fix: normalize abort signals for telegram fetch

src/infra/fetch.test.ts

@@ -0,0 +1,36 @@
+import { describe, expect, it, vi } from "vitest";
+
+import { wrapFetchWithAbortSignal } from "./fetch.js";
+
+describe("wrapFetchWithAbortSignal", () => {
+  it("converts foreign abort signals to native controllers", async () => {
+    let seenSignal: AbortSignal | undefined;
+    const fetchImpl = vi.fn(async (_input: RequestInfo | URL, init?: RequestInit) => {
+      seenSignal = init?.signal as AbortSignal | undefined;
+      return {} as Response;
+    });
+
+    const wrapped = wrapFetchWithAbortSignal(fetchImpl);
+
+    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 = wrapped("https://example.com", { signal: fakeSignal });
+    expect(fetchImpl).toHaveBeenCalledOnce();
+    expect(seenSignal).toBeInstanceOf(AbortSignal);
+    expect(seenSignal).not.toBe(fakeSignal);
+
+    abortHandler?.();
+    expect(seenSignal?.aborted).toBe(true);
+
+    await promise;
+  });
+});

src/infra/fetch.ts

@@ -0,0 +1,29 @@
+export function wrapFetchWithAbortSignal(fetchImpl: typeof fetch): typeof fetch {
+  return (input: RequestInfo | URL, init?: RequestInit) => {
+    const signal = init?.signal;
+    if (!signal) return fetchImpl(input, init);
+    if (typeof AbortSignal !== "undefined" && signal instanceof AbortSignal) {
+      return fetchImpl(input, init);
+    }
+    if (typeof AbortController === "undefined") {
+      return fetchImpl(input, init);
+    }
+    if (typeof signal.addEventListener !== "function") {
+      return fetchImpl(input, init);
+    }
+    const controller = new AbortController();
+    const onAbort = () => controller.abort();
+    if (signal.aborted) {
+      controller.abort();
+    } else {
+      signal.addEventListener("abort", onAbort, { once: true });
+    }
+    const response = fetchImpl(input, { ...init, signal: controller.signal });
+    if (typeof signal.removeEventListener === "function") {
+      void response.finally(() => {
+        signal.removeEventListener("abort", onAbort);
+      });
+    }
+    return response;
+  };
+}