        if (event === "abort") abortHandler = handler;
+      },
+      removeEventListener: (event: string, handler: () => void) => {
+        if (event === "abort" && abortHandler === handler) abortHandler = null;
+      },
+    } as AbortSignal;
+
+    const promise = fetcher!("https://example.com", { signal: fakeSignal });
+    expect(proxyFetch).toHaveBeenCalledOnce();
+    expect(seenSignal).toBeInstanceOf(AbortSignal);
+    expect(seenSignal).not.toBe(fakeSignal);
+
+    abortHandler?.();
+    expect(seenSignal?.aborted).toBe(true);
+
+    await promise;
+  });
+});

src/telegram/fetch.ts

@@ -1,13 +1,13 @@
-import { wrapFetchWithAbortSignal } from "../infra/fetch.js";
+import { resolveFetch } from "../infra/fetch.js";
 
 // Bun-only: force native fetch to avoid grammY's Node shim under Bun.
 export function resolveTelegramFetch(proxyFetch?: typeof fetch): typeof fetch | undefined {
-  if (proxyFetch) return wrapFetchWithAbortSignal(proxyFetch);
-  const fetchImpl = globalThis.fetch;
+  if (proxyFetch) return resolveFetch(proxyFetch);
   const isBun = "Bun" in globalThis || Boolean(process?.versions?.bun);
   if (!isBun) return undefined;
+  const fetchImpl = resolveFetch();
   if (!fetchImpl) {
     throw new Error("fetch is not available; set channels.telegram.proxy in config");
   }
-  return wrapFetchWithAbortSignal(fetchImpl);
+  return fetchImpl;
 }